CA5420A ® Data Sheet December 21, 2005 0.5MHz, Low Supply Voltage, Low Input Current BiMOS Operational Amplifiers The CA5420A is an integrated circuit operational amplifier that combines PMOS transistors and bipolar transistors on a single monolithic chip. It is designed and guaranteed to operate in microprocessor logic systems that use V+ = 5V, V- = GND, since it can operate down to ±1V supplies. It will also be suitable for 3.3V logic systems. The CA5420A BiMOS operational amplifier features gateprotected PMOS transistors in the input circuit to provide very high input impedance, very low input currents (less than 1pA). The internal bootstrapping network features a unique guardbanding technique for reducing the doubling of leakage current for every 10°C increase in temperature. The CA5420A operates at total supply voltages from 2V to 20V either single or dual supply. This operational amplifier is internally phase compensated to achieve stable operation in the unity gain follower configuration. Additionally, it has access terminals for a supplementary external capacitor if additional frequency roll-off is desired. Terminals are also provided for use in applications requiring input offset voltage nulling. The use of PMOS in the input stage results in common-mode input voltage capability down to 0.45V below the negative supply terminal, an important attribute for single supply application. The output stage uses a feedback OTA type amplifier that can swing essentially from rail-to-rail. The output driving current of 1.0mA (Min) is provided by using nonlinear current mirrors. This device has guaranteed specifications for 5V operation over the full military temperature range of -55°C to 125°C. The CA5420A has the same 8 lead pinout used for the industry standard 741. Functional Diagram Features • CA5420A at 5V Supply Voltage with Full Military Temperature Range Guaranteed Specifications • CA5420A Guaranteed to Operate from ±1V to ±10V Supplies • 2V Supply at 300µA Supply Current • 1pA (Typ) Input Current (Essentially Constant to 85°C) • Rail-to-Rail Output Swing (Drive ±2mA Into 1kΩ Load) • Pin Compatible with 741 Op Amp • Pb-Free Plus Anneal Available (RoHS Compliant) Applications • pH Probe Amplifiers • Picoammeters • Electrometer (High Z) Instruments • Portable Equipment • Inaccessible Field Equipment • Battery Dependent Equipment (Medical and Military) • 5V Logic Systems • Microprocessor Interface Ordering Information PART TEMP. PART NUMBER MARKING RANGE (°C) PACKAGE PKG. DWG. # CA5420AM 5420A -55 to 125 8 Ld SOIC M8.15 CA5420AMZ* (Note) 5420AMZ -55 to 125 8 Ld SOIC (Pb-free) M8.15 *Add “96” suffix for Tape and Reel. NOTE: Intersil Pb-free plus anneal products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. X1 MOS BIPOLAR + MOS BIPOLAR Pinout CA5420A (SOIC) TOP VIEW X1 BUFFER AMPS; BOOTSTRAPPED INPUT PROTECTION NETWORK FN1925.5 HIGH GAIN (50K) OTA BUFFER (X2) OFFSET 1 NULL INV. 2 INPUT NON-INV. 3 INPUT 8 STROBE + V- 4 7 V+ 6 OUTPUT 5 OFFSET NULL NOTE: Pin is connected to Case. 1 CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 1998, 2005. All Rights Reserved All other trademarks mentioned are the property of their respective owners. CA5420A Absolute Maximun Ratings Thermal Information Supply Voltage (Between V+ and V- Terminals) . . . . . . . . . . . . 22V Differential Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15V Input Voltage . . . . . . . . . . . . . . . . . . . . . . . . . (V+ + 8V) to (V- -0.5V) Input Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1mA Output Short Circuit Duration (Note 1). . . . . . . . . . . . . . . . Indefinite Thermal Resistance (Typical, Note 2) θJA (°C/W) θJC (°C/W) SOIC Package . . . . . . . . . . . . . . . . . . . 157 N/A Maximum Junction Temperature (Plastic Package) . . . . . . . 150°C Maximum Storage Temperature Range (All Types) . . . -65°C to 150°C Maximum Lead Temperature (Soldering 10s) . . . . . . . . . . . . 300°C (SOIC - Lead Tips Only) Operating Conditions Temperature Range. . . . . . . . . . . . . . . . . . . . . . . . . -55°C to 125°C CAUTION: Stresses above those listed in “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress only rating and operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. NOTES: 1. Short circuit may be applied to ground or to either supply. 2. θJA is measured with the component mounted on an evaluation PC board in free air. Electrical Specifications Typical Values Intended Only for Design Guidance. V+ = +5V; V- = GND, TA = 25°C PARAMETER SYMBOL TEST CONDITIONS CA5420A UNITS Input Resistance RI 150 TΩ Input Capacitance CI 4.9 pF Output Resistance RO 300 Ω Equivalent Input Noise Voltage eN 62 nV/√Hz 38 nV/√Hz Short-Circuit Current To Opposite Supply f = 1kHz RS = 100Ω f = 10kHz Source IOM+ 2.6 mA Sink IOM- 2.4 mA Gain Bandwidth Product fT 0.5 MHz Slew Rate SR 0.5 V/µs 0.7 µs Transient Response RL = 2kΩ, CL = 100pF Rise Time tr Overshoot OS 15 % Current from Terminal 8 To V- I8 + 20 µA Current from Terminal 8 To V+ I8- 2 mA Settling Time Electrical Specifications 0.01% AV = 1 2VP-P Input 8 µs 0.10% AV = 1 2VP-P Input 4.5 µs TA = 25°C, V+ = 5V, V- = 0, Unless Otherwise Specified PARAMETER TEST CONDITIONS SYMBOL CA5420A MIN TYP MAX UNITS Input Offset Voltage VIO VO = 2.5V - 1 5 mV Input Offset Current IIO VO = 2.5V - 0.02 0.5 pA - 0.02 1 pA Common Mode Rejection Ratio CMRR VCM = 0 to 3.7V, VO = 2.5V 75 83 - dB Common Mode Input Voltage Range VlCR+ VO = 2.5V 3.7 4 - V - -0.3 0 V ∆V+ = 1V; ∆V- = 1V 75 83 - dB VO = 0.5 to 4V RL = ∞ 85 87 - dB VO = 0.5 to 4V RL = 10kΩ 85 87 - dB VO = 0.7 to 3V RL = 2kΩ 80 85 - dB Input Current II VO = 2.5V VlCRPower Supply Rejection Ratio PSRR Large Signal Voltage Gain AOL 2 FN1925.5 December 21, 2005 CA5420A Electrical Specifications TA = 25°C, V+ = 5V, V- = 0, Unless Otherwise Specified (Continued) PARAMETER SYMBOL Source Current CA5420A TEST CONDITIONS MIN TYP MAX UNITS ISOURCE VO = 0V 1.2 2.7 - mA Sink Current ISINK VO = 5V 1.2 2.1 - mA Output Voltage VOM+ RL = ∞ 4.9 4.94 - V - 0.13 0.15 V VOMVOM+ RL = 10kΩ 4.7 4.9 - V - 0.12 0.15 V 3.5 4.6 - V - 0.1 0.15 V VO = 0V - 400 500 µA VO = 2.5V - 430 550 µA VOMVOM+ RL = 2kΩ VOMSupply Current ISUPPLY Electrical Specifications TA = -55°C to 125°C, V+ = 5V, V- = 0, Unless Otherwise Specified PARAMETER SYMBOL TEST CONDITIONS CA5420A MIN TYP MAX UNITS Input Offset Voltage VIO VO = 2.5V - 2 10 mV Input Offset Current IIO VO = 2.5V - 1.5 3 nA - 2 10 pA - 2 5 nA - 10 15 pA Up to TA = 85°C |II| Input Current VO = 2.5V Up to TA = 85°C Common Mode Rejection Ratio CMRR VCM = 0 to 3.7V, VO = 2.5V 70 80 - dB Common Mode Input Voltage Range VlCR+ VO = 2.5V 3.7 4 - V - -0.3 0 V ∆V+ = 1V; ∆V- = 1V 70 83 - dB VO = 0.5 to 4V RL = ∞ 85 87 - dB VO = 0.7 to 4V RL = 10kΩ 80 87 - dB VO = 0.7 to 2.5V RL = 2kΩ 75 80 - dB ISOURCE VO = 0V 1 2.7 - mA Sink Current ISINK VO = 5V 1 2.1 - mA Output Voltage VOM+ RL = ∞ 4.8 4.9 - V - 0.16 0.2 V 4.7 4.9 - V - 0.15 0.2 V 3 4 - V - 0.14 0.2 V VO = 0V - 430 550 µA VO = 2.5V - 480 600 µA VlCRPower Supply Rejection Ratio PSRR Large Signal Voltage Gain AOL Source Current VOMVOM+ RL = 10kΩ VOMVOM+ RL = 2kΩ VOMSupply Current ISUPPLY 3 FN1925.5 December 21, 2005 CA5420A For Equipment Design at VSUPPLY = ±1V, TA = 25°C, Unless Otherwise Specified Electrical Specifications PARAMETER SYMBOL TEST CONDITIONS CA5420A MIN TYP MAX UNITS Input Offset Voltage VIO - 2 5 mV Input Offset Current |IIO| - 0.01 4 (Note 3) pA |II| - 0.02 5 (Note 3) pA 20 100 - kV/V 86 100 - dB - 560 1000 µV/V 60 65 - dB - V Input Current Large Signal Voltage Gain AOL Common Mode Rejection Ratio RL = 10kΩ CMRR Common Mode Input Voltage Range VlCR+ 0.2 0.5 VlCR- -1 -1.3 - V Power Supply Rejection Ratio PSRR - 32 320 µV/V 70 90 - dB 0.9 0.95 - V VOM- -0.85 -0.91 - V ISUPPLY - 350 650 µA PD - 0.7 1.1 mW ∆VIO/∆T - 4 - µV/°C Maximum Output Voltage VOM+ Supply Current Device Dissipation Input Offset Voltage Temp. Drift Electrical Specifications RL = ∞ For Equipment Design at VSUPPLY = ±10V, TA = 25°C, Unless Otherwise Specified PARAMETER SYMBOL TEST CONDITIONS CA5420A MIN TYP MAX UNITS Input Offset Voltage VIO - 2 5 mV Input Offset Current |IIO| - 0.03 4 (Note 3) pA |II| - 0.05 5 (Note 3) pA 20 100 - kV/V Input Current Large Signal Voltage Gain AOL Common Mode Rejection Ratio RL = 10kΩ 86 100 - dB - 100 320 µV/V 70 80 - dB VlCR+ 9 9.3 - V VlCR- -10 -10.3 - V PSRR - 32 320 µV/V 70 90 - dB 9.7 9.9 - V CMRR Common Mode Input Voltage Range Power Supply Rejection Ratio VOM+ Maximum Output Voltage RL = ∞ VOM- -9.7 -9.85 - V ISUPPLY - 450 1000 µA Device Dissipation PD - 9 14 mW Input Offset Voltage Temperature Drift ∆VIO/∆T - 4 - µV/°C Supply Current NOTE: 3. The maximum limit represents the levels obtainable on high-speed automatic test equipment. Typical values are obtained under laboratory conditions. 4 FN1925.5 December 21, 2005 CA5420A Typical Applications High Input Resistance Voltmeter Picoammeter Circuit The exceptionally low input current (typically 0.2pA) makes the CA5420A highly suited for use in a picoammeter circuit. With only a single 10GΩ resistor, this circuit covers the range from ±1.5pA. Higher current ranges are possible with suitable switching techniques and current scaling resistors. Input transient protection is provided by the 1MΩ resistor in series with the input. Higher current ranges require that this resistor be reduced. The 10MΩ resistor connected to pin 2 of the CA5420A decouples the potentially high input capacitance often associated with lower current circuits and reduces the tendency for the circuit to oscillate under these conditions. 10GΩ 1MΩ 10MΩ + 1 Supply current in the standby position with the meter undeflected is 300µA. At full-scale deflection this current rises to 800µA. Carbon-zinc battery life should be in excess of 1,000 hours. +1.5V 500-0-500 µA 7 - CA5420A 3 The meter is placed in series with the gain network, thus eliminating the meter temperature coefficient error term. +1.5V 10pF 2 Advantage is taken of the high input impedance of the CA5420A in a high input resistance DC voltmeter. Only two 1.5V “AA” type penlite batteries power this exceedingly highinput resistance (>1,000,000MΩ) DC voltmeter. Full-scale deflection is ±500mV, ±150mV, and ±15mV. Higher voltage ranges are easily added with external input voltage attenuator networks. 5 6 BATTERY RETURNS 10kΩ 22MΩ M ±50pA 4 3 10MΩ CA5420A 100pF 2 1.5kΩ ±15pA 1.5kΩ 1% ±5pA 1kΩ 430Ω 1% ±1.5pA 150Ω 1% 5 6 M ±500mV 4 BATTERY RETURNS 10kΩ 1.5kΩ 1.5kΩ 1% ±150mV ±50mV 1kΩ 430Ω 1% ±15mV 150Ω 1% 1.1kΩ 68Ω 1% -1.5V -1.5V 11kΩ 1 500-0-500 µA 7 + 68Ω 1% FIGURE 2. HIGH INPUT RESISTANCE VOLTMETER FIGURE 1. PICOAMMETER CIRCUIT 1.0 OUTPUT STAGE TRANSISTOR SATURATION VOLTAGE, Q19 (mV) INPUT & OUTPUT VOLTAGE EXCURSIONS FROM THE POSITIVE AND NEGATIVE SUPPLY VOLTAGE (V) Typical Performance Curves TA = 25°C RL = 100kΩ 0.8 0.6 0.4 VO- 0.2 0 -0.2 VO+ -0.4 VICR- -0.6 VICR+ -0.8 -1.0 0 1 5 10 SUPPLY VOLTAGE (V) 15 FIGURE 3. OUTPUT VOLTAGE SWING AND COMMON MODE INPUT VOLTAGE RANGE vs SUPPLY VOLTAGE 5 10 TA = 25°C V- = 0V V+ = 2V V+ = 5V V+ = 10V 100 V+ = 20V 1000 0.001 0.1 1 LOAD (SOURCING) CURRENT (mA) 10 FIGURE 4. OUTPUT VOLTAGE vs LOAD SOURCING CURRENT FN1925.5 December 21, 2005 CA5420A 1000 (Continued) V+ = 5V V- = GND TA = 25°C V+ = 0V SUPPLY CURRENT (µA) OUTPUT STAGE TRANSISTOR SATURATION VOLTAGE, Q17 (mV) Typical Performance Curves V- = -20V V- = -10V V- = -5V V- = -2V 100 2000 1600 1200 800 400 10 0.01 0.1 1 LOAD (SINKING) CURRENT (mA) 10 0 FIGURE 5. OUTPUT VOLTAGE vs LOAD SINKING CURRENT 1 2 3 OUTPUT VOLTAGE (V) 4 5 FIGURE 6. SUPPLY CURRENT vs OUTPUT VOLTAGE 800 5.00 TA = 25°C V+ = 5V V- = GND RL TO GND 3.75 V+ = 5V V- = GND 700 INPUT BIAS CURRENT (pA) OUTPUT VOLTAGE SWING (V) 2400 2.50 1.25 600 500 400 300 200 100 0 1 10 100 LOAD RESISTANCE (kΩ) 0 25 1000 OPEN LOOP VOLTAGE GAIN (dB) EQUIVALENT INPUT NOISE VOLTAGE (nV√Hz) 100 101 103 104 105 FREQUENCY (Hz) FIGURE 9. INPUT NOISE VOLTAGE vs FREQUENCY 6 65 75 85 95 TEMPERATURE (°C) 106 105 115 TA = 25°C V+ = +10V, V- = 10V RL = 10kΩ CL = 0pF 100 0 -45 80 -90 60 -135 -180 40 20 0 102 55 TA = 25°C VS = ±10V VS = ±5V VS = ±1V 1 101 45 125 FIGURE 8. INPUT BIAS CURRENT DRIFT (∆IB/∆T) FIGURE 7. OUTPUT VOLTAGE SWING vs LOAD RESISTANCE 1000 35 1 101 102 103 104 105 OPEN LOOP PHASE (DEGREES) 0 106 FREQUENCY (Hz) FIGURE 10. OPEN LOOP GAIN AND PHASE SHIFT RESPONSE FN1925.5 December 21, 2005 CA5420A All Intersil U.S. products are manufactured, assembled and tested utilizing ISO9000 quality systems. Intersil Corporation’s quality certifications can be viewed at www.intersil.com/design/quality Intersil products are sold by description only. Intersil Corporation reserves the right to make changes in circuit design, software and/or specifications at any time without notice. Accordingly, the reader is cautioned to verify that data sheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com 7 FN1925.5 December 21, 2005