Precision, Micropower Operational Amplifiers OP193/OP293 APPLICATIONS Digital scales Strain gages Portable medical equipment Battery-powered instrumentation Temperature transducer amplifier PIN CONFIGURATIONS NULL 1 –IN A 2 OP193 +IN A 3 TOP VIEW V– 4 (Not to Scale) 8 NC 7 V+ 6 OUT A 5 NULL NC = NO CONNECT 00295-001 Operates from +1.7 V to ±18 V Low supply current: 15 µA/amplifier Low offset voltage: 100 µV maximum Outputs sink and source: ±8 mA No phase reversal Single- or dual-supply operation High open-loop gain: 600 V/mV Unity-gain stable Figure 1. 8-Lead SOIC_N (S Suffix) OUT A 1 –IN A 2 +IN A 3 OP293 TOP VIEW V– 4 (Not to Scale) 8 V+ 7 OUT B 6 –IN B 5 +IN B 00295-002 FEATURES Figure 2. 8-Lead SOIC_N (S Suffix) GENERAL DESCRIPTION The OP193/OP293 are single-supply operational amplifiers that feature a combination of high precision, low supply current, and the ability to operate at low voltages. For high performance in single-supply systems, the input and output ranges include ground, and the outputs swing from the negative rail to within 600 mV of the positive supply. For low voltage operation, the OP193/OP293 can operate down to +1.7 V or ±0.85 V. The combination of high accuracy and low power operation make the OP193/OP293 useful for battery-powered equipment. The part’s low current drain and low voltage operation allow it to continue performing long after other amplifiers have ceased functioning either because of battery drain or headroom. The OP193/OP293 are specified for single +2 V through dual ±15 V operation over the extended (−40°C to +125°C) temperature range. They are available in SOIC surface-mount packages. Rev. C Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties that may result from its use. Specifications subject to change without notice. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Trademarks and registered trademarks are the property of their respective owners. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781.329.4700 www.analog.com Fax: 781.461.3113 ©1995–2009 Analog Devices, Inc. All rights reserved. OP193/OP293 TABLE OF CONTENTS Features .............................................................................................. 1 Input Overvoltage Protection ................................................... 14 Applications ....................................................................................... 1 Output Phase Reversal—OP193............................................... 14 General Description ......................................................................... 1 Output Phase Reversal—OP293............................................... 14 Pin Configurations ........................................................................... 1 Battery-Powered Applications .................................................. 14 Revision History ............................................................................... 2 A Micropower False-Ground Generator................................. 15 Specifications..................................................................................... 3 A Battery-Powered Voltage Reference ..................................... 15 Electrical Specifications ............................................................... 3 A Single-Supply Current Monitor ............................................ 15 Absolute Maximum Ratings............................................................ 8 A Single-Supply Instrumentation Amplifier .......................... 16 Thermal Resistance ...................................................................... 8 ESD Caution .................................................................................. 8 A Low Power, Temperature to 4 mA to 20 mA Transmitter .................................................................................. 16 Typical Performance Characteristics ............................................. 9 A Micropower Voltage Controlled Oscillator ........................ 17 Functional Description .................................................................. 13 Outline Dimensions ....................................................................... 18 Driving Capacitive Loads .......................................................... 13 Ordering Guide .......................................................................... 18 REVISION HISTORY 9/09—Rev. B to Rev. C Updated Format .................................................................. Universal Deleted OP493 .................................................................... Universal Changes to Features and General Description Sections.............. 1 Deleted 8-Lead Epoxy DIP Pin Configurations for OP193 and OP293, and 14-Lead Epoxy DIP and 16-Lead Wide Body SOL Pin Configurations for OP493 ........................................................ 1 Changes to Offset Voltage Parameter and Large Signal Voltage Gain, RL = 100 kΩ, −10 V ≤ VOUT ≤ +10 V Parameter, and Power Supply Rejection Ratio Parameter, Table 1........................ 3 Changes to Offset Voltage Parameter and Power Supply Rejection Ratio Parameter, Table 2 ................................................ 4 Changes to Offset Voltage Parameter and Power Supply Rejection Ratio Parameter, Table 3 ................................................ 6 Changes to Offset Voltage Parameter and Power Supply Rejection Ratio Parameter, Table 4 ................................................ 7 Changes to Table 5 and Table 6 ....................................................... 8 Changes to Figure 3 to Figure 6 ...................................................... 9 Changes to Figure 10 and Figure 12 ............................................. 10 Changes to Functional Description Section and Figure 26 ...... 13 Deleted A Micropower, Single-Supply Quad Voltage Output 8-Bit DAC Section .......................................................................... 13 Deleted Figure 13; Renumbered Sequentially ............................ 14 Deleted A Single-Supply Micropower Quad ProgrammableGain Amplifier Section .................................................................. 14 Changes to Output Phase Reversal—OP293 Section, BatteryPowered Applications Section, and Figure 27 ............................ 14 Deleted Figure 14............................................................................ 15 Changes to Figure 31, A Single-Supply Current Monitor Section, and Figure 32.................................................................... 15 Changes to A Low Power, Temperature to 4 mA to 20 mA Transmitter Section and Figure 35 ............................................... 16 Updated Outline Dimensions ....................................................... 18 Changes to Ordering Guide .......................................................... 18 1/02—Rev. A to Rev. B Deletion of Wafer Test Limits Table ................................................5 Deletion of Dice Characteristics Images ........................................6 Edits to Ordering Guide ...................................................................6 Rev. C | Page 2 of 20 OP193/OP293 SPECIFICATIONS ELECTRICAL SPECIFICATIONS VS = ±15.0 V, TA = 25°C, unless otherwise noted. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions VOS OP193 OP193, −40°C ≤ TA ≤ +125°C OP293 OP293, −40°C ≤ TA ≤ +125°C VCM = 0 V, −40°C ≤ TA ≤ +125°C VCM = 0 V, −40°C ≤ TA ≤ +125°C Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection IB IOS VCM CMRR Large Signal Voltage Gain AVO Large Signal Voltage Gain Large Signal Voltage Gain Long-Term Offset Voltage 1 Offset Voltage Drift2 OUTPUT CHARACTERISTICS Output Voltage Swing High AVO AVO −14.9 V ≤ VCM ≤ +14 V −14.9 V ≤ VCM ≤ +14 V, −40°C ≤ TA ≤ +125°C RL = 100 kΩ, −10 V ≤ VOUT ≤ +10 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C RL = 10 kΩ, −10 V ≤ VOUT ≤ +10 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C RL = 2 kΩ, −10 V ≤ VOUT ≤ +10 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −14.9 100 97 500 300 VOH VOL Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio ISC Supply Current per Amplifier ISY PSRR en in en p-p E Grade Typ Max 100 200 15 2 +13.5 116 600 200 125 VS = ±1.5 V to ±18 V −40°C ≤ TA ≤ +125°C VOUT = 0 V, VS = ±18 V, −40°C ≤ TA ≤ +125°C, RL = ∞ 100 97 150 250 250 350 20 4 +13.5 116 600 150 V/mV V/mV V/mV 100 14.1 −14.7 +14.2 ±25 300 14.1 14.0 13.9 −14.6 −14.4 −14.1 120 14.2 14.1 −14.7 +14.2 ±25 97 94 −14.6 −14.4 −14.1 120 30 65 0.05 3 μV μV μV μV nA nA V dB dB 300 150 1.75 14.2 Unit V/mV V/mV V/mV 200 125 100 14.1 14.0 13.9 F Grade Typ Max 350 200 150 IL = 1 mA IL = 1 mA, −40°C ≤ TA ≤ +125°C IL = 5 mA IL = −1 mA IL = −1 mA, −40°C ≤ TA ≤ +125°C IL = −5 mA Rev. C | Page 3 of 20 −14.9 97 94 500 300 350 200 0.2 f = 1 kHz f = 1 kHz 0.1 Hz to 10 Hz Min 300 VOS ΔVOS/ΔT Output Voltage Swing Low NOISE PERFORMANCE Voltage Noise Density Current Noise Density Voltage Noise Min 30 65 0.05 3 V/mV V/mV V/mV μV μV/°C V V V V V V mA dB dB μA nV/√Hz pA/√Hz μV p-p OP193/OP293 Parameter DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Channel Separation 1 2 Symbol Conditions SR GBP RL = 2 kΩ Min E Grade Typ Max Min 15 35 120 VOUT = 10 V p-p, RL = 2 kΩ, f = 1 kHz F Grade Typ Max 15 35 120 Unit V/ms kHz dB Long-term offset voltage is guaranteed by a 1000 hour life test performed on three independent lots at 125 °C, with an LTPD of 1.3. Offset voltage drift is the average of the −40°C to +25°C delta and the +25°C to +125°C delta. VS = 5.0 V, VCM = 0.1 V, TA = 25°C, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions VOS OP193 OP193, −40°C ≤ TA ≤ +125°C OP293 OP293, −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection IB IOS VCM CMRR Large Signal Voltage Gain AVO Large Signal Voltage Gain Long-Term Offset Voltage1 Offset Voltage Drift2 OUTPUT CHARACTERISTICS Output Voltage Swing High Output Voltage Swing Low E Grade Min Typ Max AVO 0.1 V ≤ VCM ≤ 4 V 0.1 V ≤ VCM ≤ 4 V, −40°C ≤ TA ≤ +125°C RL = 100 kΩ, 0.03 V ≤ VOUT ≤ 4.0 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C RL = 10 kΩ, 0.03 V ≤ VOUT ≤ 4.0 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C 0 100 92 VOL Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio ISC Supply Current per Amplifier ISY PSRR 116 200 125 VS = ±1.7 V to ±6.0 V −40°C ≤ TA ≤ +125°C VCM = 2.5 V, RL = ∞ Rev. C | Page 4 of 20 70 150 1.25 4.4 4.4 4.4 140 300 4.1 4.0 4.0 160 700 ±8 100 94 120 4.4 140 V V mV 14.5 160 220 700 ±8 97 90 V/mV V/mV V/mV μV μV/°C V V 5 280 400 500 900 μV μV μV μV nA nA V dB dB 4.4 4.4 220 5 280 Unit V/mV V/mV V/mV 75 50 70 4.0 4.0 116 130 75 50 4.1 150 250 250 350 20 4 4 200 125 0.2 IL = 100 μA IL = 1 mA IL = 1 mA, −40°C ≤ TA ≤ +125°C IL = 5 mA IL = −100 μA IL = −100 μA, −40°C ≤ TA ≤ +125°C No load IL = −1 mA IL = −1 mA, −40°C ≤ TA ≤ +125°C IL = –5 mA 0 96 92 130 VOS ΔVOS/ΔT VOH 100 200 15 2 4 F Grade Min Typ Max 120 14.5 400 500 900 mV mV mV mV mV mA dB dB μA OP193/OP293 Parameter NOISE PERFORMANCE Voltage Noise Density Current Noise Density Voltage Noise DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product 1 2 Min E Grade Typ Max Min F Grade Typ Max Symbol Conditions en in en p-p f = 1 kHz f = 1 kHz 0.1 Hz to 10 Hz 65 0.05 3 65 0.05 3 nV/√Hz pA/√Hz μV p-p SR GBP RL = 2 kΩ 12 35 12 35 V/ms kHz Long-term offset voltage is guaranteed by a 1000 hour life test performed on three independent lots at 125 °C, with an LTPD of 1.3. Offset voltage drift is the average of the −40°C to +25°C delta and the +25°C to +125°C delta. Rev. C | Page 5 of 20 Unit OP193/OP293 VS = 3.0 V, VCM = 0.1 V, TA = 25°C, unless otherwise noted. Table 3. Parameter Symbol Conditions INPUT CHARACTERISTICS Offset Voltage VOS OP193 OP193, −40°C ≤ TA ≤ +125°C OP293 OP293, −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C Input Bias Current Input Offset Current Input Voltage Range Common-Mode Rejection IB IOS VCM CMRR Large Signal Voltage Gain AVO Long-Term Offset Voltage1 Offset Voltage Drift2 VOH Output Voltage Swing Low VOL Short-Circuit Current POWER SUPPLY Power Supply Rejection Ratio ISC Supply Current per Amplifier ISY DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Channel Separation 1 2 0 97 90 PSRR E Grade Typ Max 100 200 15 2 2 116 100 75 0 94 87 IL = 1 mA IL = 1 mA, –40°C ≤ TA ≤ +125°C IL = 5 mA IL = −1 mA IL = −1 mA, −40°C ≤ TA ≤ +125°C IL = −5 mA 2.1 1.9 1.9 VS = +1.7 V to +6 V −40°C ≤ TA ≤ +125°C VCM = 1.5 V, RL = ∞ −40°C ≤ TA ≤ +125°C 100 94 F Grade Typ Max 150 250 250 350 20 4 2 116 100 75 0.2 VS Min 100 VOS ΔVOS/ΔT OUTPUT CHARACTERISTICS Output Voltage Swing High Supply Voltage Range NOISE PERFORMANCE Voltage Noise Density Current Noise Density Voltage Noise 0.1 ≤ VCM ≤ 2 V 0.1 ≤ VCM ≤ 2 V, −40°C ≤ TA ≤ +125°C RL = 100 kΩ, 0.03 V ≤ VOUT ≤ 2 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Min 100 150 1.25 2.14 2.1 280 700 ±8 300 2.1 1.9 1.9 400 500 900 2.14 2.1 280 700 ±8 400 500 900 97 90 14.5 +2 22 22 ±18 14.5 +2 22 22 ±18 Unit μV μV μV μV nA nA V dB dB V/mV V/mV V/mV μV μV/°C V V V mV mV mV mA dB dB μA μA V en in en p-p f = 1 kHz f = 1 kHz 0.1 Hz to 10 Hz 65 0.05 3 65 0.05 3 nV/√Hz pA/√Hz μV p-p SR GBP RL = 2 kΩ 10 25 120 10 25 120 V/ms kHz dB VOUT = 10 V p-p, RL = 2 kΩ, f = 1 kHz Long-term offset voltage is guaranteed by a 1000 hour life test performed on three independent lots at 125 °C, with an LTPD of 1.3. Offset voltage drift is the average of the –40°C to +25°C delta and the +25°C to +125°C delta. Rev. C | Page 6 of 20 OP193/OP293 VS = 2.0 V, VCM = 0.1 V, TA = 25°C, unless otherwise noted. Table 4. Parameter INPUT CHARACTERISTICS Offset Voltage Input Bias Current Input Offset Current Input Voltage Range Large Signal Voltage Gain Long-Term Offset Voltage POWER SUPPLY Power Supply Rejection Ratio Symbol Conditions VOS OP193 OP193, −40°C ≤ TA ≤ +125°C OP293 OP293, −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C IB IOS VCM AVO Min E Grade Typ Max 100 175 15 2 1 0 RL = 100 kΩ, 0.03 V ≤ VOUT ≤ 1 V −40°C ≤ TA ≤ +125°C 60 Supply Current/Amplifier ISY Supply Voltage Range NOISE PERFORMANCE Voltage Noise Density Current Noise Density Voltage Noise DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product VS F Grade Typ Max 0 VS = 1.7 V to 6 V −40°C ≤ TA ≤ +125°C VCM = 1.0 V, RL = ∞ −40°C ≤ TA ≤ +125°C μV μV μV μV nA nA V 300 V/mV V/mV μV 20 25 ±18 dB dB μA μA V 70 150 100 94 97 90 13.2 +2 20 25 ±18 13.2 +2 Unit 150 250 250 350 20 4 1 60 70 VOS PSRR Min en in en p-p f = 1 kHz f = 1 kHz 0.1 Hz to 10 Hz 65 0.05 3 65 0.05 3 nV/√Hz pA/√Hz μV p-p SR GBP RL = 2 kΩ 10 25 25 V/ms kHz Rev. C | Page 7 of 20 OP193/OP293 ABSOLUTE MAXIMUM RATINGS Table 5. Parameter Supply Voltage1 Input Voltage1 Differential Input Voltage1 Output Short-Circuit Duration to GND Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature (Soldering, 60 sec) 1 Rating ±18 V ±18 V ±18 V Indefinite −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C For supply voltages less than ±18 V, the input voltage is limited to the supply voltage. Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 6. Thermal Resistance Package Type 8-Lead SOIC_N (S) 1 θJA1 158 θJC 43 Unit °C/W θJA is specified for the worst-case conditions. θJA is specified for a device soldered in a circuit board for the SOIC package. ESD CAUTION Rev. C | Page 8 of 20 OP193/OP293 TYPICAL PERFORMANCE CHARACTERISTICS 150 200 VS = ±15V TA = 25°C VS = ±15V –40°C ≤ TA ≤ +125°C 120 NUMBER OF AMPLIFIERS 120 80 90 60 –60 –45 –30 –15 0 15 30 45 60 75 OFFSET (µV) 0 00295-003 0 –75 0 0.6 0.8 1.0 Figure 6. TCVOS Distribution, VS = ±15 V 200 1 VS = 3V VCM = 0.1V TA = 25°C 160 VS = 5V 0 120 80 40 –40°C –1 –2 +125°C –3 –60 –45 –30 –15 0 15 30 45 60 75 OFFSET (µV) –4 00295-004 0 –75 +25°C 0 1 2 3 4 5 COMMON-MODE VOLTAGE (V) Figure 4. Offset Distribution, VS = +3 V 00295-007 INPUT BIAS CURRENT (nA) NUMBER OF AMPLIFIERS 0.4 TCVOS (µV/°C) Figure 3. Offset Distribution, VS = ±15 V Figure 7. Input Bias Current vs. Common-Mode Voltage 150 120 VS = 3V VCM = 0.1V –40°C ≤ TA ≤ +125°C 5V ≤ VS ≤ 30V TA = 25°C 100 120 –PSRR 80 PSRR (dB) 90 60 60 +PSRR 40 30 20 0 0 0.2 0.4 0.6 0.8 TCVOS (µV/°C) 1.0 0 10 00295-005 NUMBER OF AMPLIFIERS 0.2 00295-006 30 40 100 1k FREQUENCY (Hz) Figure 5. TCVOS Distribution, VS = +3 V Figure 8. PSRR vs. Frequency Rev. C | Page 9 of 20 10k 00295-008 NUMBER OF AMPLIFIERS 160 OP193/OP293 0 120 TA = 25°C 60 VS = +5V 40 20 100 10k 1k FREQUENCY (Hz) –0.10 VS = +2V VCM = 0.1V –0.15 –0.20 –0.25 –50 00295-009 0 10 –0.05 20 –1 INPUT BIAS CURRENT (nA) +SR = –SR VS = ±15V +SR = –SR VS = +5V 10 –2 100 125 VS = ±15V –3 VS = +2V VCM = 0.1V 25 50 75 100 125 –5 –50 –25 0 25 50 75 100 125 TEMPERATURE (°C) Figure 10. Slew Rate vs. Temperature Figure 13. Input Bias Current vs. Temperature 40 25 +ISC VS = ±15V SUPPLY CURRENT (μA) | –ISC | VS = ±15V 20 | –ISC | VS = +5V –25 VS = ±18V 20 +ISC VS = +5V 0 25 50 15 VS = +2V VCM = 1V 10 5 75 100 TEMPERATURE (°C) 125 00295-011 SHORT-CIRCUIT CURRENT (mA) 75 00295-013 0 00295-010 –25 TEMPERATURE (°C) 0 –50 50 –4 5 10 25 Figure 11. Short-Circuit Current vs. Temperature 0 –50 –25 0 25 50 75 100 TEMPERATURE (°C) Figure 14. Supply Current vs. Temperature Rev. C | Page 10 of 20 125 00295-014 SLEW RATE (V/ms) 0 30 0 Figure 12. Input Offset Current vs. Temperature 25 0 –50 –25 TEMPERATURE (°C) Figure 9. CMRR vs. Frequency 15 VS = ±15V 00295-012 VS = ±15V 80 CMRR (dB) INPUT OFFSET CURRENT (nA) 100 OP193/OP293 2500 5V ≤ VS ≤ 30V TA = 25°C VOLTAGE GAIN (V/mV) 2000 100 10 VS = ±15V –10V ≤ VOUT ≤ +10V 1500 1000 VS = +5V 0.03V ≤ VOUT ≤ 4V 1 0.1 1 10 100 1k FREQUENCY (Hz) 0 –50 50 75 125 100 1000 VOLTAGE GAIN (V/mV) 800 100 10 VS = ±15V –10V ≤ VOUT ≤ +10V 600 400 VS = +5V 0.03V ≤ VOUT ≤ 4V 1 10 100 1k FREQUENCY (Hz) 0 –50 100 DELTA FROM VEE 75 125 100 VS = 5V TA = 25°C 40 20 10 100 1k CURRENT LOAD (µA) 10k 00295-017 1 –20 10 100 1k 10k FREQUENCY (Hz) Figure 20. Closed-Loop Gain vs. Frequency, VS = 5 V Figure 17. Delta Output Swing vs. Current Load Rev. C | Page 11 of 20 100k 00295-020 0 10 1 0.1 50 60 GAIN (dB) DELTA FROM VCC 25 Figure 19. Voltage Gain (RL = 10 kΩ) vs. Temperature 5V ≤ VS ≤ 30V TA = 25°C 1k 0 TEMPERATURE (°C) Figure 16. Current Noise Density vs. Frequency 10k –25 00295-019 200 00295-016 CURRENT NOISE DENSITY (pA/ Hz) 25 Figure 18. Voltage Gain (RL = 100 kΩ) vs. Temperature 5V ≤ VS ≤ 30V TA = 25°C 1 0.1 DELTA FROM SUPPLY RAIL (mV) 0 TEMPERATURE (°C) Figure 15. Voltage Noise Density vs. Frequency 1k –25 00295-018 500 00295-015 VOLTAGE NOISE DENSITY (nV/ Hz) 1k OP193/OP293 60 60 VS = ±15V TA = 25°C VS = 5V 40 PHASE 90 20 20 45 GAIN 0 0 PHASE (Degrees) GAIN (dB) GAIN (dB) 40 0 –20 1k 10k 100k FREQUENCY (Hz) –40 100 10k –90 1M 100k FREQUENCY (Hz) Figure 21. Closed-Loop Gain vs. Frequency, VS = ±15 V Figure 23. Open-Loop Gain and Phase vs. Frequency 60 60 VS = 5V TA = 25°C AV = 1 50mV ≤ VIN ≤ 150mV LOADS TO GND VS = ±15V 90 40 +OS = | –OS | RL = 50kΩ 30 GAIN (dB) 40 +OS RL = ∞ 45 20 GAIN 0 0 20 –OS RL = ∞ 0 10 100 –20 +OS = | –OS | RL = 10kΩ 1k CAPACITIVE LOAD (pF) 10k 00295-022 10 Figure 22. Small Signal Overshoot vs. Capacitive Load –40 100 –45 1k 10k 100k –90 1M FREQUENCY (Hz) Figure 24. Open-Loop Gain and Phase vs. Frequency Rev. C | Page 12 of 20 PHASE (Degrees) PHASE 00295-024 50 OVERSHOOT (%) 1k 00295-023 100 00295-021 –20 10 –45 OP193/OP293 FUNCTIONAL DESCRIPTION V+ The OP193/OP293 operational amplifiers are single-supply, micropower, precision amplifiers whose input and output ranges both include ground. Input offset voltage (VOS) is only 100 μV maximum, while the output delivers ±5 mA to a load. Supply current is only 15 μA. Q4 FROM INPUT STAGE A simplified schematic of the input stage is shown in Figure 26. The input transistors, Q1 and Q2, are PNP devices, which permit the inputs to operate down to ground potential. The input transistors have resistors in series with the base terminals to protect the junctions from overvoltage conditions. The second stage is an NPN cascode that is buffered by an emitter follower before driving the final PNP gain stage. The OP193 includes connections to taps on the input load resistors, which can be used to null the input offset voltage, VOS. The OP293 have two additional transistors, Q7 and Q8. The behavior of these transistors is discussed in the Output Phase Reversal—OP193 and Output Phase Reversal—OP293 sections. The output stage, shown in Figure 25, is a noninverting NPN totem-pole configuration. Current is sourced to the load by Emitter Follower Q1, while Q2 provides current sink capability. When Q2 saturates, the output is pulled to within 5 mV of ground without an external pull-down resistor. The totem-pole output stage supplies a minimum of 5 mA to an external load, even when operating from a single 3.0 V power supply. Q1 I3 I2 V– Figure 25. OP193/OP293 Equivalent Output Circuit By operating as an emitter follower, Q1 offers a high impedance load to the final PNP collector of the input stage. Base drive to Q2 is derived by monitoring Q1’s collector current. Transistor Q5 tracks the collector current of Q1. When Q1 is on, Q5 keeps Q4 off, and Current Source I1 keeps Q2 turned off. When Q1 is driven to cutoff (that is, the output must move toward V−), Q5 allows Q4 to turn on. Q4’s collector current then provides the base drive for Q3 and Q2, and the output low voltage swing is set by Q2’s VCE,SAT, which is about 5 mV. DRIVING CAPACITIVE LOADS The OP193/OP293 amplifiers are unconditionally stable with capacitive loads less than 200 pF. However, the small signal, unity-gain overshoot improves if a resistive load is added. For example, transient overshoot is 20% when driving a 1000 pF, 10 kΩ load. When driving large capacitive loads in unity-gain configurations, an in-the-loop compensation technique is recommended, as illustrated in Figure 30. I2 I4 Q1 Q2 Q6 Q4 Q7 Q8 Q3 TO OUTPUT STAGE D1 R1A R2A R1B R2B I5 I6 V– NULLING TERMINALS (OP193 ONLY) Figure 26. OP193/OP293 Equivalent Input Circuit Rev. C | Page 13 of 20 00295-025 OP293 ONLY I3 Q5 2kΩ –INPUT I1 00295-026 Q2 V+ 2kΩ OUTPUT Q3 I1 +INPUT Q5 OP193/OP293 OUTPUT PHASE REVERSAL—OP293 The OP293 includes two lateral PNP transistors, Q7 and Q8, to protect against phase reversal. If an input is brought more than one diode drop (≈0.7 V) below ground, Q7 and Q8 combine to level shift the entire cascode stage, including the bias to Q3 and Q4, simultaneously. In this case, Q4 does not saturate and the output remains low. 2 OP293 OP193 1 0 0 1000 2000 3000 4000 5000 6000 7000 HOURS 00295-027 The OP193’s input PNP collector-base junction can be forwardbiased if the inputs are brought more than one diode drop (0.7 V) below ground. When this happens to the noninverting input, Q4 of the cascode stage turns on and the output goes high. If the positive input signal can go below ground, phase reversal can be prevented by clamping the input to the negative supply (that is, GND) with a diode. The reverse leakage of the diode does add to the input bias current of the amplifier. If input bias current is not critical, a 1N914 diode adds less than 10 nA of leakage. However, its leakage current doubles for every 10°C increase in ambient temperature. For critical applications, the collector-base junction of a 2N3906 transistor adds only about 10 pA of additional bias current. To limit the current through the diode under fault conditions, a 1 k Ω resistor isrecommended in series with the input. (The OP193’s internal current limiting resistors do not protect the external diode.) 3 Figure 27. Lithium Sulfur Dioxide Cell Discharge Characteristic with OP193/OP293 and 100 kΩ Loads Input Offset Voltage Nulling The OP193 provides two offset nulling terminals that can be used to adjust the OP193’s internal VOS. In general, operational amplifier terminals should never be used to adjust system offset voltages. The offset nulling circuit of Figure 28 provides about ±7 mV of offset adjustment range. A 100 kΩ resistor placed in series with the wiper arm of the offset null potentiometer, as shown in Figure 29, reduces the offset adjustment range to 400 μV and is recommended for applications requiring high null resolution. Offset nulling does not adversely affect TCVOS performance, providing that the trimming potentiometer temperature coefficient does not exceed ±100 ppm/°C. The OP293 does not exhibit output phase reversal for inputs up to −5 V below V− at +25°C. The phase reversal limit at +125°C is about −3 V. If the inputs can be driven below these levels, an external clamp diode, as discussed in the previous section, should be added. V+ 7 2 OP193 6 4 3 5 1 BATTERY-POWERED APPLICATIONS 100kΩ OP193/OP293 series op amps can be operated on a minimum supply voltage of 1.7 V, and draw only 13 μA of supply current per amplifier from a 2.0 V supply. In many battery-powered circuits, OP193/OP293 devices can be continuously operated for thousands of hours before requiring battery replacement, thus reducing equipment downtime and operating cost. High performance portable equipment and instruments frequently use lithium cells because of their long shelf life, light weight, and high energy density relative to older primary cells. Most lithium cells have a nominal output voltage of 3 V and are noted for a flat discharge characteristic. The low supply voltage requirement of the OP193/OP293, combined with the flat discharge characteristic of the lithium cell, indicates that the Rev. C | Page 14 of 20 V– 00295-028 OUTPUT PHASE REVERSAL—OP193 4 Figure 28. Offset Nulling Circuit V+ 7 2 OP193 6 4 3 5 1 100kΩ 100kΩ V– 00295-029 As previously mentioned, the OP193/OP293 op amps use a PNP input stage with protection resistors in series with the inverting and noninverting inputs. The high breakdown of the PNP transistors, coupled with the protection resistors, provides a large amount of input protection from overvoltage conditions. The inputs can therefore be taken 20 V beyond either supply without damaging the amplifier. OP193/OP293 can be operated over the entire useful life of the cell. Figure 27 shows the typical discharge characteristic of a 1 Ah lithium cell powering the OP193 and OP293, with each amplifier, in turn, driving 2.1 V into a 100 kΩ load. LITHIUM SULFUR DIOXIDE CELL VOLTAGE (V) INPUT OVERVOLTAGE PROTECTION Figure 29. High Resolution Offset Nulling Circuit OP193/OP293 A MICROPOWER FALSE-GROUND GENERATOR Some single-supply circuits work best when inputs are biased above ground, typically at ½ of the supply voltage. In these cases, a false ground can be created by using a voltage divider buffered by an amplifier. One such circuit is shown in Figure 30. V+ (2.5V TO 36V) R2 1.5MΩ R1 240kΩ 7 2 C1 1000pF OP193 3 This circuit generates a false-ground reference at ½ of the supply voltage, while drawing only about 27 μA from a 5 V supply. The circuit includes compensation to allow for a 1 μF bypass capacitor at the false-ground output. The benefit of a large capacitor is that not only does the false ground present a very low dc resistance to the load, but its ac impedance is low as well. The OP193 can both sink and source more than 5 mA, which improves recovery time from transients in the load current. 6 VOUT (1.23V @ 25°C) 5 4 Q2 MAT01AH 1 7 2 Q1 6 + 3 – 5 VBE1 – R3 68kΩ V1 – 5V OR 12V + VBE2 ΔVBE + R4 130kΩ 00295-031 R5, 20kΩ OUTPUT ADJUST 10kΩ + 0.022µF Figure 31. A Battery-Powered Voltage Reference 240kΩ 3 + 240kΩ 1µF 4 6 A SINGLE-SUPPLY CURRENT MONITOR 100Ω 2.5V OR 6V + 1µF Figure 30. A Micropower False-Ground Generator A BATTERY-POWERED VOLTAGE REFERENCE The circuit of Figure 31 is a battery-powered voltage reference that draws only 17 μA of supply current. At this level, two AA alkaline cells can power this reference for more than 18 months. At an output voltage of 1.23 V at 25°C, drift of the reference is only 5.5 μV/°C over the industrial temperature range. Load regulation is 85 μV/mA with line regulation at 120 μV/V. Design of the reference is based on the Brokaw band gap core technique. Scaling of Resistor R1 and Resistor R2 produces unequal currents in Q1 and Q2. The resulting ΔVBE across R3 creates a temperature-proportional voltage (PTAT), which, in turn, produces a larger temperature-proportional voltage across R4 and R5, V1. The temperature coefficient of V1 cancels (first order) the complementary to absolute temperature (CTAT) coefficient of VBE1. When adjusted to 1.23 V at 25°C, output voltage temperature coefficient is at a minimum. Band gap references can have start-up problems. With no current in R1 and R2, the OP193 is beyond its positive input range limit and has an undefined output state. Shorting Pin 5 (an offset adjust pin) to ground forces the output high under these circumstances and ensures reliable startup without significantly degrading the OP193’s offset drift. Current monitoring essentially consists of amplifying the voltage drop across a resistor placed in series with the current to be measured. The difficulty is that only small voltage drops can be tolerated, and with low precision op amps, this greatly limits the overall resolution. The single-supply current monitor of Figure 32 has a resolution of 10 μA and is capable of monitoring 30 mA of current. This range can be adjusted by changing the current sense resistor, R1. When measuring total system current, it may be necessary to include the supply current of the current monitor, which bypasses the current sense resistor, in the final result. This current can be measured and calibrated (together with the residual offset) by adjustment of the offset trim potentiometer, R2. This produces a deliberate temperature dependent offset. However, the supply current of the OP193 is also proportional to temperature, and the two effects tend to track. Voltage developed at the noninverting input and amplified by (1 + R4/R5) appears at VOUT. V+ + TO CIRCUIT UNDER TEST – 7 3 OP193 ITEST 6 4 2 5 VOUT = 100mV/mA(I TEST ) 1 R4 9.9kΩ R1 1Ω R2 100kΩ R5 100Ω R3 100kΩ Figure 32. Single-Supply Current Monitor Rev. C | Page 15 of 20 00295-032 OP193 00295-030 2 7 OP193/OP293 A SINGLE-SUPPLY INSTRUMENTATION AMPLIFIER R1 20kΩ Designing a true single-supply instrumentation amplifier with zero-input and zero-output operation requires special care. The traditional configuration, shown in Figure 33, depends upon Amplifier A1’s output being at 0 V when the applied commonmode input voltage is at 0 V. Any error at the output is multiplied by the gain of A2. In addition, current flows through Resistor R3 as A2’s output voltage increases. A1’s output must remain at 0 V while sinking the current through R3, or a gain error results. With a maximum output voltage of 4 V, the current through R3 is only 2 μA, but this still produces an appreciable error. 5V –IN 5V 10kΩ 5V Q2 V+ A2 1/2 OP293 – VN2222 + +IN R2 1.98MΩ V– Figure 34. An Improved Single-Supply, 0 VIN, 0 VOUT Instrumentation Amplifier R3 20kΩ V+ – A1 1/2 OP293 + V– A LOW POWER, TEMPERATURE TO 4 mA TO 20 mA TRANSMITTER R4 1.98MΩ 5V V+ A2 1/2 OP293 – + +IN A simple temperature to 4 mA to 20 mA transmitter is shown in Figure 35. After calibration, this transmitter is accurate to ±0.5°C over the −50°C to +150°C temperature range. The transmitter operates from 8 V to 40 V with supply rejection better than 3 ppm/V. One half of the OP293 is used to buffer the TEMP pin, and the other half regulates the output current to satisfy the current summation at its noninverting input. VOUT 00295-033 ISINK V– Figure 33. A Conventional Instrumentation Amplifier One solution to this problem is to use a pull-down resistor. For example, if R3 = 20 kΩ, then the pull-down resistor must be less than 400 Ω. However, the pull-down resistor appears as a fixed load when a common-mode voltage is applied. With a 4 V common-mode voltage, the additional load current is 10 mA, which is unacceptable in a low power application. I OUT + VTEMP × (R6 + R7 ) R2 × R10 R2 + R6 + R7 − VSET R2 × R10 The change in output current with temperature is the derivative of the following transfer function: Figure 34 shows a better solution. A1’s sink current is provided by a pair of N-channel FET transistors, configured as a current mirror. With the values shown, the sink current of Q2 is about 340 μA. Thus, with a common-mode voltage of 4 V, the additional load current is limited to 340 μA vs. 10 mA with a 400 Ω resistor. ∆I OUT ∆T ∆VTEMP (R6 + R7 ) = ∆T R2 × R10 1N4002 V+ 8V TO 40V SPAN TRIM R4 20kΩ REF43GPZ 2 VIN 2 GND 4 8 – 1/2 VOUT 6 TEMP 3 VOUT 00295-034 Q1 5V –IN R4 1.98MΩ R3 20kΩ V+ A1 1/2 OP293 + V– – 3 R1, 10kΩ 1 R2 VTEMP 1kΩ R6 3kΩ R7 5kΩ 6 OP293 – + OP293 4 1/2 R3 100kΩ R5 5kΩ VSET 5 + ZERO TRIM 7 R8 1kΩ 2N1711 R9 100kΩ R10 100Ω 1%, 1/2 W IOUT NOTES 1. ALL RESISTORS 1/4 W, 5% UNLESS OTHERWISE NOTED. Figure 35. Temperature to 4 mA to 20 mA Transmitter Rev. C | Page 16 of 20 RLOAD 00295-035 R1 20kΩ R2 1.98MΩ OP193/OP293 From the formulas, it can be seen that if the span trim is adjusted before the zero trim, the two trims are not interactive, which greatly simplifies the calibration procedure. Calibration of the transmitter is simple. First, the slope of the output current vs. temperature is calibrated by adjusting the span trim, R7. A couple of iterations may be required to be sure the slope is correct. C1 75nF R1 200kΩ 3 R2 200kΩ – A1 1/2 OP293 + R4 200kΩ 1 6 4 (TAMBIENT − TMIN ) + 4 mA – A2 1/2 OP293 7 SQUARE OUT + TRIANGLE OUT R6 200kΩ R7 200kΩ R8 200kΩ The zero trim can be set at any known temperature by adjusting R5 until the output current equals: 5V CD4066 1 IN/OUT VDD 14 5V S1 Table 7 shows the values of R6 required for various temperature ranges. Table 7. R6 Values vs. Temperature Temp Range 0°C to 70°C −40°C to +85°C −55°C to +150°C 8 5 When the span trim has been adjusted, the zero trim can be made. Adjusting the zero trim does not affect the gain. ∆I FS I OUT = ∆TOPERATING R5 200kΩ 5V 2 VCONTROL R3 100kΩ 5V R6 10 kΩ 6.2 kΩ 3 kΩ 2 OUT/IN 3 OUT/IN 4 IN/OUT 5 CONT 6 CONT CONT 13 S2 CONT 12 IN/OUT 11 S3 OUT/IN 10 OUT/IN 9 5V S4 7 IN/OUT 8 00295-036 A MICROPOWER VOLTAGE CONTROLLED OSCILLATOR VSS The OP293 CMOS analog switch forms the precision VCO of Figure 36. This circuit provides triangle and square wave outputs and draws only 50 μA from a single 5 V supply. A1 acts as an integrator; S1 switches the charging current symmetrically to yield positive and negative ramps. The integrator is bounded by A2, which acts as a Schmitt trigger with a precise hysteresis of 1.67 V, set by Resistor R5, Resistor R6, and Resistor R7, and associated CMOS switches. The resulting output of A1 is a triangle wave with upper and lower levels of 3.33 V and 1.67 V. The output of A2 is a square wave with almost rail-to-rail swing. With the components shown, frequency of operation is given by the equation: fOUT = VCONTROL V × 10 Hz/V However, the frequency can easily be changed by varying C1. The circuit operates well up to 500 Hz. Rev. C | Page 17 of 20 Figure 36. Micropower Voltage Controlled Oscillator OP193/OP293 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 1 5 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 6.20 (0.2441) 5.80 (0.2284) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) 0.50 (0.0196) 0.25 (0.0099) 45° 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) COMPLIANT TO JEDEC STANDARDS MS-012-A A CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS (IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN. 012407-A 8 4.00 (0.1574) 3.80 (0.1497) Figure 37. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model OP193FS OP193FS-REEL OP193FS-REEL7 OP193FSZ1 OP193FSZ-REEL1 OP193FSZ-REEL71 OP293ES OP293ES-REEL OP293ES-REEL7 OP293ESZ1 OP293ESZ-REEL1 OP293ESZ-REEL71 OP293FS OP293FS-REEL OP293FS-REEL7 OP293FSZ1 OP293FSZ-REEL1 OP293FSZ-REEL71 1 Temperature Range −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C −40°C to +125°C Package Description 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N Z = RoHS Compliant Part. Rev. C | Page 18 of 20 Package Option S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) S-Suffix (R-8) OP193/OP293 NOTES Rev. C | Page 19 of 20 OP193/OP293 NOTES ©1995–2009 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D00295-0-9/09(C) Rev. C | Page 20 of 20