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 2010 Microchip Technology Inc. DS21935D-page 1

TCN75A

Features:

• Temperature-to-Digital Converter

•Accuracy:

- ±1 (typical) from -40°C to +125°C

- ±2°C (maximum) from -40°C to +125°C

• User-selectable Resolution: 0.5°C to 0.0625°C

• Operating Voltage Range: 2.7V to 5.5V

• 2-wire Interface: I

C™ Compatible

• Operating Current: 200 µA (typical)

• Shutdown Current: 2 µA (maximum)

• Power-saving One-shot Temperature

Measurement

• Available Packages: MSOP-8, SOIC-8

Typical Applications:

• Personal Computers and Servers

• Hard Disk Drives and Other PC Peripherals

• Entertainment Systems

• Office Equipment

• Data Communication Equipment

• General Purpose Temperature Monitoring

Typical Application

Description:

Microchip Technology Inc.’s TCN75A digital tempera-

ture sensor converts temperatures between -40°C and

+125°C to a digital word, with ±1°C (typical) accuracy.

The TCN75A product comes with user-programmable

registers that provide flexibility for temperature-sensing

applications. The register settings allow

user-selectable, 0.5°C to 0.0625°C temperature

measurement resolution, configuration of the

power-saving Shutdown and One-shot (single

conversion on command while in Shutdown) modes

and the specification of both temperature alert output

and hysteresis limits. When the temperature changes

beyond the specified limits, the TCN75A outputs an

alert signal. The user has the option of setting the alert

output signal polarity as an active-low or active-high

comparator output for thermostat operation, or as

temperature event interrupt output for

microprocessor-based systems.

This sensor has an industry standard 2-wire, I

C™

compatible serial interface, allowing up to eight devices

to be controlled in a single serial bus. These features

make the TCN75A ideal for low-cost, sophisticated

multi-zone temperature-monitoring applications.

Package Types

TCN75A

SDA

SCL

I/O Ports

PULL-UP

PIC

SDA

GND

ALERT

SCL

Microcontroller

ALERT

SDA

GND

ALERT

SCL

8-Pin SOIC, MSOP

TCN75A

2-Wire Serial Temperature Sensor

Summary of content (40 pages)

PAGE 1
TCN75A 2-Wire Serial Temperature Sensor Features: Description: • Temperature-to-Digital Converter • Accuracy: - ±1 (typical) from -40°C to +125°C - ±2°C (maximum) from -40°C to +125°C • User-selectable Resolution: 0.5°C to 0.0625°C • Operating Voltage Range: 2.7V to 5.5V • 2-wire Interface: I2C™ Compatible • Operating Current: 200 µA (typical) • Shutdown Current: 2 µA (maximum) • Power-saving One-shot Temperature Measurement • Available Packages: MSOP-8, SOIC-8 Microchip Technology Inc.
PAGE 2
TCN75A NOTES: DS21935D-page 2  2010 Microchip Technology Inc.
PAGE 3
TCN75A 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings † VDD....................................................................... 6.0V †Notice: Stresses above those listed under “Maximum ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied.
PAGE 4
TCN75A DIGITAL INPUT/OUTPUT PIN CHARACTERISTICS Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground and TA = -40°C to +125°C. Parameters Sym Min Typ Max Units Conditions VIH 0.7 VDD — — V Low-level Voltage VIL — — 0.3 VDD V Input Current IIN -1 — +1 µA Low-level Voltage VOL — — 0.4 V IOL= 3 mA High-level Current IOH — — 1 µA VOH = 5V Low-level Current IOL 6 — — mA VOL = 0.6V CIN — 10 — pF VHYST 0.
PAGE 5
TCN75A SERIAL INTERFACE TIMING SPECIFICATIONS (Note 1) Electrical Specifications: Unless otherwise indicated, VDD = 2.7V to 5.5V, GND = Ground, TA = -40°C to +125°C, CL = 80 pF and all limits measured to 50% point. Parameters 2-Wire Sym Min Typ Max Units Conditions I2 C™ Compatible Interface Serial Port Frequency fSC 0 — 400 kHz Clock Period tSC 2.5 — — µs Low Clock tLOW 1.3 — — µs High Clock tHIGH 0.
PAGE 6
TCN75A NOTES: DS21935D-page 6  2010 Microchip Technology Inc.
PAGE 7
TCN75A 2.0 TYPICAL PERFORMANCE CURVES The graphs and tables provided following this note are a statistical summary based on a limited number of samples and are provided for informational purposes only. The performance characteristics listed herein are not tested or guaranteed. In some graphs or tables, the data presented may be outside the specified operating range (e.g., outside specified power supply range) and therefore outside the warranted range. Note: Note: Unless otherwise noted: VDD = 2.7V to 5.
PAGE 8
TCN75A Note: Unless otherwise noted: VDD = 2.7V to 5.5V. 145 VOL = 0.6V 42 VDD = 5.5V VDD = 3.3V VDD = 2.7V 36 30 24 18 12 Temperature Data (°C) ALERT and SDA I OL (mA) 48 Average of 10 samples per package 125 105 85 65 SOIC 45 MSOP 25 27°C (Air) to 125°C (Oil bath) 6 5 -55 -35 -15 5 25 45 TA (°C) 65 85 105 125 FIGURE 2-7: ALERT and SDA IOL vs. Ambient Temperature. -2 0 FIGURE 2-9: vs. Time. 2 4 6 8 10 12 14 16 18 20 Time (s) TCN75A Thermal Response ALERT and SDA V OL (V) 0.
PAGE 9
TCN75A 3.0 PIN DESCRIPTION The descriptions of the pins are listed in Table 3-1. TABLE 3-1: 3.
PAGE 10
TCN75A NOTES: DS21935D-page 10  2010 Microchip Technology Inc.
PAGE 11
TCN75A 4.0 SERIAL COMMUNICATION 4.1.1 4.1 2-Wire SMBus/Standard Mode I2C™ Protocol-Compatible Interface Data transfers are initiated by a Start condition (Start), followed by a 7-bit device address and a read/write bit. An Acknowledge (ACK) from the slave confirms the reception of each byte. Each access must be terminated by a Stop condition (Stop).
PAGE 12
TCN75A 4.1.6 Address Byte 1 SCL SDA 2 1 0 3 4 5 6 7 8 A C K 1 A2 A1 A0 0 9 Start Address Code Slave Address R/W TCN75A Response FIGURE 4-1: 4.1.5 Device Addressing. DATA VALID After the Start condition, each bit of data in transmission needs to be settled for a time specified by tSU-DATA before SCL toggles from low-to-high (see “Serial Interface Timing Specifications (Note 1)”.
PAGE 13
TCN75A 5.0 FUNCTIONAL DESCRIPTION The TCN75A temperature sensor consists of a bandgap type temperature sensor, a  Analog-to-Digital Converter (ADC), user-programmable registers and a 2-wire I2C protocol-compatible serial interface. Resolution 5.1 Temperature Sensor The TCN75A uses the difference in the base-emitter voltage of a transistor while its collector current is changed from IC1 to IC2.
PAGE 14
TCN75A 5.3 Registers Resolution The TCN75A has four registers that are user-accessible. These registers are specified as the Ambient Temperature (TA) register, the Temperature Limit-set (TSET) register, the Temperature Hysteresis (THYST) register and device Configuration (CONFIG) register. One-Shot Shutdown Fault Queue The Ambient Temperature register is a read-only register and is used to access the ambient temperature data. The data from the ADC is loaded in parallel in the register.
PAGE 15
TCN75A TABLE 5-1: Register Pointer P1 P0 MSB/ LSB BIT ASSIGNMENT SUMMARY FOR ALL REGISTERS Bit Assignment 7 Ambient Temperature Register (TA) 00 6 5 4 3 2 1 0 MSB Sign 26°C 25°C 24°C 23°C 22°C 21°C 20°C LSB 2-1°C 2-2°C 2-3°C 2-4°C 0 0 0 0 ALERT Polarity COMP/INT Shutdown Sensor Configuration Register (CONFIG) 01 LSB One-Shot Resolution Temperature Hysteresis Register (THYST) 10 MSB Sign 26°C 25°C 24°C 23°C 22°C 21°C 20°C LSB 2-1°C 0 0 0 0 0 0 0 Temperat
PAGE 16
TCN75A 5.3.1 AMBIENT TEMPERATURE REGISTER (TA) EQUATION 5-2: The TCN75A has a 16-bit read-only Ambient Temperature register that contains 9-bit to 12-bit temperature data. (0.5°C to 0.0625°C resolutions, respectively). This data is formatted in two’s complement. The bit assignments, as well as the corresponding resolution, is shown in the register assignment below.
PAGE 17
TCN75A 1 2 3 4 5 6 7 8 1 2 3 4 5 6 7 8 SDA It is not necessary to select the Register Pointer if it was set from the previous read/ write. (see Section 4.1.
PAGE 18
TCN75A 5.3.2 SENSOR CONFIGURATION REGISTER (CONFIG) The TCN75A has an 8-bit read/write Configuration register that allows the user to select the different features. These features include shutdown, ALERT output select as comparator or interrupt output, ALERT output polarity, fault queue cycle, temperature measurement resolution and One-shot mode (single conversion while in shutdown). These functions are described in detail in the following sections.
PAGE 19
TCN75A • Writing to the CONFIG Register to change the resolution to 0.0625°C <0110 0000>b. 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C 1 2 3 4 5 6 7 8 0 0 0 0 0 0 0 1 SCL SDA S A K Address Byte A C K CONFIG Pointer TCN75A TCN75A 1 2 3 4 5 6 7 8 0 1 1 0 0 0 0 0 1 A C K P MSB Data TCN75A • Reading the CONFIG Register.
PAGE 20
TCN75A 5.3.3 TEMPERATURE HYSTERESIS REGISTER (THYST) The TCN75A has a 16-bit read/write Temperature Hysteresis register that contains a 9-bit data in two’s compliment format. This register is used to set a hysteresis for the TSET limit. Therefore, the data represents a minimum temperature limit. If the ambient temperature drifts below the specified limit, the TCN75A asserts an alert output (refer to Section 5.3.4.3 “ALERT Output Configuration”).
PAGE 21
TCN75A • Writing to the THYST Register to set the temperature hysteresis to 95°C <0101 1111 0000 0000>b. 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C 1 2 3 4 5 6 7 8 0 0 0 0 0 0 1 0 SCL SDA S A K Address Byte A C K THYST Pointer TCN75A TCN75A 1 2 3 4 5 6 7 8 0 1 0 1 1 1 1 1 A C K 1 2 3 4 5 6 7 8 0 0 0 0 0 0 0 0 MSB Data A C K P LSB Data TCN75A TCN75A • Reading the THYST Register.
PAGE 22
TCN75A 5.3.4 TEMPERATURE LIMIT-SET REGISTER (TSET) The TCN75A has a 16-bit read/write Temperature Limit-Set register (TSET) which contains a 9-bit data in two’s compliment format. This data represents a maximum temperature limit. If the ambient temperature exceeds this specified limit, the TCN75A asserts an alert output. (Refer to Section 5.3.4.3 “ALERT Output Configuration”). This register uses the nine Most Significant bits (MSbs) and all other bits are “don’t cares”.
PAGE 23
TCN75A • Writing to the TSET Register to set the temperature limit to 90°C, <0101 1010 0000 0000>b 1 2 3 4 5 6 7 8 1 0 0 1 A 2 A 1 A 0 W C 1 2 3 4 5 6 7 8 0 0 0 0 0 0 1 1 SCL SDA S A K Address Byte A C K TSET Pointer TCN75A TCN75A 1 2 3 4 5 6 7 8 0 1 0 1 1 0 1 0 A C K 1 2 3 4 5 6 7 8 0 0 0 0 0 0 0 0 MSB Data A C K P LSB Data TCN75A TCN75A • Reading the TSET Register.
PAGE 24
TCN75A 5.3.4.1 5.3.4.3 Shutdown Mode The Shutdown mode disables all power-consuming activities (including temperature sampling operations) while leaving the serial interface active. The device consumes 2 µA (maximum) in this mode. It remains in this mode until the Configuration register is updated to enable continuous conversion or until power is recycled.
PAGE 25
TCN75A FIGURE 5-7: 5.3.4.6 Alert Output. 5.4 Fault Queue The fault queue feature can be used as a filter to lessen the probability of spurious activation of the ALERT pin. TA must remain above TSET for the consecutive number of conversion cycles selected using the Fault Queue bits. Bit 3 and bit 4 of the CONFIG register can be used to select up to six fault queue cycles.
PAGE 26
TCN75A NOTES: DS21935D-page 26  2010 Microchip Technology Inc.
PAGE 27
TCN75A 6.0 APPLICATIONS INFORMATION 6.1 Connecting to the Serial Bus The SDA and SCL serial interface are open-drain pins that require pull-up resistors. This configuration is shown in Figure 6-1. VDD R R SDA SCL PIC® MCU FIGURE 6-1: Interface. TCN75A Pull-up Resistors On Serial The TCN75A is designed to meet 0.4V (maximum) voltage drop at 3 mA of current. This allows the TCN75A to drive lower values of pull-up resistors and higher bus capacitance.
PAGE 28
TCN75A NOTES: DS21935D-page 28  2010 Microchip Technology Inc.
PAGE 29
TCN75A 7.0 PACKAGING INFORMATION 7.1 Package Marking Information Example: 8-Lead MSOP XXXXX YWWNNN N75A/E 018256 8-Lead SOIC (150 mil) XXXXXXXX XXXXYYWW NNN Legend: XX...X Y YY WW NNN e3 * Note: Example: TCN75AV e3 OA^^1018 256 Customer-specific information Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week ‘01’) Alphanumeric traceability code Pb-free JEDEC designator for Matte Tin (Sn) This package is Pb-free.
PAGE 30
TCN75A 1 % & % ! % 2 %% 033))) & &3 " ) 2 ' % 2 $ % % " % D N E E1 NOTE 1 1 2 e b A2 A c φ L L1 A1 4 % & 5 & % 6!&( $ 55 * * 6 6 :+ . / 7 ; % 2 % " $$ 7 = "% " " 2 7 5 % 8 9 % " " 2 67 < < + 9+ + < + * = "% . / * , .
PAGE 31
TCN75A 8-Lead Plastic Micro Small Outline Package (UA) [MSOP] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging  2010 Microchip Technology Inc.
PAGE 32
TCN75A Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS21935D-page 32  2010 Microchip Technology Inc.
PAGE 33
TCN75A Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging  2010 Microchip Technology Inc.
PAGE 34
TCN75A ! "# $%&' ( ) *+ 1 % & % ! % 2 %% 033))) & &3 DS21935D-page 34 " ) 2 ' % 2 $ % % " %  2010 Microchip Technology Inc.
PAGE 35
TCN75A APPENDIX A: REVISION HISTORY Revision D (September 2010) The following is the list of modifications: 1. Updated Section 6.3 Layout Considerations. Revision C (November 2006) The following is the list of modifications: 1. 2. 3. 4. 5. Updated the accuracy specification limits. Numerous edits throughout the data sheet. Updated the package outline drawings. Added disclaimers to package outline drawings. Updated the package marking information for pb-free markings.
PAGE 36
TCN75A NOTES: DS21935D-page 36  2010 Microchip Technology Inc.
PAGE 37
TCN75A PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. X /XX Device Temperature Range Package Device: TCN75A: Temperature Sensor Temperature Range: V Package: OA OA713 = = UA UA713 = = = -40C to +125C Examples: a) b) TCN75AVOA: TCN75AVOA713: 8LD SOIC package. Tape and Reel, 8LD SOIC package. a) b) TCN75AVUA: TCN75AVUA713: 8LD MSOP package. Tape and Reel, 8LD MSOP package.
PAGE 38
TCN75A NOTES: DS21935D-page 38  2010 Microchip Technology Inc.
PAGE 39
Note the following details of the code protection feature on Microchip devices: • Microchip products meet the specification contained in their particular Microchip Data Sheet. • Microchip believes that its family of products is one of the most secure families of its kind on the market today, when used in the intended manner and under normal conditions. • There are dishonest and possibly illegal methods used to breach the code protection feature.
PAGE 40
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