DUAL ULTRA MICROPOWER RAIL-TO-RAIL CMOS OPERATIONAL AMPLIFIER

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1 ADVANCED LINEAR DEVICES, INC. ALD276A/ALD276B ALD276 DUAL ULTRA MICROPOWER RAILTORAIL CMOS OPERATIONAL AMPLIFIER GENERAL DESCRIPTION The ALD276 is a dual monolithic CMOS micropower high slewrate operational amplifier intended for a broad range of analog applications using ±1V to ±6V dual power supply systems, as well as 2V to 12V battery operated systems. All device characteristics are specified for 5V single supply or ±2.5V dual supply systems. Supply current is 8µA maximum at 5V supply voltage. It is manufactured with Advanced Linear Devices' enhanced A CMOS silicon gate CMOS process. The ALD276 is designed to offer a tradeoff of performance parameters providing a wide range of desired specifications. It offers the popular industry standard pin configuration. The ALD276 has been developed specifically for the 5V single supply or ±1V to ±6V dual supply user. Several important characteristics of the device make application easier to implement at those voltages. First, each operational amplifier can operate with rail to rail input and output voltages. This means the signal input voltage and output voltage can be equal to the positive and negative supply voltages. This feature allows numerous analog serial stages and flexibility in input signal bias levels. Secondly, each device was designed to accommodate mixed applications where digital and analog circuits may operate off the same power supply or battery. Thirdly, the output stage can typically drive up to 25pF capacitive and 2KΩ resistive loads. These features, combined with extremely low input currents, high open loop voltage gain of 1V/mV, useful bandwidth of 2KHz, a slew rate of.1v/µs, low offset voltage and temperature drift, make the ALD276 a versatile, micropower dual operational amplifier. A typical ALD276 has the capacity to process a.998v amplitude analog signal with only 1.V single supply voltage, while requiring only.1pa input bias current. FEATURES Typical 2µA supply current per amplifier All parameters specified for 5V single supply or ±2.5V dual supply systems Railtorail input and output voltage ranges Unity gain stable Extremely low input bias currents.1pa High source impedance applications Dual power supply ±1.V to ±6.V Single power supply 2V to 12V High voltage gain Unity gain bandwidth of.2mhz Slew rate of.1v/µs Symmetrical output drive APPLICATIONS Voltage follower/buffer/amplifier Charge integrator Photodiode amplifier Data acquisition systems High performance portable instruments Signal conditioning circuits Sensor and transducer amplifiers Low leakage amplifiers Active filters Sample/Hold amplifier Picoammeter Current to voltage converter PIN CONFIGURATION OUT A IN A V OUT B ORDERING INFORMATION Operating Temperature Range 55 C to 125 C C to 7 C C to 7 C 8Pin 8Pin 8Pin CERDIP Small Outline Plastic Dip Package (SOIC) Package ALD276A DA ALD276A SA ALD276A PA ALD276B DA ALD276B SA ALD276B PA ALD276 DA ALD276 SA ALD276 PA IN A V 3 4 TOP VIEW DA, PA, SA PACKAGE 6 5 IN B IN B * Contact factory for industrial temperature range 1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California Tel: (48) Fax: (48) This datasheet has been downloaded from at this page

2 ABSOLUTE MAXIMUM RATINGS Supply voltage, V 13.2V Differential input voltage range.3v to V.3V Power dissipation 6 mw Operating temperature range PA,SA package C to 7 C DA package 55 C to 125 C Storage temperature range 65 C to 15 C Lead temperature, 1 seconds 26 C OPERATING ELECTRICAL CHARACTERISTICS unless otherwise specified 276A 276B 276 Test Supply V S ±1. ±6. ±1. ±6. ±1. ±6. V Dual Supply Voltage V V Single Supply Input Offset V OS mv R S Ω Voltage mv C T A 7 C Input Offset I OS pa Current pa C T A 7 C Input Bias I B pa Current pa C T A 7 C Input Voltage V IR V V = 5 Range V Input Resistance R IN Ω Input Offset Voltage Drift TCV OS µv/ C R S Ω Power Supply PSRR db R S Ω Rejection Ratio db C T A 7 C Common Mode CMRR db R S Ω Rejection Ratio db C T A 7 C Large Signal A V V/mV R L = Ω Voltage Gain V/mV R L 1MΩ V/mV R L = Ω C T A 7 C Output V O low V R L = 1MΩ V = 5V Voltage V O high V C T A 7 C Range V O low V R L = Ω V O high V C T A 7 C Output Short Circuit Current I SC µa Supply Current I S µa V IN =V No Load Power Both amplifiers Dissipation P D µw ALD276A/ALD276B Advanced Linear Devices 2 ALD276

3 OPERATING ELECTRICAL CHARACTERISTICS (cont'd) unless otherwise specified 276A 276B 276 Test Input Capacitance C IN pf Bandwidth B W KHz Slew Rate S R V/µs A V = 1 R L = Ω Rise time t r µs R L = Ω Overshoot % R L = Ω Factor Settling µs.1% Time t s A V = 1 R L = Ω Channel Separation C S db A V = 1 TA = 25 C VS = ±1.V unless otherwise specified 276A 276B 276 Test Power Supply Rejection Ratio PSRR db R S 1MΩ Common Mode Rejection Ratio CMRR db R S 1MΩ Large Signal Voltage Gain A V V/mV R L = 1MΩ Output Voltage V O low V R L = 1MΩ Range V O high V Bandwidth B W MHz Slew Rate S R V/µs A V =1 VS = ± 2.5V 55 C TA 125 C unless otherwise specified 276A DA 276B DA 276 DA Test Input Offset Voltage V OS mv R S Ω Input Offset Current I OS na Input Bias Current I B na Power Supply Rejection Ratio PSRR db R S 1MΩ Common Mode Rejection Ratio CMRR db R S 1MΩ Large Signal Voltage Gain A V V/mV R L = 1MΩ Output Voltage V O low V Range V O high V R L = 1MΩ ALD276A/ALD276B Advanced Linear Devices 3 ALD276

4 Design & Operating Notes: 1. The ALD276 CMOS operational amplifier uses a 3 gain stage architecture and an improved frequency compensation scheme to achieve large voltage gain, high output driving capability, and better frequency stability. In a conventional CMOS operational amplifier design, compensation is achieved with a pole splitting capacitor together with a nulling resistor. This method is, however, very bias dependent and thus cannot accommodate the large range of supply voltage operation as is required from a stand alone CMOS operational amplifier. The ALD276 is internally compensated for unity gain stability using a novel scheme that does not use a nulling resistor. This scheme produces a clean single pole roll off in the gain characteristics while providing for more than 7 degrees of phase margin at the unity gain frequency. 2. The ALD276 has complementary pchannel and nchannel input differential stages connected in parallel to accomplish rail to rail input common mode voltage range. This means that with the ranges of common mode input voltage close to the power supplies, one of the two differential stages is switched off internally. To maintain compatibility with other operational amplifiers, this switching point has been selected to be about 1.5V below the positive supply voltage. Since offset voltage trimming on the ALD276 is made when the input voltage is symmetrical to the supply voltages, this internal switching does not affect a large variety of applications such as an inverting amplifier or noninverting amplifier with a gain larger than 2.5 (5V operation), where the common mode voltage does not make excursions above this switching point. The user should however, be aware that this switching does take place if the operational amplifier is connected as a unity gain buffer and should make provision in his design to allow for input offset voltage variations. 3. The input bias and offset currents are essentially input protection diode reverse bias leakage currents, and are typically less than 1pA at room temperature. This low input bias current assures that the analog signal from the source will not be distorted by input bias currents. Normally, this extremely high input impedance of greater than 1 12 Ω would not be a problem as the source impedance would limit the node impedance. However, for applications where source impedance is very high, it may be necessary to limit noise and hum pickup through proper shielding. 4. The output stage consists of class AB complementary output drivers, capable of driving a low resistance load. The output voltage swing is limited by the drain to source onresistance of the output transistors as determined by the bias circuitry, and the value of the load resistor. When connected in the voltage follower configuration, the oscillation resistant feature, combined with the rail to rail input and output feature, makes an effective analog signal buffer for medium to high source impedance sensors, transducers, and other circuit networks. 5. The ALD276 operational amplifier has been designed to provide full static discharge protection. Internally, the design has been carefully implemented to minimize latch up. However, care must be exercised when handling the device to avoid strong static fields that may degrade a diode junction, causing increased input leakage currents. In using the operational amplifier, the user is advised to power up the circuit before, or simultaneously with, any input voltages applied and to limit input voltages to not exceed.3v of the power supply voltage levels. 6. The ALD276, with its micropower operation, offers numerous benefits in reduced power supply requirements, less noise coupling and current spikes, less thermally induced drift, better overall reliability due to lower self heating, and lower input bias current. It requires practically no warm up time as the chip junction heats up to only.1 C above ambient temperature under most operating conditions. TYPICAL PERFORMANCE CHARACTERISTICS SUPPLY CURRENT (µa) SUPPLY CURRENT AS A FUNCTION OF SUPPLY VOLTAGE INPUTS GROUNDED OUTPUT UNLOADED T A = 55 C 25 C 25 C 4 7 C 125 C ±1 ±2 ±3 ±4 ±5 ±6 COMMON MODE INPUT VOLTAGE RANGE (V) ±7 ±6 ±5 ±4 ±3 ±2 ±1 COMMON MODE INPUT VOLTAGE RANGE AS A FUNCTION OF SUPPLY VOLTAGE ±1 ±2 ±3 ±4 ±5 ±6 ±7 OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF LOAD RESISTANCE INPUT BIAS CURRENT AS A FUNCTION OF AMBIENT TEMPERATURE 1 1 OPEN LOOP VOLTAGE GAIN (V/mV) K 1M LOAD RESISTANCE (Ω) INPUT BIAS CURRENT (pa) AMBIENT TEMPERATURE ( C) ALD276A/ALD276B Advanced Linear Devices 4 ALD276

5 TYPICAL PERFORMANCE CHARACTERISTICS OPEN LOOP VOLTAGE GAIN (V/mV) 1 1 OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF SUPPLY VOLTAGE AND TEMPERATURE 1 ±55 C T A 125 C R L = Ω 1 ±2 ±4 ±6 ±8 OUTPUT VOLTAGE SWING (V) ±6 ±5 ±4 ±3 ±2 OUTPUT VOLTAGE SWING AS A FUNCTION OF SUPPLY VOLTAGE ±25 C T A 125 C R L = Ω ±1 ±1 ±2 ±3 ±4 ±5 ±6 ±7 INPUT OFFSET VOLTAGE (mv) INPUT OFFSET VOLTAGE AS A FUNCTION OF AMBIENT TEMPERATURE REPRESENTATIVE UNITS AMBIENT TEMPERATURE ( C) OPEN LOOP VOLTAGE GAIN (db) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF FREQUENCY K 1K 1M FREQUENCY (Hz) PHASE SHIFT IN DEGREES INPUT OFFSET VOLTAGE (mv) INPUT OFFSET VOLTAGE AS A FUNCTION OF COMMON MODE INPUT VOLTAGE COMMON MODE INPUT VOLTAGE (V) 2V/div LARGE SIGNAL TRANSIENT RESPONSE 5mV/div V S = ±1.V R L = Ω 1µs/div LARGE SIGNAL TRANSIENT RESPONSE SMALL SIGNAL TRANSIENT RESPONSE 5V/div R L = Ω 1mV/div R L = Ω 2V/div 1µs/div 5mV/div 1µs/div ALD276A/ALD276B Advanced Linear Devices 5 ALD276

6 TYPICAL APPLICATIONS RAILTORAIL VOLTAGE FOLLOWER/BUFFER RAILTORAIL WAVEFORM Z IN = ~ 1 12 Ω V IN V IN 5V 5V OUTPUT * See Rail to Rail Waveform 5V INPUT V 5V OUTPUT V Performance waveforms. Upper trace is the output of a Wien Bridge Oscillator. Lower trace is the output of RailtoRail voltage follower. HIGH INPUT IMPEDANCE RAILTORAIL PRECISION DC SUMMING AMPLIFIER V 1 V 2 V 3 V 4 = V 1 V 2 V 3 V 4 V = 2.5V V = 2.5V V V R IN = Ω Accuracy limited by resistor tolerances and input offset voltage RAILTORAIL WINDOW COMPARATOR 5V 8 V REF (HIGH) 3 1 1/4 74 C 2 V IN 5 7 V REF (LOW) 6 4 (LOW) FOR VREF (LOW) < V IN < VREF(HIGH) PHOTO DETECTOR CURRENT TO VOLTAGE CONVERTER HIGH IMPEDANCE NONINVERTING AMPLIFIER R F = 5M 9K PHOTODIODE I 2.5V 2.5V = 1 X RF R L = V IN 1V 1V LOW VOLTAGE INSTRUMENTATION AMPLIFIER V R3 R4 5K V f max = 2KHz 4mV V IN 4mV R1 5K V 1M R2 V = 1.V V = 1.V V V All resistors are 1%. V 1M V V = V IN ( 1 2R2 ) (R4) R1 R3 = 25 V IN ALD276A/ALD276B Advanced Linear Devices 6 ALD276

QUAD 5V RAIL-TO-RAIL PRECISION OPERATIONAL AMPLIFIER

QUAD 5V RAIL-TO-RAIL PRECISION OPERATIONAL AMPLIFIER ADVANCED LINEAR DEVICES, INC. ALD472A/ALD472B ALD472 QUAD 5V RAILTORAIL PRECISION OPERATIONAL AMPLIFIER GENERAL DESCRIPTION The ALD472 is a quad monolithic precision CMOS railtorail operational amplifier