User Manual

ManualsBrandsRainbow Electronics ManualsReceivers and AmplifiersMAX495

_______________General Description

The dual MAX492, quad MAX494, and single MAX495

operational amplifiers combine excellent DC accuracy

with rail-to-rail operation at the input and output. Since

the common-mode voltage extends from V

to V

the devices can operate from either a single supply

(+2.7V to +6V) or split supplies (±1.35V to ±3V). Each

op amp requires less than 150µA supply current. Even

with this low current, the op amps are capable of driving

a 1kΩ load, and the input referred voltage noise is only

25nV/√Hz. In addition, these op amps can drive loads in

excess of 1nF.

The precision performance of the MAX492/MAX494/

MAX495, combined with their wide input and output

dynamic range, low-voltage single-supply operation, and

very low supply current, makes them an ideal choice for

battery-operated equipment and other low-voltage appli-

cations. The MAX492/MAX494/MAX495 are available in

DIP and SO packages in the industry-standard op-amp

pin configurations. The MAX495 is also available in the

smallest 8-pin SO: the µMAX package.

________________________Applications

Portable Equipment

Battery-Powered Instruments

Data Acquisition

Signal Conditioning

Low-Voltage Applications

____________________________Features

♦ Low-Voltage Single-Supply Operation (+2.7V to +6V)

♦ Rail-to-Rail Input Common-Mode Voltage Range

♦ Rail-to-Rail Output Swing

♦ 500kHz Gain-Bandwidth Product

♦ Unity-Gain Stable

♦ 150µA Max Quiescent Current per Op Amp

♦ No Phase Reversal for Overdriven Inputs

♦ 200µV Offset Voltage

♦ High Voltage Gain (108dB)

♦ High CMRR (90dB) and PSRR (110dB)

♦ Drives 1kΩ Load

♦ Drives Large Capacitive Loads

♦ MAX495 Available in µMAX Package—8-Pin SO

______________Ordering Information

Ordering Information continued at end of data sheet.

Dice are specified at TA = +25°C, DC parameters only.

MAX492/MAX494/MAX495

Single/Dual/Quad, Micropower,

Single-Supply Rail-to-Rail Op Amps

________________________________________________________________

Maxim Integrated Products

OUT2

IN2-

IN2+

IN1+

IN1-

OUT1

MAX492

DIP/SO

TOP VIEW

N.C.

OUT

NULL

IN1+

IN1-

NULL

MAX495

DIP/SO/µMAX

_________________Pin Configurations

MAX187

(ADC)

GND

INPUT SIGNAL CONDITIONING FOR LOW-VOLTAGE ADC

SERIAL

INTERFACE

4.096V

AIN

DOUT

SCLK

SHDN

REF

ANALOG

INPUT

+5V

10k

MAX495

__________Typical Operating Circuit

For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800

19-0265; Rev 2; 9/96

PART

MAX492CPA

MAX492CSA

MAX492C/D 0°C to +70°C

0°C to +70°C

TEMP. RANGE PIN-PACKAGE

8 Plastic DIP

8 SO

Dice*

MAX492EPA

MAX492ESA -40°C to +85°C

-40°C to +85°C 8 Plastic DIP

8 SO

MAX492MJA -55°C to +125°C 8 CERDIP

Pin Configurations continued at end of data sheet.

Summary of content (16 pages)

PAGE 1
9-0265; Rev 2; 9/96 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps The dual MAX492, quad MAX494, and single MAX495 operational amplifiers combine excellent DC accuracy with rail-to-rail operation at the input and output. Since the common-mode voltage extends from VCC to VEE, the devices can operate from either a single supply (+2.7V to +6V) or split supplies (±1.35V to ±3V). Each op amp requires less than 150µA supply current.
PAGE 2
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps ABSOLUTE MAXIMUM RATINGS Supply Voltage (VCC to VEE) ....................................................7V Common-Mode Input Voltage..........(VCC + 0.3V) to (VEE - 0.3V) Differential Input Voltage .........................................±(VCC - VEE) Input Current (IN+, IN-, NULL1, NULL2) ..........................±10mA Output Short-Circuit Duration ....................
PAGE 3
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps (VCC = 2.7V to 6V, VEE = GND, TA = +25°C, unless otherwise noted.) PARAMETER CONDITIONS MIN TYP MAX UNITS Gain-Bandwidth Product RL = 100kΩ, CL = 100pF 500 kHz Phase Margin RL = 100kΩ, CL = 100pF 60 degrees Gain Margin RL = 100kΩ, CL = 100pF 10 dB Total Harmonic Distortion RL = 10kΩ, CL = 15pF, VOUT = 2Vp-p, AV = +1, f = 1kHz 0.003 % Slew Rate RL = 100kΩ, CL = 15pF 0.20 V/µs Time To 0.
PAGE 4
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps DC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 6V, VEE = GND, VCM = 0V, VOUT = VCC / 2, TA = -40°C to +85°C, unless otherwise noted.) PARAMETER Input Offset Voltage CONDITIONS MIN MAX VCM = VEE to VCC ±950 Input Offset Voltage Tempco ±2 UNITS µV µV/°C Input Bias Current VCM = VEE to VCC ±100 nA Input Offset Current Common-Mode Input Voltage Range Common-Mode Rejection Ratio VCM = VEE to VCC ±8 nA (VEE - 0.
PAGE 5
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps MAX492/MAX494/MAX495 DC ELECTRICAL CHARACTERISTICS (VCC = 2.7V to 6V, VEE = GND, VCM = 0V, VOUT = VCC / 2, TA = -55°C to +125°C, unless otherwise noted.) PARAMETER Input Offset Voltage CONDITIONS MIN TYP VCM = VEE to VCC Input Offset Voltage Tempco MAX UNITS ±1.2 mV ±2 µV/°C Input Bias Current VCM = VEE to VCC ±200 nA Input Offset Current VCM = VEE to VCC ±10 nA Common-Mode Input Voltage Range VEE - 0.05 VCC + 0.
PAGE 6
__________________________________________Typical Operating Characteristics (TA = +25°C, VCC = 5V, VEE = 0V, unless otherwise noted.) GAIN AND PHASE vs. FREQUENCY MAX492-01 80 180 60 80 120 140 60 120 GAIN -60 0 PHASE PSRR (dB) 0 20 PHASE (DEG) GAIN (dB) 0 PHASE 100 60 40 PHASE (DEG) 60 40 GAIN (dB) 180 120 GAIN 20 POWER-SUPPLY REJECTION RATIO vs. FREQUENCY MAX492-02 MAX492-03 GAIN AND PHASE vs.
PAGE 7
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps LARGE-SIGNAL GAIN vs. OUTPUT VOLTAGE 110 100 RL = 100kΩ RL = 1kΩ 80 70 90 RL = 100kΩ RL = 10kΩ RL = 1kΩ 80 70 VCC = +6V RL TO VEE 60 VCC = +2.7V RL TO VEE 60 50 500 600 100 LARGE-SIGNAL GAIN vs. OUTPUT VOLTAGE GAIN (dB) 80 VCC = +6V RL TO VCC 500 600 140 VCC = 2.7V, RL = 1kΩ 100 80 VCC = 6V, RL = 100kΩ 40 20 VCC = 2.
PAGE 8
____________________________Typical Operating Characteristics (continued) (TA = +25°C, VCC = 5V, VEE = 0V, unless otherwise noted.) CURRENT-NOISE DENSITY vs. FREQUENCY VOLTAGE-NOISE DENSITY vs. FREQUENCY CURRENT-NOISE DENSITY (pA/√Hz) 10 INPUT REFERRED MAX492-20 5.0 MAX492-19 4.5 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 INPUT REFERRED 0 1 0.01 1 0.1 0.01 10 10 TOTAL HARMONIC DISTORTION + NOISE vs. PEAK-TO-PEAK SIGNAL AMPLITUDE TOTAL HARMONIC DISTORTION + NOISE vs. FREQUENCY 0.1 MAX492-21 0.
PAGE 9
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps LARGE-SIGNAL TRANSIENT RESPONSE LARGE-SIGNAL TRANSIENT RESPONSE VIN 2V/div VIN 2V/div VOUT 2V/div VOUT 2V/div 50µs/div 50µs/div VCC = +5V, AV = +1, RL = 10kΩ VCC = +5V, AV = -1, RL = 10kΩ ______________________________________________________________Pin Description PIN MAX492 MAX494 MAX495 NAME FUNCTION 1 1 — OUT1 Amplifier 1 Output — — 1, 5 NULL Offset Null Input.
PAGE 10
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps __________Applications Information The dual MAX492, quad MAX494, and single MAX495 op amps combine excellent DC accuracy with rail-torail operation at both input and output. With their precision performance, wide dynamic range at low supply voltages, and very low supply current, these op amps are ideal for battery-operated equipment and other lowvoltage applications.
PAGE 11
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps (Figure 4). The diodes limit the differential voltage applied to the amplifiers’ internal circuitry to no more than VF, where VF is the diodes’ forward-voltage drop (about 0.7V at +25°C). Input bias current for the ICs (±25nA typical) is specified for the small differential input voltages.
PAGE 12
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps in series with IN-, IN+, or both. Series resistors are not recommended for amplifier applications, as they may increase input offsets and decrease amplifier bandwidth. Output Loading and Stability Even with their low quiescent current of less than 150µA per op amp, the MAX492/MAX494/MAX495 are well suited for driving loads up to 1kΩ while maintaining DC accuracy.
PAGE 13
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps To increase stability while driving large capacitive loads, connect a pull-up resistor at the output to decrease the current that the amplifier must source. If the amplifier is made to sink current rather than source, stability is further increased. Frequency stability can be improved by adding an output isolation resistor (RS) to the voltage-follower circuit (Figure 8).
PAGE 14
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps VCC 2V/div VCC 1V/div VOUT 500mV/div 5µs/div Figure 11a. Power-Up Settling Time (VCC = +3V) Because the MAX492/MAX494/MAX495 have excellent stability, no isolation resistor is required, except in the most demanding applications. This is beneficial because an isolation resistor would degrade the lowfrequency performance of the circuit.
PAGE 15
Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps PART TEMP.
PAGE 16
MAX492/MAX494/MAX495 Single/Dual/Quad, Micropower, Single-Supply Rail-to-Rail Op Amps ________________________________________________________Package Information DIM C α A 0.101mm 0.004 in e B A1 L A A1 B C D E e H L α INCHES MAX MIN 0.044 0.036 0.008 0.004 0.014 0.010 0.007 0.005 0.120 0.116 0.120 0.116 0.0256 0.198 0.188 0.026 0.016 6° 0° MILLIMETERS MIN MAX 0.91 1.11 0.10 0.20 0.25 0.36 0.13 0.18 2.95 3.05 2.95 3.05 0.65 4.78 5.03 0.41 0.