ADVANCED LINEAR DEVICES, INC. ALD2706A/ALD2706B ALD2706 DUAL ULTRA MICROPOWER RAIL-TO-RAIL CMOS OPERATIONAL AMPLIFIER GENERAL DESCRIPTION FEATURES The ALD2706 is a dual monolithic CMOS micropower high slew-rate 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 80µA maximum at 5V supply voltage. It is manufactured with Advanced Linear Devices' enhanced A CMOS silicon gate CMOS process. • Typical 20µA supply current per amplifier • All parameters specified for +5V single supply or ±2.5V dual supply systems • Rail-to-rail input and output voltage ranges • Unity gain stable • Extremely low input bias currents -- 0.1pA • High source impedance applications • Dual power supply ±1.0V to ±6.0V • Single power supply +2V to +12V • High voltage gain • Unity gain bandwidth of 0.2MHz • Slew rate of 0.1V/µs • Symmetrical output drive The ALD2706 is designed to offer a trade-off of performance parameters providing a wide range of desired specifications. It offers the popular industry standard pin configuration. The ALD2706 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 20KΩ resistive loads. These features, combined with extremely low input currents, high open loop voltage gain of 100V/mV, useful bandwidth of 200KHz, a slew rate of 0.1V/µs, low offset voltage and temperature drift, make the ALD2706 a versatile, micropower dual operational amplifier. A typical ALD2706 has the capacity to process a 0.998V amplitude analog signal with only 1.000V single supply voltage, while requiring only 0.1pA input bias current. 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 ORDERING INFORMATION Operating Temperature Range -55°C to +125°C 0°C to +70°C 0°C to +70°C 8-Pin CERDIP 8-Pin Small Outline Package (SOIC) 8-Pin Plastic Dip Package ALD2706A DA ALD2706B DA ALD2706 DA ALD2706A SA ALD2706B SA ALD2706 SA ALD2706A PA ALD2706B PA ALD2706 PA OUT A 1 8 V+ -IN A 2 7 OUT B +IN A 3 6 -IN B V- 4 5 +IN B TOP VIEW DA, PA, SA PACKAGE * Contact factory for industrial temperature range © 1998 Advanced Linear Devices, Inc. 415 Tasman Drive, Sunnyvale, California 94089 -1706 Tel: (408) 747-1155 Fax: (408) 747-1286 http://www.aldinc.com ABSOLUTE MAXIMUM RATINGS Supply voltage, V+ Differential input voltage range Power dissipation Operating temperature range PA,SA package DA package Storage temperature range Lead temperature, 10 seconds 13.2V -0.3V to V + +0.3V 600 mW 0°C to +70°C -55°C to +125°C -65°C to +150°C +260°C OPERATING ELECTRICAL CHARACTERISTICS TA = 25 °C VS = ±2.5V unless otherwise specified Min 2706B Typ Max Min ±6.0 ±1.0 12.0 2.0 ±6.0 12.0 ±1.0 2.0 Symbol Supply Voltage VS V+ Input Offset Voltage VOS Input Offset Current IOS 0.1 20 200 0.1 20 200 Input Bias Current IB 0.1 20 200 0.1 20 200 Input Voltage Range VIR Input Resistance RIN Input Offset Voltage Drift TCVOS Min 2706A Typ Parameter ±1.0 2.0 Max 2.0 2.8 -0.3 -2.8 5.3 2.8 2706 Typ Max Unit Test Conditions ±6.0 12.0 V V Dual Supply Single Supply 10.0 11.0 mV mV RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C 0.1 20 200 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C 0.1 20 200 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C 5.3 2.8 V V V+ = +5 VS = ±2.5V 5.0 5.8 -0.3 -2.8 5.3 2.8 -0.3 -2.8 Ω 10 12 1012 1012 7 7 10 µV/°C RS ≤ 100KΩ Power Supply Rejection Ratio PSRR 65 65 80 80 65 65 80 80 60 60 80 80 dB dB R S ≤ 100KΩ 0°C ≤ TA ≤ +70°C Common Mode Rejection Ratio CMRR 65 65 83 83 65 65 83 83 60 60 83 83 dB dB RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C Large Signal Voltage Gain AV 10 100 300 10 100 300 5 80 300 V/mV V/mV V/mV RL = 100KΩ RL ≥ 1MΩ RL = 100KΩ 0°C ≤ TA ≤ +70°C 10 Output Voltage Range VO low VO high 0.001 4.999 0.01 4.99 VO low VO high -2.40 2.40 -2.25 2.25 Output Short Circuit Current ISC Supply Current IS Power Dissipation PD ALD2706A/ALD2706B ALD2706 10 50 0.001 4.99 4.999 0.01 V V R L = 1MΩ V+ = +5V 0°C ≤ TA ≤ +70°C -2.40 -2.25 -2.40 2.40 2.25 2.40 -2.25 V V R L = 100KΩ 0°C ≤ TA ≤ +70°C 0.001 4.99 4.999 2.25 200 5 0.01 200 80 400 50 µA 200 80 400 Advanced Linear Devices 50 80 400 µA µW VIN=0V No Load Both amplifiers VS = ±2.5V 2 OPERATING ELECTRICAL CHARACTERISTICS (cont'd) TA = 25 °C VS = ±2.5V unless otherwise specified Symbol Min 2706A Typ 1 1 Bandwidth BW 200 200 200 KHz Slew Rate SR 0.1 0.1 0.1 V/µs AV = +1 RL = 100KΩ Rise time tr 1.0 1.0 1.0 µs RL = 100KΩ 20 20 20 % RL = 100KΩ CL = 25pF 10.0 10.0 10.0 µs 0.1% AV = -1 CL = 25pF RL = 100KΩ 140 140 140 dB AV = 100 ts Channel Separation CS Max Min Max Unit Test Conditions 1 Settling Time Min 2706 Typ CIN Overshoot Factor Max 2706B Typ Parameter Input Capacitance pF TA = 25 °C VS = ±1.0V unless otherwise specified Parameter Symbol Min 2706A Typ Max Min 2706B Typ Max 2706 Typ Min Max Unit Test Conditions Power Supply Rejection Ratio PSRR 80 80 80 dB RS ≤ 1MΩ Common Mode Rejection Ratio CMRR 80 80 80 dB RS ≤ 1MΩ Large Signal Voltage Gain AV 50 50 50 V/mV RL = 1MΩ Output Voltage Range VO low VO high V V RL = 1MΩ Bandwidth BW 0.2 0.2 0.2 MHz Slew Rate SR 0.1 0.1 0.1 V/µs AV =+1 CL = 25pF Unit Conditions RS ≤ 100KΩ 0.9 -0.95 0.95 -0.9 0.9 -.95 0.95 -0.9 -0.95 0.95 0.9 -0.9 VS = ± 2.5V -55°C ≤ TA ≤ +125°C unless otherwise specified 2706A DA Parameter Symbol Min Typ 2706B DA Max Min Typ 2706 DA Max Min Typ Test Max Input Offset Voltage VOS 3.0 6.0 12.0 mV Input Offset Current IOS 4.0 4.0 4.0 nA Input Bias Current IB 4.0 4.0 4.0 nA Power Supply Rejection Ratio PSRR 60 75 60 75 60 75 dB RS ≤ 1MΩ Common Mode Rejection Ratio CMRR 60 83 60 83 60 83 dB RS ≤ 1MΩ Large Signal Voltage Gain AV 10 50 50 5 50 V/mV RL = 1MΩ Output Voltage Range VO low VO high 2.25 -2.40 2.40 -2.40 -2.25 2.40 2.25 -2.40 2.40 V V R L = 1MΩ ALD2706A/ALD2706B ALD2706 10 -2.25 2.25 Advanced Linear Devices -2.25 3 Design & Operating Notes: 1. The ALD2706 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 ALD2706 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 70 degrees of phase margin at the unity gain frequency. 2. The ALD2706 has complementary p-channel and n-channel 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 ALD2706 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 10 12Ω 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 on-resistance 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 ALD2706 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 0.3V of the power supply voltage levels. 6. The ALD2706, 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 0.1°C above ambient temperature under most operating conditions. TYPICAL PERFORMANCE CHARACTERISTICS INPUTS GROUNDED OUTPUT UNLOADED COMMON MODE INPUT VOLTAGE RANGE AS A FUNCTION OF SUPPLY VOLTAGE ±7 +25°C -25°C 160 TA = -55°C 120 80 40 +70°C ±6 COMMON MODE INPUT VOLTAGE RANGE (V) SUPPLY CURRENT (µA) SUPPLY CURRENT AS A FUNCTION OF SUPPLY VOLTAGE +125°C 0 ±5 ±4 ±3 ±2 ±1 0 0 ±1 ±2 ±3 ±4 ±5 ±6 ±2 ±3 ±4 ±5 ±6 ±7 SUPPLY VOLTAGE (V) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF LOAD RESISTANCE INPUT BIAS CURRENT AS A FUNCTION OF AMBIENT TEMPERATURE 10000 10 VS = ±2.5V TA = 25°C INPUT BIAS CURRENT (pA) 100 1 10K ±1 0 SUPPLY VOLTAGE (V) 1000 OPEN LOOP VOLTAGE GAIN (V/mV) TA = 25°C VS = ±2.5V 1000 100 10 1.0 0.1 100K 1M 10M -50 ALD2706A/ALD2706B ALD2706 -25 0 25 50 75 100 125 AMBIENT TEMPERATURE (°C) LOAD RESISTANCE (Ω) Advanced Linear Devices 4 TYPICAL PERFORMANCE CHARACTERISTICS OUTPUT VOLTAGE SWING AS A FUNCTION OF SUPPLY VOLTAGE OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF SUPPLY VOLTAGE AND TEMPERATURE OUTPUT VOLTAGE SWING (V) OPEN LOOP VOLTAGE GAIN (V/mV) 1000 100 10 ±55°C ≤ TA ≤ +125°C RL = 100KΩ ±25°C ≤ TA ≤ +125°C RL = 100KΩ ±5 ±4 ±3 ±2 ±1 1 ±2 0 ±4 ±8 ±6 0 ±1 ±3 ±4 ±5 ±6 SUPPLY VOLTAGE (V) INPUT OFFSET VOLTAGE AS A FUNCTION OF AMBIENT TEMPERATURE REPRESENTATIVE UNITS OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF FREQUENCY ±7 120 +5 +4 OPEN LOOP VOLTAGE GAIN (dB) VS = ±2.5V +3 +2 +1 0 -1 -2 -3 -4 VS = ±2.5V TA = 25°C 100 80 60 0 40 45 20 90 0 135 180 -20 -5 -50 -25 0 +25 +50 +75 +100 +125 1 10 AMBIENT TEMPERATURE (°C) INPUT OFFSET VOLTAGE AS A FUNCTION OF COMMON MODE INPUT VOLTAGE INPUT OFFSET VOLTAGE (mV) ±2 SUPPLY VOLTAGE (V) 100 1K 10K 100K FREQUENCY (Hz) 1M PHASE SHIFT IN DEGREES INPUT OFFSET VOLTAGE (mV) ±6 10M LARGE - SIGNAL TRANSIENT RESPONSE 15 VS = ±2.5V TA = 25°C 10 2V/div VS = ±1.0V TA = 25°C RL = 100KΩ CL= 25pF 500mV/div 10µs/div 5 0 -5 -10 -15 -2 -1 0 +1 +2 +3 COMMON MODE INPUT VOLTAGE (V) LARGE - SIGNAL TRANSIENT RESPONSE 5V/div 2V/div ALD2706A/ALD2706B ALD2706 SMALL - SIGNAL TRANSIENT RESPONSE VS = ±2.5V TA = 25°C RL = 100KΩ CL= 25pF 100mV/div 10µs/div 50mV/div Advanced Linear Devices VS = ±2.5V TA = 25°C RL = 100KΩ CL= 25pF 10µs/div 5 TYPICAL APPLICATIONS RAIL-TO-RAIL VOLTAGE FOLLOWER/BUFFER RAIL-TO-RAIL WAVEFORM INPUT 5V ~ 1012Ω ZIN = +5V 0V 0.1µF - +5V OUTPUT 0V OUTPUT + VIN 1/2 ALD2706 Performance waveforms. Upper trace is the output of a Wien Bridge Oscillator. Lower trace is the output of Rail-to-Rail voltage follower. 0≤ VIN ≤ 5V * See Rail to Rail Waveform RAIL-TO-RAIL WINDOW COMPARATOR HIGH INPUT IMPEDANCE RAIL-TO-RAIL PRECISION DC SUMMING AMPLIFIER +5V 1/2 ALD2706 8 V+ = +2.5V V1 100K VREF (HIGH) 3 + 1 10M + 0.1µF V2 10M 10M 10M 2 VOUT VIN VOUT - 1/4 74 C00 5 0.1µF + 7 V3 V4 V- = - 2.5V 10M 100K V- ≤ VOUT ≤ V+ VREF (LOW) 6 - 4 VOUT = V1 + V2 - V3 - V4 RIN = 10MΩ Accuracy limited by resistor tolerances and input offset voltage VOUT (LOW) FOR VREF (LOW) < VIN < VREF(HIGH) PHOTO DETECTOR CURRENT TO VOLTAGE CONVERTER HIGH IMPEDANCE NON-INVERTING AMPLIFIER 900K 100K RF = 5M I PHOTODIODE 1/2 ALD2706 10M - +2.5V +1V VOUT = 1 X RF VOUT + -2.5V VIN RL = 100K + -1V 1/2 ALD2706 1/2 ALD2706 LOW VOLTAGE INSTRUMENTATION AMPLIFIER 1/2 ALD2706 V+ 0.1µF R3 100K + - R4 500K 100K V- V+ 0.1µF 0.1µF R1 50K f max = 20KHz -40mV ≤ VIN ≤ 40mV + VOUT V+ 1M 1/2 ALD2706 R2 100K - V- 0.1µF V- 100K + 1/2 ALD2706 ALD2706A/ALD2706B ALD2706 1M V+ = +1.0V V- = -1.0V V- ≤ VOUT ≤ V+ All resistors are 1%. Advanced Linear Devices VOUT = VIN ( 1+ 2R2 ) (R4) R1 R3 = 25 VIN 6