ADVANCED LINEAR DEVICES, INC. ALD2704A/ALD2704B ALD2704 DUAL RAIL-TO-RAIL CMOS OPERATIONAL AMPLIFIER GENERAL DESCRIPTION FEATURES The ALD2704 is a dual monolithic operational amplifier with MOSFET input that has rail-to-rail input and output voltage ranges. The input voltage range and output voltage range are very close to the positive and negative power supply voltages. Typically the input voltage can be beyond positive power supply voltage V + or the negative power supply voltage V- by up to 300mV. The output voltage swings to within 60mV of either positive or negative power supply voltages at rated load. • • • • • • • With high impedance load, the output voltage of the ALD2704 approaches within 1mV of the power supply rails. This device is designed as an alternative to the popular J-FET input operational amplifier in applications where lower operating voltages, such as 9V battery or ±3.25V to ±6V power supplies are being used. The ALD2704 offers high slew rate of 5V/µs. It is designed and manufactured with Advanced Linear Devices' standard enhanced ACMOS silicon gate CMOS process, and it offers low unit cost and exceptional reliability. The rail-to-rail input and output feature of the ALD2704 expands signal voltage range for a given operating supply voltage and allows numerous analog serial stages to be implemented without losing operating voltage margin. The output stage is designed to drive up to 10mA into 400pF capacitive and 1.5KΩ resistive loads at unity gain and up to 4000pF at a gain of 5. Short circuit protection to either ground or the power supply rails is at approximately 15mA clamp current. Due to complementary output stage design, the output can source and sink 10mA into a load with symmetrical drive and is ideally suited for applications where push-pull voltage drive is desired. For each of the operational amplifier, the offset voltage is trimmed on-chip to eliminate the need for external nulling in many applications. For precision applications, the output is designed to settle to 0.1% in 2µs. In large signal buffer applications, the operational amplifier can function as an ultrahigh input impedance voltage follower /buffer that allows input and output voltage swings from positive to negative supply voltages. This feature is intended to greatly simplify systems design and eliminate higher voltage power supplies in many applications. • • • • Rail-to-rail input and output voltage ranges Symmetrical push-pull output drives Output settles to 2mV of supply rails 5.0V/µs slew rate High capacitive load capability -- up to 4000pF No frequency compensation required -- unity gain stable Extremely low input bias currents -- <1.0pA typical (20pA max.) Ideal for high source impedance applications High voltage gain -- typically 100V/mV Output short circuit protected Unity gain bandwidth of 2.1MHz APPLICATIONS • • • • • • • • • • • • • • • Voltage amplifier Voltage follower/buffer Charge integrator Photodiode amplifier Data acquisition systems High performance portable instruments Signal conditioning circuits Low leakage amplifiers Active filters Sample/Hold amplifier Picoammeter Current to voltage converter Coaxial cable driver Capacitive sensor amplifier Piezoelectric transducer amplifier 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 Package 8-Pin Small Outline Package (SOIC) 8-Pin Plastic Dip Package ALD2704A DA ALD2704B DA ALD2704 DA ALD2704A SA ALD2704B SA ALD2704 SA ALD2704A PA ALD2704B PA ALD2704 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 -0.3V to V++13.2V ±6.6V -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 Supply voltage, V+ referenced to VSupply voltage, VS referenced to VDifferential input voltage range Power dissipation Operating temperature range PA, SA package DA package Storage temperature range Lead temperature, 10 seconds OPERATING ELECTRICAL CHARACTERISTICS TA = 25 °C VS = ±5.0V unless otherwise specified Min 2704A Typ Symbol Supply Voltage VS V+ Input Offset Voltage VOS Input Offset Current IOS 1.0 15 240 1.0 15 240 Input Bias Current IB 1.0 20 300 1.0 20 300 Input Voltage Range VIR Input Resistance RIN Input Offset Voltage Drift TCVOS Power Supply Rejection Ratio PSRR 65 80 65 80 60 Common Mode Rejection Ratio CMRR 65 83 65 83 Large Signal Voltage Gain AV 15 28 100 15 28 100 Output Voltage Range VO low VO high VO low VO high ±3.25 6.5 Max Min 2704B Typ Max Parameter ±6.0 ±3.25 12.0 6.5 4.90 4.99 5.3 2704 Typ Unit Test Conditions V V Dual Supply Single Supply 5.0 6.0 mV mV RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C 1.0 15 240 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C 1.0 20 300 pA pA TA = 25°C 0°C ≤ TA ≤ +70°C 5.3 V ±6.0 ±3.25 12.0 6.5 1.0 1.5 -5.3 Min ±6.0 12.0 2.0 3.0 -5.3 5.3 Max -5.3 10 12 10 12 1012 5 5 5 Ω µV/°C RS ≤ 100KΩ 80 dB R S ≤ 100KΩ 0°C ≤ TA ≤ +70°C 60 83 dB RS ≤ 100KΩ 0°C ≤ TA ≤ +70°C 10 28 100 V/mV V/mV RL = 100KΩ RL ≥ 1MΩ -4.96 -4.90 -4.96 -4.90 -4.96 -4.90 4.95 4.90 4.95 4.90 4.95 -4.998 -4.99 -4.998 -4.99 -4.998 -4.99 4.998 4.99 4.998 4.99 4.998 ISC 15 Supply Current IS 5.0 Power Dissipation PD Input Capacitance CIN 1 1 1 Bandwidth BW 2.1 2.1 2.1 MHz Slew Rate SR 5.0 5.0 5.0 V/µs AV = +1 RL = 2.0KΩ Rise time tr 0.1 0.1 0.1 µs RL = 2.0KΩ 15 15 15 % RL = 2.0KΩ CL = 100pF ALD2704A/ALD2704B ALD2704 6.5 5.0 65 15 V R L ≥ 10KΩ 0°C ≤ TA ≤ +70°C R L = 1MΩ 0°C ≤ TA ≤ +70°C Output Short Circuit Current Overshoot Factor 15 V 6.5 5.0 65 Advanced Linear Devices mA 6.5 65 mA mW VIN = -5V No Load Both amplifiers, No Load VS = ±5.0V pF 2 OPERATING ELECTRICAL CHARACTERISTICS (cont'd) TA = 25°C VS = ±5.0V unless otherwise specified 2704A Min Typ 2704B Max Min Typ 2704 Parameter Symbol Max Min Typ Maximum Load Capacitance CL 400 4000 400 4000 400 4000 Input Noise Voltage en 26 26 Input Current Noise in 0.6 Settling Time ts 5.0 2.0 Max Unit Test Conditions pF pF Gain = 1 Gain = 5 26 nV/√Hz f =1KHz 0.6 0.6 fA/√Hz f =10Hz 5.0 2.0 5.0 2.0 µs µs 0.01% 0.1% AV = 1 RL = 5KΩ CL= 50pF VS = ±5.0V -55°C ≤ TA ≤ +125°C unless otherwise specified 2704DA Typ Max Unit Test Conditions 4.0 7.0 mV RS ≤ 100KΩ 8.0 8.0 8.0 nA 10.0 10.0 10.0 nA Input Offset Voltage VOS 2.0 Input Offset Current IOS Input Bias Current IB Power Supply Rejection Ratio PSRR 60 75 60 75 60 75 dB RS ≤ 100KΩ Common Mode Rejection Ratio CMRR 60 83 60 83 60 83 dB RS ≤ 100KΩ Large Signal Voltage Gain AV 10 25 10 25 10 25 V/mV RL = 10KΩ V RL = 10KΩ VO low Range VO high ALD2704A/ALD2704B ALD2704 -4.9 4.8 4.9 Min 2704BDA Typ Max Symbol Output Voltage Min 2704ADA Typ Max Parameter -4.8 -4.9 4.8 4.9 Min -4.8 -4.9 4.8 Advanced Linear Devices 4.9 -4.8 3 Design & Operating Notes: 1. The ALD2704 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. The ALD2704 is internally compensated for unity gain stability using a novel scheme. This design 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. A unity gain buffer using the ALD2704 will typically drive 400pF of external load capacitance without stability problems. In the inverting unity gain configuration, it can drive up to 800pF of load capacitance. Compared to other CMOS operational amplifiers, the ALD2704 is much more resistant to parasitic oscillations. 2. The ALD2704 has complementary p-channel and n-channel input differential stages connected in parallel to accomplish rail to rail input common mode voltage range. With the 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 above the negative supply voltage. As offset voltage trimming on the ALD2704 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 greater than 2 (10V operation), where the common mode voltage does not make excursions below this switching point. 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. 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. The voltage follower configuration, the oscillation and resistant with the rail- to-rail input and output feature, makes the ALD2704 an effective analog signal buffer for medium to high source impedance sensors, transducers, and other circuit networks. 5. The ALD2704 operational amplifier has been designed to provide 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. 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. Alternatively, a 100KΩ or higher value resistor at the input terminals will limit input currents to acceptable levels while causing very small or negligible accuracy effects. 3. The input bias and offset currents are essentially input protection TYPICAL PERFORMANCE CHARACTERISTICS COMMON MODE INPUT VOLTAGE RANGE AS A FUNCTION OF SUPPLY VOLTAGE OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF SUPPLY VOLTAGE AND TEMPERATURE ±7 1000 } -55°C ±6 OPEN LOOP VOLTAGE GAIN (V/mV) COMMON MODE INPUT VOLTAGE RANGE (V) TA = 25°C ±5 ±4 ±3 ±2 } +125°C 10 RL = 10KΩ RL = 5KΩ 1 ±3 ±2 ±4 ±5 ±6 ±7 ±2 0 ±4 ±6 ±8 SUPPLY VOLTAGE (V) SUPPLY VOLTAGE (V) INPUT BIAS CURRENT AS A FUNCTION OF AMBIENT TEMPERATURE SUPPLY CURRENT AS A FUNCTION OF SUPPLY VOLTAGE 8 10000 VS = ±5.0V 1000 SUPPLY CURRENT (mA) INPUT BIAS CURRENT (pA) } +25°C 100 100 10 1.0 INPUTS GROUNDED OUTPUT UNLOADED 7 6 5 TA = -55°C 4 -25°C +25°C +80°C +125°C 3 2 1 0 0.1 -50 -25 0 25 50 75 100 0 125 AMBIENT TEMPERATURE (°C) ALD2704A/ALD2704B ALD2704 ±1 ±2 ±3 ±4 ±5 ±6 ±7 SUPPLY VOLTAGE (V) Advanced Linear Devices 4 TYPICAL PERFORMANCE CHARACTERISTICS 120 100 OPEN LOOP VOLTAGE GAIN (dB) ±25°C ≤ TA ≤ 125°C ±6 RL = 10KΩ ±5 RL = 10KΩ ±4 RL = 2KΩ ±3 ±2 VS = ±5.0V TA = 25°C 80 60 0 40 45 20 90 0 135 180 -20 0 ±1 ±2 ±3 ±4 ±5 ±6 ±7 1 10 100 1K 10K 100K 1M PHASE SHIFT IN DEGREES 10M SUPPLY VOLTAGE (V) FREQUENCY (Hz) INPUT OFFSET VOLTAGE AS A FUNCTION OF AMBIENT TEMPERATURE REPRESENTATIVE UNITS INPUT OFFSET VOLTAGE AS A FUNCTION OF COMMON MODE INPUT VOLTAGE 15 +5 +4 INPUT OFFSET VOLTAGE (mV) OUTPUT VOLTAGE SWING (V) ±7 INPUT OFFSET VOLTAGE (mV) OPEN LOOP VOLTAGE AS A FUNCTION OF FREQUENCY OUTPUT VOLTAGE SWING AS A FUNCTION OF SUPPLY VOLTAGE VS = ±5.0V +3 +2 +1 0 -1 -2 -3 -4 VS = ±5.0V TA = 25ºC 10 5 0 -5 -10 -15 -5 -50 -25 0 +25 +50 +75 +100 +125 -4 AMBIENT TEMPERATURE (°C) -2 0 +2 +4 +6 COMMON MODE INPUT VOLTAGE (V) OPEN LOOP VOLTAGE GAIN AS A FUNCTION OF LOAD RESISTANCE LARGE - SIGNAL TRANSIENT RESPONSE OPEN LOOP VOLTAGE GAIN (V/mV) 1000 5V/div VS = ±5.0V TA = 25°C RL = 1KΩ CL = 50pF 5V/div 2µs/div 100 VS = ±5.0V TA = 25°C 10 1 1K 10K 100K 1000K LOAD RESISTANCE (Ω) SMALL - SIGNAL TRANSIENT RESPONSE VOLTAGE NOISE DENSITY AS A FUNCTION OF FREQUENCY VOLTAGE NOISE DENSITY (nV/ √ Hz) 150 100mV/div 125 VS = ±5.0V TA = 25°C 100 VS = ± 5.0V TA = 25°C RL = 1.0KΩ CL = 50pF 75 50 25 50mV/div 0 10 100 ALD2704A/ALD2704B ALD2704 1K 10K FREQUENCY (Hz) 100K 1µs/div 1000K Advanced Linear Devices 5 TYPICAL APPLICATIONS RAIL-TO-RAIL VOLTAGE FOLLOWER/BUFFER RAIL-TO-RAIL VOLTAGE COMPARATOR +12V +10V = 1012Ω ZIN ~ 0.1µF VIN VIN CL + VOUT +12V RL ≥ 1.5KΩ 400pF 0 ≤ VIN ≤ 10V 0.1µF - VOUT + 50K 10M LOW OFFSET SUMMING AMPLIFIER PHOTO DETECTOR CURRENT TO VOLTAGE CONVERTER RF = 5M 10K 50K +5V INPUT 1 0.1µF I - INPUT 2 10K VOUT GAIN = 5 + * Circuit Drives Large Load Capacitance ≤ 4000pF +5V - CL = 4000pF RL ≥ 1.5K + -5V -5V 0.1µF WIEN BRIDGE OSCILLATOR (RAIL-TO -RAIL) SINE WAVE GENERATOR BANDPASS NETWORK C2 R2 +5V - C1 VOUT + 10K -5V R1 VIN - +5V VOUT + .01µF R = 10K C = .01µF ~ f= Low Frequency Breakpoint ƒL = 10K 1 ~ 1.6K Hz = 2πRC RF VIN R1 C1 1 = 160Hz 2π R1C1 High Frequency Cutoff ƒH = R1 = 10K C1 = 100nF R2 = 10K C2 = 500pF 1 = 32KHz 2π R2 C 2 PRECISION CHARGE INTEGRATOR 100K 1000pF 5K R1 -5V 10K LOW PASS FILTER (RFI FILTER) 5K VOUT = I X RF PHOTODIODE +9V - 0.02µF VOUT +5V 1MΩ VIN - + VOUT + -5V Cutoff frequency = 1 = 3.2kHz π R1C1 Gain = 10 Frequency roll-off 20dB/decade ALD2704A/ALD2704B ALD2704 Advanced Linear Devices 6