e ADVANCED LINEAR DEVICES, INC. TM EPAD EN ® AB LE D ALD1731A/ALD1731 PRECISION MICROPOWER CMOS OPERATIONAL AMPLIFIER GENERAL DESCRIPTION FEATURES & BENEFITS The ALD1731A/ALD1731 is a precision, low cost, monolithic CMOS micropower high slew rate operational amplifier intended for a broad range of analog applications using ±1V to ±5V dual power supply systems, as well as +2V to +10V battery operated systems. All device characteristics are specified for +5V single supply or ±2.5V dual supply systems. Supply current is 250µA maximum at 5V supply voltage. It is manufactured with Advanced Linear Devices' enhanced EPAD® silicon gate CMOS process. • Extremely low input offset voltages -35µV typical • Extremely low input bias currents -0.01pA typical • All parameters specified for +5V single supply or ±2.5V dual supply systems • Rail to rail input and output voltage ranges • No frequency compensation required -unity gain stable • Ideal for high source impedance applications • Dual power supplies ±1.0V to ±5.0V • Single power supply +2.0V to +10.0V • High voltage gain -- typically 100V/mV @ ±2.5V(100dB) • Drive as low as 10KΩ load • Output short circuit protected • Unity gain bandwidth of 0.7MHz • Slew rate of 0.7V/µs • Micropower dissipation • Suitable for rugged, temperature-extreme environments The ALD1731A/ALD1731 features extremely low input power requirements, practically removing any loading effects on high source impedance signal sources such as cpacitive sensors. These devices do not add any significant errors, regardless of what the souce impedance variations may be, thereby improving overall system precision and accuracy. The device is designed to offer the benefits of CMOS technology by providing a wide range of desired specifications. The most important of these specifications is extremely low input bias/offset currents at extremely low input offset voltages. It has been developed specifically for the +5V single supply or ±1V to ±5V dual supply user and offers the popular industry standard pin configuration of µA741 and ICL7611 types. Several additional important characteristics of the device make application easier to implement at those voltages. First, the 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. Second, the device was designed to accommodate mixed applications where digital and analog circuits may operate off the same power supply or battery. Third, the output stage can typically drive up to 50pF capacitive and 10KΩ resistive loads. These features, combined with extremely low input currents, high open loop voltage gain of 100V/mV, useful bandwidth of 700KHz, a slew rate of 0.7V/µs, low power dissipation of 0.5mW, low offset voltage and temperature drift, make the ALD1731A/ALD1731 a versatile, micropower operational amplifier. The ALD1731A/ALD1731, designed and fabricated with silicon gate CMOS technology, offers 0.01pA typical input bias current. On chip offset voltage trimming, using EPAD technology, allows the device to be used without nulling. Additionally, robust design and rigorous screening make this device especially suitable for operation in temperature-extreme environments and rugged conditions. ORDERING INFORMATION (“L” suffix denotes lead-free (RoHS)) 0°C to +70°C Operating Temperature Range 0°C to +70°C -55°C to +125°C 8-Pin Small Outline Package (SOIC) 8-Pin Plastic Dip Package ALD1731ASAL ALD1731SAL ALD1731ASA ALD1731SA ALD1731APAL ALD1731PAL 8-Pin CERDIP Package APPLICATIONS • • • • • • • • • • • • • Voltage amplifier Voltage follower/buffer 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 8 I/C 7 V+ 3 6 OUT 4 5 N/C I/C 1 -IN 2 +IN V- 2 TOP VIEW SAL, PAL, SA, DA PACKAGES ALD1731ADA ALD1731DA * I/C pins are internally connected. Do not connect externally. * Contact factory for leaded (non-RoHS) or high temperature versions. ©2014 Advanced Linear Devices, Inc., Vers. 2.0 www.aldinc.com 1 of 9 ABSOLUTE MAXIMUM RATINGS Supply voltage, V+ Differential input voltage range Power dissipation Operating temperature range SAL, PAL, SA packages DA package Storage temperature range Lead temperature, 10 seconds CAUTION: ESD Sensitive Device. Use static control procedures in ESD controlled environment. 10.6V -0.3V to V+ +0.3V 600mW 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 Parameter Symbol Min ALD1731A Typ Max Supply Voltage VS V+ Input Offset Voltage VOS Input Offset Current IOS 0.01 10 240 Input Bias Current IB 0.01 10 300 Input Voltage Range VIR Input Resistance RIN Input Offset Voltage Drift TCVOS Power Supply Rejection Ratio ±1.0 2.0 ±5.0 10.0 Min ALD1731 Typ +5.3 +2.8 0.4 1.5 mV mV RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C 0.01 10 240 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C 0.01 10 300 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C +5.3 +2.8 V V V+ = +5V VS = ±2.5V -0.3 -2.8 1014 5 5 PSRR 90 90 Common Mode Rejection Ratio CMRR 90 90 Large Signal Voltage Gain AV 100 1000 32 20 Output Voltage Range VO low VO high VO low VO high 4.99 2.40 Ω µV/°C RS ≤ 100KΩ 90 90 dB dB RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C 90 90 dB dB RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C V/mV V/mV V/mV RL = 100KΩ RL = 1MΩ RL = 100KΩ, 0°C ≤ TA ≤ +70°C V V V V RL = 1MΩ, V+ = +5V 0°C ≤ TA ≤ +70°C RL =100KΩ 0°C ≤ TA ≤ +70°C 100 1000 20 0.001 4.999 -2.48 2.48 0.01 4.99 -2.40 2.40 0.001 4.999 -2.48 2.48 0.01 -2.40 Output Short Circuit Current ISC Supply Current IS Power Dissipation PD Input Capacitance CIN 1 1 Bandwidth BW 700 700 KHz Slew Rate SR 0.7 0.7 V/µs ALD1731A/ALD1731 1 120 1 180 120 0.9 Advanced Linear Devices Test Conditions Dual Supply Single Supply ±5.0 10.0 1014 40 Unit V V ±1.0 2.0 0.15 0.8 -0.3 -2.8 Max mA 180 µA VIN = 0V, No Load 0.9 mW VS = ±2.5V pF AV = +1, RL =100KΩ 2 of 9 OPERATING ELECTRICAL CHARACTERISTICS (cont'd) TA = 25°C VS = ±2.5V unless otherwise specified (cont'd) ALD1731A Parameter Symbol Rise time tr Min Overshoot Factor Settling Time ts Typ ALD1731 Max Min Typ Max Unit Test Conditions 0.2 0.2 µs RL = 100KΩ 20 20 % RL = 100KΩ, CL = 50pF 10.0 10.0 µs 0.1%, AV = -1, RL = 100KΩ,2 CL = 25pF TA = 25°C VS = ±5.0V unless otherwise specified ALD1731A Parameter Symbol Min Power Supply Rejection Ratio PSRR 90 Common Mode Rejection Ratio CMRR Large Signal Voltage Gain AV Output Voltage Range VO low VO high 4.90 Typ ALD1731 Unit Test Conditions 90 dB RS ≤ 100KΩ 90 90 dB RS ≤ 100KΩ 250 250 V/mV RL = 100KΩ V RL = 100KΩ -4.98 4.98 Max Min -4.90 4.90 Typ -4.98 4.98 Max -4.90 Bandwidth BW 1.0 1.0 MHz Slew Rate SR 1.0 1.0 V/µs AV = +1, CL = 50pF Max Unit Test Conditions RS ≤ 100KΩ VS = ±2.5V -55°C ≤ TA ≤ +125°C unless otherwise specified ALD1731A Symbol Input Offset Voltage VOS 2.0 3.0 mV Input Offset Current IOS 2.0 2.0 nA Input Bias Current IB 2.0 2.0 nA Power Supply Rejection Ratio PSRR 75 75 dB RS ≤ 100KΩ Common Mode Rejection Ratio CMRR 83 83 dB RS ≤ 100KΩ Large Signal Voltage Gain AV 50 50 V/mV RL = 100KΩ Output Voltage Range VO low VO high V V RL = 100KΩ ALD1731A/ALD1731 Min 2.35 Typ ALD1731 Parameter -2.47 2.45 Max Min -2.40 2.35 Advanced Linear Devices Typ -2.47 2.45 -2.40 3 of 9 Design & Operating Notes: 1. The ALD1731A/ALD1731 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 ALD1731A/ALD1731 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 ALD1731A/ALD1731 has complementary p-channel and nchannel input differential stages connected in parallel to accomplish rail to rail common mode input voltage ranges. 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 ALD1731A/ ALD1731 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 non-inverting amplifier with a gain larger than 2.5 (5V operation), where the common mode voltage does not make excursions below 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 provisions in the 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 0.01pA 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 14Ω 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 ALD1731A/ALD1731 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 not to exceed 0.3V of the power supply voltage levels. 6. The ALD1731A/ALD1731, 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. 7. The ALD1731A/ALD1731 has an internal design architecture that provides robust high temperature operation. Contact factory for custom screening versions. TYPICAL PERFORMANCE CHARACTERISTICS SUPPLY CURRENT AS A FUNCTION OF SUPPLY VOLTAGE ±6 INPUTS GROUNDED OUTPUT UNLOADED +25°C COMMON MODE INPUT VOLTAGE RANGE (V) SUPPLY CURRENT (µA) 500 COMMON MODE INPUT VOLTAGE RANGE AS A FUNCTION OF SUPPLY VOLTAGE 400 -25°C 300 TA = -55°C 200 +125°C 100 +70°C TA = 25°C ±4 ±3 ±2 ±1 0 0 0 ±1 ±2 ±3 ±4 ±5 0 ±6 ±1 ±2 ±3 ±4 ±5 ±6 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF LOAD RESISTANCE INPUT BIAS CURRENT AS A FUNCTION OF AMBIENT TEMPERATURE 1000 INPUT BIAS CURRENT (pA) 1000 OPEN LOOP VOLTAGE GAIN (V/mV) ±5 100 10 VS = ±2.5V TA = 25°C 100 VS = ±2.5V 10 1.0 0.1 0.01 1 10K 100K 1M 10M ALD1731A/ALD1731 -50 -25 0 +25 +50 +75 +100 +125 AMBIENT TEMPERATURE (°C) LOAD RESISTANCE (Ω) Advanced Linear Devices 4 of 9 TYPICAL PERFORMANCE CHARACTERISTICS (cont'd) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF SUPPLY VOLTAGE AND TEMPERATURE OUTPUT VOLTAGE SWING AS A FUNCTION OF SUPPLY VOLTAGE ±6 OUTPUT VOLTAGE SWING (V) OPEN LOOP VOLTAGE GAIN (V/mV) 1000 100 10 -55°C ≤ TA ≤ +125°C RL = 100KΩ -55°C ≤ TA ≤ +125°C RL = 100KΩ ±5 ±4 ±3 ±2 ±1 1 0 ±1 ±2 ±3 ±4 ±5 0 ±6 ±1 ±2 ±3 ±4 ±5 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF FREQUENCY LARGE-SIGNAL TRANSIENT RESPONSE ±6 5V/div 100 VS = ±2.5V TA = 25°C 80 60 0 40 45 20 90 0 135 -20 180 1 10 100 1K 10K 100K 1M PHASE SHIFT IN DEGREES OPEN LOOP VOLTAGE GAIN (dB) 120 2V/div VS = ±2.5V TA = 25°C RL = 100KΩ CL = 50pF 5µs/div 10M FREQUENCY (Hz) LARGE-SIGNAL TRANSIENT RESPONSE 2V/div 500mV/div ALD1731A/ALD1731 VS = ±1.0V TA = 25°C RL = 100KΩ CL = 50pF 5µs/div Advanced Linear Devices SMALL-SIGNAL TRANSIENT RESPONSE 100mV/div 20mV/div VS = ±2.5V TA = 25°C RL = 100KΩ CL = 50pF 2µs/div 5 of 9 TYPICAL APPLICATIONS RAIL-TO-RAIL VOLTAGE FOLLOWER/BUFFER RAIL-TO-RAIL VOLTAGE COMPARATOR +5V 5V ~ 1012Ω ZIN = VIN 0.1µF - 0.1µF - +5V OUTPUT + VIN 10M 0≤ VIN ≤ 5V * See Rail to Rail Waveform RAIL-TO-RAIL WAVEFORM HIGH INPUT IMPEDANCE RAIL-TO-RAIL PRECISION DC SUMMING AMPLIFIER INPUT +2.5V 10M V1 + V2 OUTPUT + 50K 10M - 10M 0V 0.1µF +5V OUTPUT 0V VOUT 10M +5V 0.1µF V3 V- ≤ VIN ≤ V+ - 2.5V V4 Performance waveforms. Upper trace is the output of a Wien Bridge Oscillator. Lower trace is the output of Rail-to-rail voltage follower. V- ≤ VOUT ≤ V+ 10M 10M VOUT = V1 + V2 - V3 - V4 RIN = 10MΩ Accuracy limited by resistor tolerances and input offset voltage WIEN BRIDGE OSCILLATOR (RAIL-TO-RAIL) SINE WAVE GENERATOR PHOTO DETECTOR CURRENT TO VOLTAGE CONVERTER RF = 5M +2.5V - I OUTPUT + + 10K R = 10K f =~ 1 2πRC +2.5V VOUT = I x RF PHOTODIODE 10K .01µF C = .01µF - 10K -2.5V -2.5V RL = 10K ~ 1.6KHz * See Rail to Rail Waveform LOW VOLTAGE INSTRUMENTATION AMPLIFIER V+ 0.1µF 1M + 100K - 500K V+ 100K V- 0.1µF 0.1µF - f max = 20KHz -40mV ≤ VIN ≤ 40mV VOUT 50K + V+ 0.1µF 1M V- 0.1µF V- 100K + V- ALD1731A/ALD1731 V+ 1M 100K 0.1µF 1M GAIN = 25 V- ≤ VOUT ≤ V+. All resistors are 1%. V+ = +1.0V, V- = -1.0V. Short circuit input current 1µA. Advanced Linear Devices 6 of 9 SOIC-8 PACKAGE DRAWING 8 Pin Plastic SOIC Package E Millimeters Dim S (45°) D A Min 1.35 Max 1.75 Min 0.053 Max 0.069 A1 0.10 0.25 0.004 0.010 b 0.35 0.45 0.014 0.018 C 0.18 0.25 0.007 0.010 D-8 4.69 5.00 0.185 0.196 E 3.50 4.05 0.140 0.160 1.27 BSC e A A1 e Inches 0.050 BSC H 5.70 6.30 0.224 0.248 L 0.60 0.937 0.024 0.037 ø 0° 8° 0° 8° S 0.25 0.50 0.010 0.020 b S (45°) H L ALD1731A/ALD1731 C ø Advanced Linear Devices 7 of 9 PDIP-8 PACKAGE DRAWING 8 Pin Plastic DIP Package E E1 Millimeters D S A2 A1 e b b1 A L Inches Dim Min Max Min Max A 3.81 5.08 0.105 0.200 A1 0.38 1.27 0.015 0.050 A2 1.27 2.03 0.050 0.080 b 0.89 1.65 0.035 0.065 b1 0.38 0.51 0.015 0.020 c 0.20 0.30 0.008 0.012 D-8 9.40 11.68 0.370 0.460 E 5.59 7.11 0.220 0.280 E1 7.62 8.26 0.300 0.325 e 2.29 2.79 0.090 0.110 e1 L 7.37 7.87 0.290 0.310 2.79 3.81 0.110 0.150 S-8 1.02 2.03 0.040 0.080 0° 15° 0° 15° ø c e1 ALD1731A/ALD1731 ø Advanced Linear Devices 8 of 9 CERDIP-8 PACKAGE DRAWING 8 Pin CERDIP Package E E1 Millimeters D A1 s A L L2 b b1 e L1 Min Inches Dim A 3.55 Max 5.08 0.140 Min Max 0.200 A1 1.27 2.16 0.050 0.085 b 0.97 1.65 0.038 0.065 b1 0.36 0.58 0.014 0.023 C 0.20 0.38 0.008 0.015 D-8 -- 10.29 -- 0.405 E 5.59 7.87 0.220 0.310 E1 7.73 8.26 0.290 0.325 e 2.54 BSC 0.100 BSC e1 7.62 BSC 0.300 BSC L 3.81 5.08 0.150 0.200 L1 3.18 -- 0.125 -- L2 0.38 1.78 0.015 0.070 S -- 2.49 -- 0.098 Ø 0° 15° 0° 15° C e1 ALD1731A/ALD1731 ø Advanced Linear Devices 9 of 9