Industrial Solutions Guide Edition 1.
Industrial: Solutions Guide A message from the CEO A message from the CEO Dear Customers, Over 27 years ago Maxim was built on the foundation of providing high-quality integrated circuits for products in the industrial marketplace. In fact, I started designing some of Maxim’s first data converters in 1984. Maxim continues to build on its industrial foundation, with more than 25% of its $2 billion revenue coming today from industrial products.
Industrial: Solutions Guide A message from the CEO ii Maxim Industrial Solutions
Industrial: Solutions Guide Table of contents Table of contents Programmable logic controllers (PLCs) Overview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Analog input function . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
Industrial: Solutions Guide Table of contents iv Maxim Industrial Solutions
PLCs
Programmable logic controllers (PLCs) Overview Overview new and tougher demands on a PLC: higher performance, smaller form factor, and greater functional flexibility. There must be built-in protection against the potentially damaging electrostatic discharge (ESD), electromagnetic interference and radio frequency interference (RFI/EMI), and high-amplitude transient pulses found in the harsh industrial setting.
Programmable logic controllers (PLCs) Overview makes system communications easy. Expanding on this concept is a household forced-air heater with a remote thermostat. Here the communication paths are just a few meters and a voltage control is typically utilized. FAN THERMOSTAT FAN HEATER ELEMENT Think now beyond a small, relatively simple process-control system. What controls and configuration are necessary in a factory? The resistance of long wires, EMI, and RFI make voltage-mode control impractical.
Programmable logic controllers (PLCs) Overview modules; the exact content of each of these modules will likely be as diverse as are the applications. Many modules have multiple functions that can interface with multiple sensor interfaces. Yet other modules or expansion modules are often dedicated to a specific application such as a resistance temperature detector (RTD), sensor, or thermocouple sensor.
Programmable logic controllers (PLCs) Analog input function Analog input function Overview The analog input portion of a PLC accepts analog signals from a variety of sensors and factory or field wiring. These sensors are used to convert physical phenomena such as light, temperature, sound, gas, or vibration from mechanical signals into electrical representations.
Programmable logic controllers (PLCs) Analog input function dictates the ADC’s maximum sampling rate. The signal-to-noise ratio (SNR) and spurious-free dynamic range (SFDR) specifications dictate the ADC’s resolution, filtering requirements, and gain stages. It is also important to determine how the ADC will interface to the microcontroller or CPU. For example, high-bandwidth applications perform better using a parallel or fast serial interface.
Programmable logic controllers (PLCs) Analog input function should be rejected before the gain stages. This is best accomplished using Maxim’s PGAs or differential amplifiers with a high commonmode rejection ratio (CMRR). Maxim has a variety of laser-trimmed, matching resistor-dividers for precise gain and attenuation; there are also trimmable calibration potentiometers 8 for programmability, and ADCs with differential inputs and PGAs integrated in a single IC.
Programmable logic controllers (PLCs) Analog input function Eliminate external overvoltage protection (OVP) circuitry and reduce BOM complexity with high-voltage multiplexers MAX14752/MAX14753 Benefits The MAX14752/MAX14753 are 8-to-1 and dual 4-to-1 (respectively) high-voltage analog multiplexers designed for high-voltage PLC applications. Both devices operate with dual supplies of ±10V to ±36V or a single supply of 20V to 72V, and a low 0.03Ω (typ) RON flatness.
Programmable logic controllers (PLCs) Analog input function Improve accuracy with precision over time and precision over temperature from ultra-high-precision op amps MAX4238/MAX4239 Benefits The MAX4238/MAX4239 are low-noise, low-drift, ultra-high-precision amplifiers. They offer near-zero DC offset and drift by using patented autocorrelating zeroing techniques.
Programmable logic controllers (PLCs) Analog input function Reduce component count with precision differential PGA that supports positive and negative sensor signals MAX9939 Benefits The MAX9939 is a precision, differential-input PGA ideal for conditioning wide-dynamic-range signals like those found in automotive current sense, medical instrumentation, and industrial dataacquisition applications. The MAX9939 features SPI-programmable differential gains from 0.
Programmable logic controllers (PLCs) Analog input function 16-bit ADC with software-programmable input ranges on each ADC channel saves design time MAX1300*/MAX1301/MAX1302*/MAX1303 Benefits The MAX1300–MAX1303 ADC family is an ideal fit for PLC applications because they measure many unique unipolar and bipolar input ranges, all with 16-bit operation and no missing codes. The eight single-ended or differential input ranges vary from as low as a unipolar 0 to 2.048V full scale up to a bipolar ±12.
Programmable logic controllers (PLCs) Analog input function ADC eases firmware complexity by capturing accurate phase and magnitude information on up to 32 channels MAX11040 Benefits The MAX11040 sigma-delta ADC offers 117dB SNR, four differential channels, and simultaneous sampling that is expandable to 32 channels (eight MAX11040 ADCs in parallel). With programmable phase and sampling rate, the MAX11040 is ideal for high-precision, phase-critical measurements within a noisy PLC environment.
Programmable logic controllers (PLCs) Analog output functions Analog output functions Overview understand the necessity of controlling full-scale gain variations and the multiple reset levels for bipolar and unipolar voltages and different output-current levels. The analog output remotely controls activities and functions. It can be part of a complex loop like a PLC or a proportional-integral-derivative (PID) system, or it can perform a simple function such as turning a light or fan on and off.
Programmable logic controllers (PLCs) Analog output functions momentary cable interruption, but that is not necessarily the case. The mechanical cable interruption will tend to last longer than the noise pulse. The noise pulse is typically caused by capacitive or inductive coupling of a large change in current in a second cable running close to the communications cable.
Programmable logic controllers (PLCs) Analog output functions Eliminate 31 DACs and reduce system cost with a 32-output sample/hold amplifier MAX5167 Benefits The MAX5167 contains 32 buffered sample/hold amplifier circuits with internal hold capacitors. The internal hold capacitors minimize leakage current, dielectric absorption, feedthrough, and required board space. The hold capacitors also provide fast 2.5μs (typ) acquisition time while maintaining a relatively low 1mV/s (typ) droop rate.
Programmable logic controllers (PLCs) Analog output functions System flexibility and reduced cost with multichannel DACs MAX5134/MAX5135/MAX5136/MAX5137 Benefits The MAX5134–MAX5137 are pin- and software-compatible, 16-bit and 12-bit DACs offering low power, buffered voltage output, and high linearity. They use a precision internal reference or a precision external reference for rail-to-rail operation. The MAX5134–MAX5137 accept a wide 2.7V to 5.
Programmable logic controllers (PLCs) Analog output functions Enhance system safety and reliability with an output conditioner MAX15500/MAX15501 Benefits The MAX15500/MAX15501 analog output conditioners provide a programmable current up to ±24mA, or a voltage up to ±12V proportional to a control voltage signal. The control voltage is typically supplied by an external DAC with an output voltage range of 0 to 4.096V (MAX15500) and 0 to 2.5V (MAX15501).
Programmable logic controllers (PLCs) Analog output functions 16-bit DAC with integrated voltage-and current-output conditioner reduces board area and eliminates external components MAX5661 Benefits The MAX5661 DAC controls output voltage, output current, and output gain adjustments. This device reduces the challenges that designers face when laying out their analog and mixed-signal boards.
Programmable logic controllers (PLCs) Analog output functions Improve system accuracy for high-voltage applications in a harsh environment with high-precision output conditioners and drivers MAX9943/MAX9944 Benefits The MAX9943/MAX9944 are high-voltage amplifiers (6V to 38V) that offer precision (100µVOS), low drift (0.4µV/°C), and low 550µA power consumption. The devices are ideal for sensor signal conditioning, high-performance industrial instrumentation, and loop-powered systems (e.g.
Programmable logic controllers (PLCs) Analog output functions Resistor network saves cost and space without sacrificing system precision MAX5490/MAX5491/MAX5492 Benefits The MAX5490 family of precision resistor-dividers consists of two accurately matched resistors with access to the ends and center of the divider. This family offers excellent resistance matching of 0.035% (A grade), 0.05% (B grade), and 0.1% (C grade).
Programmable logic controllers (PLCs) Analog output functions Save space in low-power process-control equipment with a single-chip HART modem DS8500 Benefits The DS8500 is a single-chip modem with HART capabilities that satisfy the HART physical-layer requirements. This device operates in half-duplex fashion, and integrates the modulation and demodulation of the 1200Hz/2200Hz FSK signal while consuming very low power.
Programmable logic controllers (PLCs) Fieldbus functions Fieldbus functions Overview A fieldbus is the communication medium used in industrial automation systems and in process control to interconnect subsystems that are spatially dispersed. Distributed control allows local, hierarchical control. There is an important advantage of such a noncentralized control strategy: it avoids high processing power and extensive cabling. Control subsystems can be located close to the sensors and actuators in the field.
Programmable logic controllers (PLCs) Fieldbus functions In the fieldbus module the controller converts the backplane protocol to the fieldbus protocol. Universal asynchronous receiver-transmitters (UARTs) define the fieldbus data rates, ensure data integrity, and interface to either the RS-485 or PROFIBUS transceivers. Harsh conditions typical of industrial applications can make protecting the interface cabling and devices a challenge.
Programmable logic controllers (PLCs) Fieldbus functions Transceiver meets PROFIBUS DP standards and protects against ±35kV ESD MAX14770E Benefits The MAX14770E PROFIBUS DP transceiver meets strict PROFIBUS standards with a high-output-drive differential (greater than 2.1V) and an 8pF bus capacitance. The high-ESD protection (±35kV, HBM), high-automotive-temperature grade, and space-saving 8-pin TQFN package make the MAX14770E ideal for space-constrained, harsh industrial environments.
Programmable logic controllers (PLCs) Fieldbus functions RS-485 transceivers with integrated termination simplify equipment installation MAX13450E*/MAX13451E* Benefits RS-485 half-duplex and full-duplex networks operating at high data rates must have their transmission lines terminated at both ends in order to minimize reflections from termination-impedance mismatch.
Programmable logic controllers (PLCs) Fieldbus functions Isolated RS-485 transceiver reduces BOM complexity MAX3535E Benefits Galvanic isolation between the PLC’s backplane and the fieldbus is required due to the harsh conditions and large common-mode voltages that can occur between remotely located subsystems. Maxim offers RS-485 transceivers with integrated isolation based on capacitors, transformers, and optical techniques.
Programmable logic controllers (PLCs) Fieldbus functions Fault-protected RS- 485 transceivers make equipment more robust MAX13448E, MAX3440E–MAX3444E, MAX13442E/MAX13443E/MAX13444E, MAX3430 Benefits •• Reduce board space by 25% with integrated fault-protection circuitry In applications where power and data are distributed over the same cable, there is a potential for miswiring, cable shorts, or surges on the communication bus.
Programmable logic controllers (PLCs) Fieldbus functions Industry’s smallest RS-485 transceivers save board space and reduce BOM complexity MAX13485E/MAX13486E, MAX13430E– MAX13433E Benefits MAX13485E/MAX13486E •• Smallest footprint enables compact designs –– Space-saving, tiny 8-pin μDFN (2mm x 2mm) package As industrial modules become smaller, pressure mounts for PLC designers to shrink their PCBs and transition from the traditional industry-standard packages like SO, SSOP, and PDIP.
Programmable logic controllers (PLCs) Fieldbus functions Advanced SPI/I2C UART enhances system flexibility and functionality, reduces load on the microcontroller MAX3107 Benefits The MAX3107 serial UART bridges SPI or I2C to an asynchronous communication interface like RS-485, RS-232, PROFIBUS DP, or IrDA®. RS-485 and PROFIBUS DP work up to high data-rates which many UARTs embedded on today’s microcontrollers cannot support.
Programmable logic controllers (PLCs) Digital I/O functions Digital I/O functions Overview communication link is higher than typically found with analog communication. Consequently digital I/O functions allow longer cable runs at low data rates. Digital I/Os interface to industrial sensors and actuators and communicate with digitized information. The sensors and actuators are located in the field and, thus, are represented on the lowest level of the control system’s hierarchy.
Programmable logic controllers (PLCs) Digital I/O functions IO-Link master transceiver enables high-density IO-Link masters MAX14824* Benefits The MAX14824 is an IO-Link master transceiver designed for highchannel-count IO-Link port-count applications. The MAX14824 integrates an IO-Link physical interface with an additional digital input and two regulators. A high-speed 12MHz SPI interface allows fast programming and monitoring of the IO-Link interface.
Programmable logic controllers (PLCs) Digital I/O functions Simplest, most economical solution for high-port-count IO-Link systems MAX14830* Benefits The MAX14830 is an advanced quad, serial UART with 128-word FIFOs for high-port-count I/O systems like an IO-Link system. By reducing the number of signals that need be isolated, the serial I2C/SPI host interface is optimized for industrial systems that require galvanic isolation.
Programmable logic controllers (PLCs) CPU functions CPU functions Overview The CPU functions for a PLC include the processor, memory, and support circuitry required to execute the programmed instructions and communicate with the various I/O functions. System monitoring functions are performed by the CPU’s powersupply voltage monitors; watchdog timers (WDTs) and reset circuits; and thermal monitors for critical devices and hot spots.
Programmable logic controllers (PLCs) CPU functions Smallest secure microcontroller minimizes system size MAXQ1850 Benefits The MAXQ1850 is the industry’s smallest, high-security microcontroller. This single-cycle RISC processor executes 16-bit instructions and uses a 32-bit data path for unmatched processing efficiency and C code optimization.
Programmable logic controllers (PLCs) CPU functions Security managers protect encryption keys from intruders DS3600 Benefits Security managers provide comprehensive data protection. The DS3600 single-chip solution provides security, tamper detection, encryption key storage, and encryption key destruction in the event of tampering. The DS3600 is packaged in a CSBGA for an added level of security. •• Improved system security –– Supports the highest security-level requirements of the FIPS 140.
Programmable logic controllers (PLCs) CPU functions 1-Wire SHA-1 authenticators securely protect control modules from unauthorized cloning or feature modification DS28E01-100, DS28E02, DS28E10 Benefits 1-Wire secure memories utilize a SHA-1-based, crypto-strong, secure challenge-and-response authentication sequence. Thus authentication enables FPGAs and CPUs to differentiate between authorized and cloned environments.
Programmable logic controllers (PLCs) Isolated power-supply functions Isolated power-supply functions Overview Power functions Typically PLCs have a backplane power rail of about 24V DC, although the actual voltage can differ, usually from 12V to 48V. The power comes from an isolated DC-DC converter connected to a factory AC-DC supply. A PLC can be equipped with an auxiliary battery with a special OR-ing controller.
Programmable logic controllers (PLCs) Isolated power-supply functions Simplify industrial-bus power design with integrated hot-swap controllers and FETs that power devices MAX5042/MAX5043 Benefits The MAX5042/MAX5043 are isolated, multimode, pulse-widthmodulated (PWM) power ICs. They feature integrated switching power MOSFETs connected in a voltage-clamped, two-transistor, power-circuit configuration. These devices operate from a wide 20V to 76V input voltage range.
Programmable logic controllers (PLCs) Isolated power-supply functions Reduce system downtime with current-mode PWM controller with integrated hot-swap MAX5069 Benefits The MAX5069 is a high-frequency, current-mode PWM controller with dual MOSFET drivers. The IC integrates everything necessary for implementing AC-DC or DC-DC fixed-frequency power supplies. Isolated or nonisolated, push-pull and half-/full-bridge power supplies are easily constructed using either primary- or secondaryside regulation.
Programmable logic controllers (PLCs) Isolated power-supply functions Save space and costs by integrating three switching controllers MAX15048/MAX15049 Benefits The MAX15048/MAX15049 are triple-output, PWM, step-down DC-DC controllers with tracking (MAX15048) and sequencing (MAX15049) options. The devices operate over the 4.7V to 23V input voltage range. Each PWM controller provides an adjustable output down to 0.6V and delivers up to 15A of load current with excellent load and line regulation.
Programmable logic controllers (PLCs) Isolated power-supply functions Save cost with integrated DC-DC converters that power off an industrial bus MAX5080/MAX5081 Benefits The MAX5080/MAX5081 are 250kHz, PWM, step-down DC-DC converters with an on-chip high-side switch. The input voltage range is 4.5V to 40V for the MAX5080 and 7.5V to 40V for the MAX5081. The devices’ output is adjustable from 1.23V to 32V and can deliver up to 1A of load current.
Programmable logic controllers (PLCs) Isolated power-supply functions OR-ing FET controller supports main and battery-backup power to improve system reliability MAX5079 Benefits The MAX5079 OR-ing MOSFET controller replaces OR-ing diodes in high-reliability, redundant, parallel-connected power supplies. The controller allows the use of low-RON, n-channel power MOSFETs to replace Schottky diodes. The MAX5079 operates from 2.75V to 13.2V and includes a charge pump to drive the high-side n-channel MOSFET.
Programmable logic controllers (PLCs) Isolated power-supply functions Simplify isolated power-supply design with a highly integrated transformer driver MAX256 Benefits For systems that require a low-watt, isolated power supply, a typical closed-loop switching regulator can add unnecessary cost and complexity. The MAX256 simplifies an isolated power-supply design.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions Analog input function Part Description Features Benefits Active filters MAX7409/10 5th-order, switched-capacitor, lowpass filters (Bessel or Butterworth) Clock or capacitor-adjustable corner frequency to 15kHz; 1.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits Operational amplifiers MAX9943/44 38V precision, single and dual op amps Wide 6V to 38V supply range; low 100µV (max) input offset voltage; drive 1nF loads Wide operating voltage range and precision performance under most capacitive loads MAX9945 38V CMOS-input precision op amp Wide 4.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits Voltage supervisors (continued) MAX6495 72V overvoltage protector Protects against transients up to 72V; small, 6-pin TDFN-EP package Increases system reliability by preventing component damage due to high-voltage transients; saves space; easy to use.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Analog output functions Part Description Features Benefits HART DS8500 HART modem HART compliant; integrated digital filter; 5mm x 5mm x 0.8mm TQFN package; 3.6864MHz clock; 285µA active-mode current Power-saving; single-chip solution with small PCB foot print 32-channel sample/hold amplifier with output-clamping diodes 2.5µs acquisition time; 0.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits Thermal management (continued) DS18B20 Precision 1-Wire digital temperature sensor ±0.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Fieldbus functions Part Description Features Benefits Interface transceivers MAX14770 PROFIBUS transceiver ±35kV (HBM) ESD tolerance; -40°C to +125°C automotive temperature range; small (3mm x 3mm) TQFN package Industry’s highest ESD protection makes PLC more robust MAX13450E/51E RS-485 transceivers with pin-selectable termination resistors Integrated 100Ω and 120Ω termination resistors; Allow remote con
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Digital I/O functions Part Description Features Benefits Digital I/O modules MAX14830* Quad SPI/I2C UART with 128 byte FIFOs 24Mbps (max) data rate; integrated oscillator; automatic transceiver control; 16 GPIOs; 7mm x 7mm, 48-pin TQFN package Serial Interface reduces cost for isolators; allows scalable architectures; simplifies design; reduces overall cost MAX14824* IO-Link master transceiver IO-Link m
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits MAX6381 Single-voltage supervisor Multiple threshold and timeout options Versatile for easy design reuse; saves space in small modules MAX6495 72V overvoltage protector Protects against transients up to 72V; small, 6-pin TDFN-EP package Increases system reliability by preventing component damage due to high-voltage transients; saves space; easy to use MAX6720 Triple-
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) CPU functions Part Description Features Benefits Microcontrollers MAXQ1850 32-bit secure microcontroller 256kB flash; 8kB, secure battery-backed SRAM; High security; tamper detection DES/3DES, AES; 16MHz; SPI/USB interface MAXQ1004* 1-Wire and SPI authentication 16-bit microcontroller 1.7V to 3.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits LED backlighting (continued) MAX8790A 6-channel white-LED (WLED) driver for LCD 4.5V to 26V input voltage; 15mA to 25mA (adj), panel applications full-scale LED current; adaptive boost control Compact design DS7505 Low-voltage, precision digital thermometer and thermostat ±0.5°C accuracy from 0°C to +70°C; 1.7V to 3.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Isolated power-supply functions Part Description Features Benefits DC-DC converters and controllers MAX5080/81 Step-down DC-DC converters with integrated switch 4.5V/7.5V to 40V V IN; 1.
Programmable logic controllers (PLCs) Recommended solutions Recommended solutions (continued) Part Description Features Benefits Thermal management DS7505 Low-voltage, precision digital thermometer and thermostat ±0.5°C accuracy from 0°C to +70°C; 1.7V to 3.
Sensors
Sensors Overview Overview Industrial processes use sensors to monitor physical properties. Examples include temperature in a furnace, pressure in a chamber, environmental humidity, gas or liquid flows through pipes, weights of ingredients, and current flow in motor windings. an electrical signal. Some transducers are resistive elements that require external excitation to create a measurable voltage.
Sensors Pressure sensors and weigh scales (force sensing) Pressure sensors and weigh scales (force sensing) Overview The two most common types of strain gauges are the metal-foil type used in a variety of weight/pressure sensors and the semiconductorbased piezoresistive transducers, widely used to measure pressure. Compared to metal-foil-type transducers, piezoresistive transducers are more sensitive with better linearity, but have large temperature dependence and large initial offsets.
Sensors Pressure sensors and weigh scales (force sensing) load cell) to produce a differential output voltage in response to pressure or weight. Engineers can design a sensor module that meets the unique requirements of diverse force-sensing applications. A successful design will include the suitable sensing element for the physical property and an appropriately designed signal chain. Complete signal-chain solutions The sensor signal chain must handle extremely small signals in the presence of noise.
Sensors Pressure sensors and weigh scales (force sensing) CPU, temperature sensor, and digital interface. Two types of signal conditioners are commonly used: analog signal-path conditioner (analog conditioner) and digital signal-path conditioner (digital conditioner). Analog condi- tioners have a faster response time and provide a continuous-output signal, reflecting changes on the input signal. They generally have a hardwired (inflexible) compensation scheme.
Sensors Pressure sensors and weigh scales (force sensing) Flexible ADCs interface with a wide range of sensors MAX1415/MAX1416, MX7705 Benefits Pressure sensors commonly have high temperature dependence. Therefore, the design should monitor temperature while measuring pressure. The MAX1415 features differential reference inputs which allow ratiometric measurement of the 3V excitation voltage.
Sensors Pressure sensors and weigh scales (force sensing) Maintain high accuracy over time and temperature MAX9617/MAX9618, MAX11200* Benefits One of the biggest challenges with interfacing to sensors is the low signal levels. Since the signal bandwidth (BW) lies in low hertz for many sensors, the 1/f noise of op amps is an important factor. Maxim’s MAX9617/MAX9618 low-power (< 100µA) op amps offer the industry’s lowest noise, autozero (42nV/√Hz) operation.
Sensors Pressure sensors and weigh scales (force sensing) Low-cost, high-precision sensor signal conditioner simplifies sensor design MAX1452 Benefits The MAX1452 is a versatile analog sensor signal conditioner that accepts output from all types of resistive elements. Its fully analog signal path enables a fast response and also provides current or voltage excitation for optimal design flexibility.
Sensors Pressure sensors and weigh scales (force sensing) Low-power, low-noise, multichannel sensor signal processor saves cost and board space MAX1464 Benefits The MAX1464 is a highly integrated, digital, multichannel sensor signal conditioner optimized for industrial process-control and automotive applications. Typical implementations include pressure sensing, RTD and thermocouple linearization, weight sensing/classification, and remote process monitoring with limit indication.
Sensors Pressure sensors and weigh scales (force sensing) Low-power, low-noise, multichannel sensor signal processor saves cost and board space (continued) 5V 22Ω VDD INP1 VDDF RREF SENSOR INM1 MAX1464 INP2 OUTNSM OUT, BRIDGE OUTNLG OUT, RTD GPION SYSTEM CONTROL UNIT DIGITAL INTERFACE INM2 RTD VSS RT* 0.1μf 0.1μf 100pf 100pf GND * RT is a resistor with a negligible tempco (TC) or a well-known TC .
Sensors Temperature sensing Temperature sensing Overview Thermistors, RTDs, thermocouples, and ICs are some of today’s most widely used temperature-sensing technologies. Each design approach has its own strengths (e.g., cost, accuracy, temperature range) which make it appropriate for specific applications. Each of these technologies will be discussed below. Temperature sensing is critically important for implementing three key functions in industrial systems. 1.
Sensors Temperature sensing Thermistors Thermistors are temperaturedependent resistors, usually made from semiconducting materials like metal-oxide ceramics or polymers. The most widely used thermistors have a negative temperature coefficient of resistance and, therefore, are often referred to as NTCs. There are also positive temperature coefficient (PTC) thermistors.
Sensors Temperature sensing voltage. The example circuit in Figure 3 shows one implementation, which includes a number of precision components. In addition to all of the components shown in Figure 3, Maxim manufactures the MAX6674 and MAX6675 which perform the signal-conditioning functions for K-type thermocouples. These devices simplify the design task and significantly reduce the number of components required to amplify, cold-junction compensate, and digitize the thermocouple’s output.
Sensors Temperature sensing There is an important advantage to remote temperature sensors: they allow you to monitor more than one hot spot with a single IC. A basic single remote sensor like the MAX6642 in Figure 4 can monitor two temperatures: its own and an external temperature. The external location can be on the die of a target IC, as in Figure 4, or a hot spot on a board that it monitors with a discrete transistor. Some remote sensors monitor as many as seven external temperatures.
Sensors Temperature sensing Simple, integrated RTD-to-digital conversion MAX1402, MAX4236/ MAX4237 Any appreciable resistance in the RTD’s leads will cause errors in temperature measurement. Therefore, for long wire lengths use a 3- or 4-wire connection to eliminate lead-resistance errors. The circuit in Figure A is a 4-wire RTD interface using the MAX1402 oversampling ADC. The MAX1402 has two matched current sources, which significantly reduce the IC count in an RTD converter.
Sensors Temperature sensing Complete thermocouple interface designs eliminate external components, use less space DS600, MAX1416, MAX6133, MAX6675 common-mode range extends 30mV below ground. The thermocouple circuit shown in Figure A uses the MAX1416 ADC that allows direct interfacing with thermocouples, thereby eliminating external components and reducing the overall footprint.
Sensors Temperature sensing Complete thermocouple interface designs eliminate external components, use less space (continued) For more information on temperature sensing, please refer to Maxim’s Thermal Management Handbook at: www.maxim-ic.com/thermal-handbook. 3.3V VCC 0.1µF SO GND MAX6675 SCK TO MICROCONTROLLER CS T+ T- Figure B. The MAX6675 is a complete thermocouple-to-digital converter for K-type thermocouples.
Sensors Current, light, and proximity sensing Current, light, and proximity sensing Overview These current-sensing techniques employ current-sense amplifiers which are available in multiple configurations, or transimpedance amplifiers (TIAs). Each type of current-sensing amplifier is discussed below. Current sensing is important in many applications and can be categorized into two popular approaches.
Sensors Current, light, and proximity sensing avoids extraneous resistance in the ground plane, greatly simplifies the layout, and generally improves the overall circuit performance. The variety of unidirectional and bidirectional current-sense ICs from Maxim includes devices with and without internal sense resistors. a low-input common-mode voltage, and the output voltage is ground referenced. However, the low-side sensing resistor adds undesirable extraneous resistance in the ground path.
Sensors Current, light, and proximity sensing Improve efficiency and increase reliability by monitoring a system’s power MAX9922/MAX9923, MAX11601, MAX11607, MAX11613 families Here is a very common circuit found in applications for power monitoring. The MAX9923 current-sense amplifier amplifies the differential voltage across the current-sense resistor with extremely low offset and low noise.
Sensors Current, light, and proximity sensing Save power, reduce system cost and complexity with a 22-bit, integrated ambient-light sensor MAX9635* Benefits The MAX9635 is a highly integrated ambient-light sensor with digital output. Its 1µA current consumption saves power in the system. The integrated ADC and an I2C communication channel reduce cost by eliminating external components. Space is also conserved, because this integrated solution has a 2mm x 2mm footprint.
Sensors Current, light, and proximity sensing Get precise measurements in very harsh operating environments MAX9918/MAX9919/MAX9920 Benefits The MAX9918/MAX9919/MAX9920 current-sense amplifiers provide uni-/bidirectional current sensing for very harsh environments where the input common-mode range can become negative. The amplifiers have a -20V to +75V common-mode operating range for measuring the current of inductive loads.
Sensors Current, light, and proximity sensing System diagnostics ensure longer up-time in harsh operating environments MAX4211 Benefits The MAX4211 is a full-featured, continuous current and power monitor. The device combines a high-side current-sense amplifier, 1.21V bandgap reference, and two comparators with open-drain outputs to make detector circuits for overpower, overcurrent, and/or overvoltage conditions. •• Real-time power and current monitoring enhances system reliability –– ±1.
Sensors Current, light, and proximity sensing Improve system accuracy over temperature and minimize the effects of harsh environmental noise MAX9939 Benefits The MAX9939 is a differential-input, programmable-gain amplifier (PGA). It features SPI™-programmable differential gains from 0.2V/V to 157V/V; input offset-voltage compensation for on-demand calibration; and an output amplifier that can be configured either as a high-order active filter or to provide a differential output.
Sensors Current, light, and proximity sensing Maximize system accuracy in photodiode and high-ohmic sensor applications MAX9945 Benefits The MAX9945 operational amplifier features an excellent combination of low-operating power and low-input-voltage noise. MOS inputs enable the MAX9945 to feature low 50fA input-bias currents and low (15nV/√Hz) input-current noise. The MAX9945 simplifies the interface between high-ohmic sensors or low-current TIA applications.
Sensors Hall-effect sensors Hall-effect sensors Overview Hall-effect sensors are used in motor applications where the speed, position, and direction of motors can be sensed and communicated to the system for real-time feedback. If there is an interruption to the motor, the sensor detects it so corrective action can be taken. Typically, to detect the direction of movement, two Hall-effect sensors are used.
Sensors Hall-effect sensors Simplify motion detection and system design with dual Hall-effect switch MAX9641* Benefits The MAX9641 is an ultra-low-power, dual, Hall-effect switch with adjustable threshold operation and selectable sampling frequency. Three programmable sampling periods (160µs, 500µs, and 50ms) provide flexibility for choosing the operating speed. The operating point of the Hall-effect switch can be easily adjusted to three points by setting the adjust pin.
Sensors Sensor communications interface Sensor communications interface A sensor communicates its sensed information with analog or digital techniques. Analog techniques are based on voltage or current loops. Digital information is communicated with CAN, CompoNet®, IO-Link®, RS-485, and other data interfaces.
Sensors Sensor communications interface Fault-protected RS-485 transceivers make equipment more robust MAX13448E, MAX3440E–MAX3444E, MAX13442E/MAX13443E/MAX13444E, MAX3430 Benefits In applications where power and data are distributed over the same cable, there is a potential for miswiring, cable shorts, or surges on the communication bus. Maxim’s RS-485 transceivers offer fault protection up to ±80VDC . DE •• Flexible configurations interface with multiple systems –– Wide 3.
Sensors Sensor communications interface Reduce PCB footprint with an IO-Link/binary sensor interface MAX14820* Benefits The MAX14820 is a transceiver with a 24V binary interface for sensors and actuators. Designed for IO-Link device applications, it supports all the specified IO-Link data rates. The MAX14820 contains additional 24V digital inputs and outputs (I/Os). Two regulators generate common sensor signals and conditioning power requirements: 5V and 3.3V.
Sensors Recommended solutions Recommended solutions Pressure sensors and weigh scale Part Description Features Benefits ADCs MAX1415/16 MX7705 16-bit, low-power, 2-channel, sigma- Two differential channels; PGA; single-supply delta ADCs operation Highly flexible ADC; interfaces with a wide range of sensors MAX1400/01/02/03 18-bit, 5-channel delta-sigma ADCs Three differential channels; PGA; precision current sources for excitation; burn-out detection High integration produces a more precise senso
Sensors Recommended solutions Recommended solutions (continued) Temperature sensing Part Description Features Benefits Thermal management DS600 Precision analog-output temperature Industry’s highest accuracy analog temp sensor: sensor ±0.5°C from -20ºC to +100ºC Best cold-junction compensation accuracy for superior thermocouple measurement DS7505 Low-voltage, precision, digital thermometer and thermostat ±0.5°C accuracy from 0ºC to +70ºC; 1.7V to 3.
Sensors Recommended solutions Recommended solutions (continued) Light sensing Part Description Features Benefits ADCs MAX1168/67 MAX1162 16-bit, 200ksps, 8-/4-/1-channel SAR ADCs 16-bits, no missing codes; single 5V supply; unipolar 0 to 5V input range Flexible and accurate solution for multichannel applications MAX11200*/01*/02* Ultra-low-power, sigma-delta ADCs 21-bit noise-free range at10sps; 3V supply; 0.
Sensors Recommended solutions Recommended solutions (continued) Current sensing Part Description Features Benefits ADCs MAX11600– MAX11605 Multichannel, low-power, ADCs with I2C interface Low cost; 8-/12-bit; 4-/8-/12-channels; differential Sense multiple currents and voltages at low cost inputs; low power (6µA at 1ksps);I2C MAX11606– MAX11611 MAX11612– MAX11617 MAX11618*– MAX11625* Multichannel, FIFO ADCs with an SPI Low cost; 8-/12- bit; 8-/12-/16-channels; interface differential inputs; internal
Sensors Recommended solutions Recommended solutions (continued) Hall-effect sensors Part Description Features Benefits Amplifiers MAX9639* Ultra-low-power, Hall-effect sensor 50ms sampling rate; 1.7V to 5.5V operation; three threshold points of 1.5mT, 3mT, and 5mT Integrated sensor and amplifier reduce cost MAX9640* Ultra-low-power, Hall-effect sensor 50ms sampling rate; 1.7V to 5.
Motor control
Motor Control Overview Overview DC motors: low cost and accurate drive performance Electric motors consume almost 50% of the world’s electricity. With the cost of energy rising steadily, industry is focused on replacing inefficient constant-speed motors and drives with microprocessor-based, variablespeed drives. This new motor-control technology will reduce energy consumption by more than 30% compared to the older drives.
Motor Control Overview AC induction motors: simplicity and ruggedness An AC induction motor is popular in industry because of its simplicity and ruggedness. In its simplest form, this motor is a transformer with the primary-side voltage connected to the AC-power-voltage source and the secondary side shorted to carry the induced secondary current. The name “induction” motor derives from this induced secondary current.
Motor Control Monitoring and measuring current for optimal motor control Monitoring and measuring current for optimal motor control Current monitoring Current is a common signal to be sensed, monitored, and fed back to the motor-control loop. Currentsense amplifiers make it easier to monitor the current into and out of the system with a high level of precision. If current-sense amplifiers are used, no transducer is needed, as the electrical signal itself is being measured.
Motor Control Monitoring and measuring current for optimal motor control Precise current measurements ensure better motor control MAX9918/MAX9919/MAX9920 Benefits The MAX9918/MAX9919/MAX9920 are current-sense amplifiers with a -20V to +75V input range. The devices provide unidirectional/ bidirectional current sensing in very harsh environments where the input common-mode range can become negative. Uni-/bidirectional current sensing measures charge and discharge current in a system.
Motor Control Sensing motor speed, position, and movement Sensing motor speed, position, and movement Overview Hall-effect sensors are used to sense the speed, position, and direction of motors. With integrated device logic, the sensors then communicate that data to the system for real-time feedback. The sensor also detects and reports any interruption to the motor so corrective action can be taken. Typically, to detect the direction of movement two Halleffect sensors are used.
Motor Control Sensing motor speed, position, and movement Simplify system design with flexible operating inputs MAX9641* Benefits The MAX9641 is an ultra-low-power, dual Hall-effect switch. Three programmable sampling periods of 160µs, 500µs, and 50ms give the designer flexibility to choose the operating speed. By setting the adjust pin, the MAX9641’s operating point can be easily adjusted to three points which accommodate many different magnetic materials.
Motor Control Sensing motor speed, position, and movement Highly accurate, reliable monitoring of motor speed and position with a sensor interface MAX9621 Benefits The MAX9621 is a dual, 2-wire Hall-effect sensor interface with analog and digital outputs. This device enables a microprocessor to monitor the status of two Hall-effect sensors, either through the analog output by mirroring the sensor current for linear information, or through the filtered digital output.
Motor Control Sensing motor speed, position, and movement Improve performance and reliability in motor applications with a differential VR sensor interface MAX9924–MAX9927 Benefits The MAX9924–MAX9927 VR, or magnetic coil, sensor interface devices are ideal for sensing the position and speed of motor shafts, camshafts, transmission shafts, and other rotating wheel shafts.
Motor Control Monitoring and controlling multichannel currents and voltages Monitoring and controlling multichannel currents and voltages Overview To monitor and control a motor, multiple currents and voltages need to be measured and the phase integrity between the channels preserved. Designers are faced with two choices for the ADC architecture: use multiple singlechannel ADCs in parallel, a design that makes it very difficult to synch up the conversion timing; or use a simultaneous-sampling ADC.
Motor Control Monitoring and controlling multichannel currents and voltages Resolve very fine motor adjustments and operate higher accuracy systems with simultaneous-sampling ADCs MAX11044/MAX11045/MAX11046 MAX11047/MAX11048/MAX11049 Benefits The MAX11044–MAX11049 ADCs are an ideal fit for motor-control applications that require a wide dynamic range.
Motor Control Monitoring and controlling multichannel currents and voltages Detect errant motor shifts quickly by sampling at 1.25Msps MAX1377/MAX1379/MAX1383 Benefits The MAX1377/MAX1379/MAX1383 integrate a pair of successive approximation register (SAR) ADCs that simultaneously sample a pair of differential inputs. This design allows a voltage and current pair to be sampled with the phase integrity between the two channels preserved.
Motor Control High-accuracy motor control with encoder data interfaces High-accuracy motor control with encoder data interfaces Overview The accuracy with which a motor needs to be controlled depends on the system requirements. In some applications the accuracy requirements are very high, as in industrial robotics or in bottling. A welding robot, for example, is expected to operate with high speed and high precision.
Motor Control High-accuracy motor control with encoder data interfaces Make equipment more robust with fault-protected RS-485 transceivers MAX13448E, MAX3440E–MAX3444E, MAX13442E/MAX13443E/MAX13444E, MAX3430 Benefits •• Integrated fault protection to ±80VDC allows smaller encoder designs –– Saves board space and cost of discrete protection circuitry –– High-speed RS-485 requirements are met despite fault protection –– Reduces field returns due to misconnection •• Multiple configurations increase design fl
Motor Control High-accuracy motor control with encoder data interfaces Extend cable lengths in harsh motor-control environments with high-speed RS-485 transceivers MAX14840E/MAX14841E Benefits The MAX14840E/MAX14841E are 3.3V high-speed (40Mbps), halfduplex RS-485 transceivers ideally suited for industrial applications where extended-cable-length communication is required. The MAX14840E features a symmetrical fail-safe receiver and larger receiver hysteresis.
Motor Control High-accuracy motor control with encoder data interfaces Transceiver meets PROFIBUS DP standards and protects against ±35kV ESD MAX14770E Benefits The MAX14770E PROFIBUS DP transceiver meets strict PROFIBUS standards with a high-output-drive differential (greater than 2.1V) and an 8pF bus capacitance. The high-ESD protection (±35kV, HBM), high-automotive-temperature grade, and space-saving 8-pin TQFN package make the MAX14770E ideal for space-constrained, harsh industrial environments.
Motor Control Recommended solutions Recommended solutions Part Description Features Benefits ADCs MAX11044/45/46 MAX11047/48/49 16-bit, 4-/6-/8-channel, simultaneous-sampling SAR ADCs 93dB SNR; -105dB THD; 0 to 5V or ±5V inputs; parallel interface outputs, all eight data results in 250ksps; high-input impedance ( > 1MΩ) High-impedance input saves the cost and space of external amplifier MAX1377/MAX1379/ MAX1383 12-bit, 1.
Motor Control Recommended solutions Recommended solutions (continued) Part Description Features Benefits Voltage supervisors MAX6381 Single-voltage supervisor Multiple threshold and timeout options Versatile for easy design reuse; SC70 package saves board space MAX6495 72V overvoltage protector Protects against transients up to 72V; small 6-pin TDFN-EP package Increases system reliability by preventing component damage from high-voltage transients; saves space; easy to use MAX6720 Triple-volta
Motor Control Recommended solutions 112 Maxim Industrial Solutions
Security and surveillance
Security and surveillance Digital video recorders (DVRs) Digital video recorders (DVRs) Overview Analog CCTV security systems are moving to digital technology, and video recording is leading this transition. The analog VCR has been replaced by digital video recorders (DVRs) in security systems that require video monitoring and recording. DVRs now offer overwhelming advantages over analog VCRs in security applications.
Security and surveillance Digital video recorders (DVRs) the available network bandwidth without efficient compression. DVR system designs without H.264 often rely on reduced-frame-rate or lower resolution recording techniques that degrade picture quality in order to increase recording time and reduce video bit rates. Older codec formats (MPEG-4 and MJPEG) are often still required for legacy support, but the industry’s trend to adopt H.264 as the primary codec in DVR is well under way. Maxim’s family of H.
Security and surveillance Digital video recorders (DVRs) H.264 video codec system-on-a-chip (SoC) simplifies multichannel DVR system designs while providing excellent video quality MG3500 Benefits The MG3500 is a highly integrated, HD or multichannel SD, H.264 codec SoC ideally suited for the security DVR market. It offers a fully compliant baseline, main, and high-profile HD H.
Security and surveillance Digital video recorders (DVRs) H.
Security and surveillance Digital video recorders (DVRs) Video decoder provides superior video quality MAX9526 Benefits The MAX9526 low-power video decoder was designed to support multiple video (NTSC/PAL) standards, making it ideal for security and surveillance systems.
Security and surveillance Digital video recorders (DVRs) Recommended solutions Part Description Features Benefits Video codec MG3500 H.264 video codec SoC Video formats: HD 1080p30 H.264 codec, MJPEG codec; audio formats: AAC, AMR, Dolby ®, G.7xx, MP1/2/3; HD MPEG-2 decoder, 4 D1 + 4 CIF H.264 encoders or 8 D1 H.
Security and surveillance Digital video recorders (DVRs) Recommended solutions (continued) Part Description Features Benefits RTCs DS1315 Phantom time chip Real-time clock (RTC); nonvolatile memory controller Integrated clock and memory controller save space and provide design flexibility; phantom interface allows communication over parallel bus with no address space requirements DS1500 Watchdog timekeeper with nonvolatile memory control Programmable watchdog timer; time-of-day alarm; power-contr
Security and surveillance Digital video recorders (DVRs) 122 Maxim Industrial Solutions
Security and surveillance IP cameras IP cameras Overview Low-power camera designs can be powered over Ethernet (PoE) without additional power sources. By using the same cable to transmit both data and power, PoE installations can substantially reduce cabling costs. In some cases, wireless networks such as Wi-Fi® can be used to replace Ethernet, thus easing camera placement.
Security and surveillance IP cameras Embedded Linux® software and networking IP cameras need to provide the capability for streaming video to multiple clients. For example, Maxim’s IP camera reference design (Mobicam3) supports up to 16 clients and both the real-time transport protocol (RTP) and the real-time streaming protocol (RTSP). The following Ethernet protocols are also supported: HTTP, DHCP, SMTP, TCP/IP, UDP, TFTP, FTP, NTP, and UPnP™.
Security and surveillance IP cameras High-definition H.264 codec SoC supports multistream applications with intelligent analytics MG2580 Benefits Maxim’s Mobicam3 IP camera reference design uses the MG2580 codec SoC to perform multistream H.264 compression, M-JPEG compression, analytics, AES/SHA video encryption, and Ethernet communication functions on a single chip. The MG2580 can compress three H.264 streams simultaneously at CIF, D1, and 720p resolutions.
Security and surveillance IP cameras Recommended solutions Part Description Features Benefits Video codec MG2580 H.264 HD codec SoC H.264 and M-JPEG encoding, ARM9 processor, Ethernet, USB, audio codecs (G.
Security and surveillance IP cameras Recommended solutions (continued) Part Description Features Benefits Real-time clocks (RTCs) DS1340 I2C RTC with trickle charger Automatic backup power switching DS1390 Low-voltage SPI™/3-wire RTC with trickle charger Automatic backup power switching, time-of-day alarm Reliable timekeeping during power-supply interruptions DS1318 44-bit binary counter Resolution of 244µs; counter can be configured as an event counter or RTC Reliable event tracking during p
Security and surveillance IP cameras 128 Maxim Industrial Solutions
LED lighting
Lighting LED lighting LED lighting The expanding role for LED lighting Light-emitting diodes (LEDs) are a rapidly evolving technology and are becoming viable for many general lighting applications, usually referred to as solid-state lighting.
Lighting LED lighting electrical infrastructure (i.e., cabling, transformers, dimmers, and sockets), a significant advantage for LED technology. Fitting an LED lamp into the existing infrastructure challenges the designer in two principal ways: 1. The form factor. Retrofit lamps must fit in the form factor of the previous light source. 2. Electrical compatibility. Retrofit lamps must work correctly and without light flicker in the existing electrical infrastructure.
Lighting LED lighting than 0.9 power-factor correction and require a very limited number of external components. No electrolytic capacitors are required, which considerably extends the lifetime of the driver circuit working in a hot environment. Both the 120VAC/230VAC and 12VAC solutions employ the MAX16834 IC, and are available for evaluation and use in mass production. They are both proprietary to Maxim, which is the only supplier to provide this combination of advantages.
Lighting LED lighting • Low costs. This is true for most lighting applications. A remote-controlled lamp often includes a microcontroller, either as a discrete component or integrated in another IC. Unless a complex communication protocol is adopted with a complex stack (e.g., ZigBee®), a basic microcontroller is typically sufficient.
Lighting LED lighting Industrial-grade LED drivers reduce external component count MAX16822/MAX16832 Benefits The MAX16822/MAX16832 are high-input-voltage, buck-mode, high-brightness (HB) LED drivers for up to 1A or 500mA current. With hysteretic control of the LED current, they do not need a compensation circuit. They require very few external components, thus reducing BOM cost and board area substantially compared to other solutions.
Lighting LED lighting HB LED drivers reduce BOM cost MAX16819/MAX16820 Benefits The MAX16819/MAX16820 are buck-mode HB LED drivers featuring an external switching MOSFET for applications with more than 1A current. They provide hysteretic control of the LED current so that they do not need a compensation circuit. They require very few external components, are low in cost, and are available in a small package size (3mm x 3mm).
Lighting LED lighting Highly flexible HB LED driver provides ideal light intensity over widely varying ambient-light conditions MAX16834 Benefits The MAX16834 is a highly flexible HB LED driver that can work in buck, buck-boost, boost, SEPIC, and flyback configurations. It uses current-mode control of the LED current. By including a driver for a dimming pass MOSFET, it allows a 3000:1 PWM dimming range.
Lighting LED lighting 16-bit MAXQ® microcontroller greatly extends battery life in portable equipment MAXQ610 Benefits The MAXQ610 is designed for low-cost, high-performance, batterypowered applications. This 16-bit, RISC-based microcontroller has a wide operating range (down to 1.7V) for long battery life and ultra-low power consumption. Its anticloning features and secure MMU enable you to protect your IP. •• Ultra-low supply current minimizes power consumption –– Active mode: 3.
Lighting LED lighting Recommended solutions Part Description Features Benefits LED power MAX16822 500mA, buck, switch-mode driver with integrated MOSFET 6.5V to 65V input; LED current thermal foldback; few external components Small board area; low BOM cost MAX16832 1A, buck, switch-mode driver with integrated MOSFET 6.
Lighting LED lighting 140 Maxim Industrial Solutions
Related functions
Related functions Trim, calibrate, and adjust Trim, calibrate, and adjust Making industrial equipment accurate, safe, and affordable with electronic calibration We demand safety in our factories. Customers expect quality products, which require accurate manufacturing equipment. At the same time, equipment must be affordable. How can manufacturers deliver “perfect” equipment at a reasonable price? In a word, calibration.
Related functions Trim, calibrate, and adjust from the gross weight is necessary to accurately measure the net weight of the material on the scale. Because the weight of the package may change over time due to manufacturing variation or a change of vendors, it is desirable to update the tare or container weight from time to time. Another example is using a switch to short an amplifier input to ground to measure offset voltage. This could be done during power-on self-test to compensate for component aging.
Related functions Trim, calibrate, and adjust frequently or over longer equipment lifespans, since they can guarantee 50,000 writing cycles. The best mechanical pots can support only a few thousand adjustments. Location flexibility and size are other advantages compared to mechanical pots. Digitally adjustable pots can be mounted on the circuit board directly in the signal path, exactly where they are needed.
Related functions Trim, calibrate, and adjust “Just-in-time” inventory control is more important today than it has ever been because getting the order may hinge on quick delivery time. Winning an order when a competitor fails to deliver can lead to repeat orders. Plus, increasing inventory turns increased profit directly to the bottom line. 146 Summary Calibration is a means to an end.
Related functions Trim, calibrate, and adjust Recommended solutions Part Description Features Benefits CDPots MAX5481 1024-tap (10-bit) CDPot with SPI™ or up/ down interface 1.0µA (max) in standby, 400µA (max) during memory write Minimal power use for battery-operated portable devices MAX5477 Dual, 256-step (8-bit) CDPot with I2C interface EEPROM write protection, single-supply operation (2.7V to 5.
Related functions Trim, calibrate, and adjust 148 Maxim Industrial Solutions
Legal notices
Legal notices Trademark information Trademark information μMAX is a registered trademark of Maxim Integrated Products, Inc. 1-Wire is a registered trademark of Maxim Integrated Products, Inc. ARM9 is a trademark of ARM Ltd. ARM926 is a trademark of ARM Ltd. CompactFlash is a registered trademark of SanDisk Corp. CompoNet is a registered trademark of OMRON Corporation. DirectDrive is a registered trademark of Maxim Integrated Products, Inc. Dolby is a registered trademark of Dolby Laboratories.
Legal notices Trademark information Trademark information (continued) QSPI is a trademark of Motorola, Inc. SD is a trademark of the SD Card Association. SMBus is a trademark of Intel Corporation. SPI is a trademark of Motorola, Inc. The PROFI BUS PROCESS FIELD BUS logo is a registered trademark of PROFIBUS and PROFINET International (PI). UCSP is a trademark of Maxim Integrated Products, Inc. UL is a registered trademark of Underwriters Laboratory, Inc.
www.digikey.com/maxim-industrial Innovation Delivered is a trademark and Maxim is a registered trademark of Maxim Integrated Products, Inc. © 2010 Maxim Integrated Products, Inc. All rights reserved.
