Micropower RRIO Operational Amplifier ADA4092-4 PIN CONFIGURATION Single-supply operation: 2.7 V to 36 V Wide input voltage range Rail-to-rail output swing Low supply current: 200 µA/amplifier Wide bandwidth: 1.4 MHz High phase margin: 69° Slew rate: 0.4 V/µs Low offset voltage: 1.50 mV maximum No phase reversal Overvoltage protection (OVP) 25 V above/below supply rails at ±5 V 12 V above/below supply rails at ±15 V 14 OUTD –INA 2 13 –IND +INA 3 ADA4092-4 12 +IND TOP VIEW (Not to Scale) 11 –V +INB 5 10 +INC –INB 6 9 –INC OUTB 7 8 OUTC OUTA 1 +V 4 08803-001 FEATURES Figure 1. 14-Lead TSSOP (RU-14) APPLICATIONS Industrial process control Battery-powered instrumentation Power supply control and protection Telecommunications Remote sensors Low voltage strain gage amplifiers DAC output amplifiers GENERAL DESCRIPTION The ADA4092-4 quad is a micropower, single-supply, 1.4 MHz bandwidth amplifier featuring rail-to-rail inputs and outputs. It is guaranteed to operate from a +2.7 V to +30 V single supply as well as from ±1.35 V to ±15 V dual supplies. The ADA4092-4 is specified over the extended industrial temperature range of −40°C to +125°C. The ADA4092-4 is part of the growing selection of 36 V, low power op amps from Analog Devices, Inc., see Table 1. The ADA4092-4 features a unique input stage that allows the input voltage to exceed either supply safely without any phase reversal or latch-up; this is called overvoltage protection (OVP). The ADA4092-4 is available in the 14–lead TSSOP surface-mount package. Applications for these amplifiers include portable telecommunications equipment, power supply control and protection, and interface for transducers with wide output ranges. Sensors requiring a rail-to-rail input amplifier include Hall effect, piezoelectric, and resistive transducers. Table 1. Low Power, 36 V Operational Amplifiers Family Single Dual Quad Rail-to-Rail I/O RRIO Precision PJFET ADA4092-4 ADA4091-2 ADA4091-4 AD8682 AD8684 Low Noise OP1177 OP2177 OP4177 The ability to swing rail-to-rail at both the input and output enables designers, for example, to build multistage filters in single-supply systems and to maintain high signal-to-noise ratios (SNR). Rev. A 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. 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ADA4092-4 TABLE OF CONTENTS Features .............................................................................................. 1 ESD Caution...................................................................................6 Applications ....................................................................................... 1 Typical Performance Characteristics ..............................................7 Pin Configuration ............................................................................. 1 Theory of Operation ...................................................................... 15 General Description ......................................................................... 1 Input Stage ................................................................................... 15 Revision History ............................................................................... 2 Output Stage................................................................................ 15 Specifications..................................................................................... 3 Input Overvoltage Protection ................................................... 16 Electrical Specifications ............................................................... 3 Comparator Operation .............................................................. 16 Absolute Maximum Ratings ............................................................ 6 Outline Dimensions ....................................................................... 17 Thermal Resistance ...................................................................... 6 Ordering Guide .......................................................................... 17 REVISION HISTORY 5/10—Rev. 0 to Rev. A Changes to Data Sheet Title, General Description, and Table 1 ......................................................................................... 1 4/10—Revision 0: Initial Version Rev. A | Page 2 of 20 ADA4092-4 SPECIFICATIONS ELECTRICAL SPECIFICATIONS VSY = ±1.5 V, VCM = 0 V, TA = 25°C, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Symbol Test Conditions/Comments Min Typ Max Unit −1.5 −2.5 +0.2 −40°C ≤ TA ≤ +125°C +1.5 +2.5 mV mV µV/°C nA nA nA nA nA nA V dB dB dB dB dB dB VOS ΔVOS/ΔT IB −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio IVR CMRR Large Signal Voltage Gain AVO OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Limit Closed-Loop Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Voltage Noise Density VOH VOL ISC ZOUT PSRR ISY VCM = −1.5 V to +1.5 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = −1.2 V to +1.2 V −40°C ≤ TA ≤ +125°C RL = 10 kΩ, VO = −1.2 V to +1.2 V −40°C ≤ TA ≤ +125°C −60 −60 −275 −4 −5 −75 −1.5 70 68 106 101 92 85 RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C to +125°C RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C ≤ TA ≤ +125°C Source/sink f = 1 MHz, AV = +1 1.485 1.480 1.470 1.455 VSY = 2.7 V to 36 V −40°C ≤ TA ≤ +125°C IO = 0 mA −40°C ≤ TA ≤ +125°C 98 90 3 −45 +1 +60 +275 +4 +5 +75 +1.5 85 113 94 1.495 1.480 −1.497 −1.495 −1.490 −1.480 −1.485 −1.475 ±30 130 112 165 200 300 V V V V V V V V mA Ω dB dB µA µA SR tS GBP ΦM RL = 100 kΩ, CL = 30 pF To 0.01% 0.4 25 1.2 66 V/µs µs MHz Degrees en p-p en 0.1 Hz to 10 Hz f = 1 kHz 0.8 30 µV p-p nV/√Hz Rev. A | Page 3 of 20 ADA4092-4 VSY = ±5.0 V, VCM = 0 V, TA = 25°C, unless otherwise noted. Table 3. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Symbol Test Conditions/Comments Min Typ Max Unit −1.5 −2.5 +0.2 −40°C ≤ TA ≤ +125°C +1.5 +2.5 mV mV µV/°C nA nA nA nA nA nA V dB dB dB dB dB dB VOS ΔVOS/ΔT IB −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio IVR CMRR Large Signal Voltage Gain AVO OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Limit Closed-Loop Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Voltage Noise Density VOH VOL ISC ZOUT PSRR ISY VCM = −5.0 V to +5.0 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = ±4.7 V −40°C ≤ TA ≤ +125°C RL = 10 kΩ, VO = ±4.7 V −40°C ≤ TA ≤ +125°C −60 −80 −350 −4 −7 −100 −5 82 78 113 106 98 90 RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C ≤ TA ≤ +125°C Source/sink f = 1 MHz, AV = +1 4.980 4.975 4.945 4.900 VSY = 2.7 V to 36 V −40°C ≤ TA ≤ +125°C IO = 0 mA −40°C ≤ TA ≤ +125°C 98 90 3 −53 +1 +80 +350 +4 +7 +100 +5 95 117 100 4.990 4.960 −4.997 −4.990 −4.990 −4.980 −4.980 −4.975 ±20 90 112 180 225 300 V V V V V V V V mA Ω dB dB µA µA SR tS GBP ΦM RL = 100 kΩ, CL = 30 pF To 0.01% 0.4 25 1.3 67 V/µs µs MHz Degrees en p-p en 0.1 Hz to 10 Hz f = 1 kHz 0.8 30 µV p-p nV/√Hz Rev. A | Page 4 of 20 ADA4092-4 VSY = ±15.0 V, VCM = 0 V, VO = 0 V, TA = 25°C, unless otherwise noted. Table 4. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Symbol Test Conditions/Comments Min Typ Max Unit −1.5 −2.5 +0.2 −40°C ≤ TA ≤ +125°C +1.5 +2.5 mV mV µV/°C nA nA nA nA nA nA V dB dB dB dB dB dB VOS ΔVOS/ΔT IB −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio IVR CMRR Large Signal Voltage Gain AVO OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Short-Circuit Limit Closed-Loop Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin Channel Separation NOISE PERFORMANCE Voltage Noise Voltage Noise Density VOH VOL ISC ZOUT PSRR ISY VCM = −15.0 V to +15.0 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = ±14.7 V −40°C ≤ TA ≤ +125°C RL = 10 kΩ, VO = ±14.7 V −40°C ≤ TA ≤ +125°C −60 −80 −500 −4 −10 −140 −15 90 87 116 108 102 93 RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 100 kΩ to GND −40°C ≤ TA ≤ +125°C RL = 10 kΩ to GND −40°C ≤ TA ≤ +125°C Source/sink f = 1 MHz, AV = +1 14.970 14.950 14.900 14.800 VSY = 2.7 V to 36 V −40°C ≤ TA ≤ +125°C IO = 0 mA −40°C ≤ TA ≤ +125°C 98 90 SR tS GBP ΦM CS RL = 100 kΩ, CL = 30 pF To 0.01% en p-p en 3 −50 +1 +80 +500 +4 +10 +140 +15 103 118 104 14.980 14.915 −14.985 −14.970 −14.980 −14.965 −14.950 −14.940 ±20 68 112 200 250 350 V V V V V V V V mA Ω dB dB µA µA f = 1 kHz 0.4 25 1.4 69 100 V/µs µs MHz Degrees dB 0.1 Hz to 10 Hz f = 1 kHz 0.8 30 µV p-p nV/√Hz Rev. A | Page 5 of 20 ADA4092-4 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 5. Parameter Supply Voltage Input Voltage Differential Input Voltage Input Current Output Short-Circuit Duration to GND Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature (Soldering, 60 sec) Rating 36 V Refer to the Input Overvoltage Protection section ±VSY ±5 mA Indefinite −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C θJA is specified for the device soldered on a 4-layer JEDEC standard printed circuit board (PCB) with zero airflow. Table 6. Thermal Resistance Package Type 14-Lead TSSOP (RU-14) ESD CAUTION 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. Rev. A | Page 6 of 20 θJA 112 θJC 35 Unit °C/W ADA4092-4 TYPICAL PERFORMANCE CHARACTERISTICS 180 40 100 80 60 40 30 25 20 15 10 1200 OFFSET VOLTAGE (µV) –2 –1 Figure 2. Input Offset Voltage Distribution, 3 V 1 2 3 4 TCVOS (μV/°C) 5 6 7 8 6 7 8 6 7 8 Figure 5. TCVOS Distribution, 3 V 180 70 ADA4092-4 VSY = ±5V TA = 25°C 160 ADA4092-4 VSY = ±5V TA = 25°C 60 NUMBER OF AMPLIFIERS 140 NUMBER OF PARTS 0 08803-002 800 1000 600 400 200 0 –200 –400 –600 0 –800 0 –1000 5 –1200 20 08803-005 120 08803-006 NUMBER OF AMPLIFIERS NUMBER OF PARTS 140 ADA4092-4 VSY = ±1.5V TA = 25°C 35 08803-007 ADA4092-4 VSY = ±1.5V TA = 25°C 160 120 100 80 60 50 40 30 20 40 10 20 0 1200 OFFSET VOLTAGE (µV) –2 –1 1 2 3 4 TCVOS (μV/°C) 5 Figure 6. TCVOS Distribution, 10 V Figure 3. Input Offset Voltage Distribution, 10 V 70 180 ADA4092-4 VSY = ±15V TA = 25°C 160 ADA4092-4 VSY = ±15V TA = 25°C 60 NUMBER OF AMPLIFIERS 140 120 100 80 60 50 40 30 20 40 10 20 1200 –2 08803-004 800 OFFSET VOLTAGE (µV) 1000 600 400 200 0 –200 –400 –600 –800 –1000 0 –1200 NUMBER OF PARTS 0 08803-003 800 1000 600 400 200 0 –200 –400 –600 –800 –1000 –1200 0 –1 0 1 2 3 4 TCVOS (μV/°C) 5 Figure 7. TCVOS Distribution, 30 V Figure 4. Input Offset Voltage Distribution, 30 V Rev. A | Page 7 of 20 ADA4092-4 60 600 500 40 20 ADA4092-4 VSY = ±1.5V TA = 25°C 300 IB (nA) VOS (µV) 400 ADA4092-4 VSY = ±1.5V T = 25°C IOS IB– 0 200 –20 100 –1.0 –0.5 0 0.5 1.0 1.5 VCM (V) –40 –1.5 08803-008 0 –1.5 –1.0 –0.5 0 0.5 1.0 1.5 VCM (V) Figure 8. Input Offset Voltage vs. Common-Mode Voltage, 3 V Figure 11. Input Bias Current vs. Common-Mode Voltage, 3 V 600 60 500 08803-011 IB+ ADA4092-4 VSY = ±5V T = 25°C 40 20 IB (nA) VOS (µV) 400 300 0 ADA4092-4 VSY = ±5V TA = 25°C 200 IOS IB– –20 100 –4 –3 –2 –1 0 1 VCM (V) 2 3 4 5 –40 –5 08803-009 0 –5 –3 –2 –1 0 1 2 3 4 5 VCM (V) Figure 12. Input Bias Current vs. Common-Mode Voltage, 10 V Figure 9. Input Offset Voltage vs. Common-Mode Voltage, 10 V 60 600 500 40 400 20 ADA4092-4 VSY = ±15V TA = 25°C 300 IB (nA) VOS (µV) –4 08803-012 IB+ ADA4092-4 VSY = ±15V T = 25°C IOS IB– 0 200 –5 0 5 10 15 VCM (V) –40 –15 –10 –05 0 5 10 15 VCM (V) Figure 10. Input Offset Voltage vs. Common-Mode Voltage, 30 V Figure 13. Input Bias Current vs. Common-Mode Voltage, 30 V Rev. A | Page 8 of 20 08803-013 –10 08803-010 0 –15 IB+ –20 100 ADA4092-4 120 10k ADA4092-4 VSY = ±1.5V TA = 25°C GAIN (dB) AND PHASE (Degrees) 100 100 VDD – VOH VOL – VSS 10 PHASE 80 60 40 GAIN 20 0 –20 ADA4092-4 VSY = ±1.5V TA = 25°C –40 –60 0.1 1 10 100 LOAD CURRENT (mA) 1k 1M 10M Figure 17. Open-Loop Gain and Phase vs. Frequency, 3 V 120 10k ADA4092-4 VSY = ±5V TA = 25°C 100 VDD – VOH VOL – VSS 10 PHASE 80 60 40 GAIN 20 0 –20 –40 ADA4092-4 VSY = ±5V TA = 25°C –60 –80 0.01 0.1 1 10 100 LOAD CURRENT (mA) –100 08803-015 1 0.001 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 15. Dropout Voltage vs. Load Current, 10 V 08803-018 GAIN (dB) AND PHASE (Degrees) 100 1k VOUT TO RAIL (mV) 100k FREQUENCY (Hz) Figure 14. Dropout Voltage vs. Load Current, 3 V Figure 18. Open-Loop Gain and Phase vs. Frequency, 10 V 140 10k ADA4092-4 VSY = ±15V TA = 25°C GAIN (dB) AND PHASE (Degrees) 120 1k 100 VDD – VOH VOL – VSS 10 100 PHASE 80 60 40 GAIN 20 0 –20 ADA4092-4 VSY = ±15V TA = 25°C –40 –60 1 0.001 –80 0.01 0.1 1 10 LOAD CURRENT (mA) 100 08803-016 VOUT TO RAIL (mV) 10k 08803-017 0.01 08803-014 –80 1 0.001 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 16. Dropout Voltage vs. Load Current, 30 V Figure 19. Open-Loop Gain and Phase vs. Frequency, 30 V Rev. A | Page 9 of 20 08803-019 VOUT TO RAIL (mV) 1k ADA4092-4 50 ADA4092-4 VSY = ±1.5V TA = 25°C 100 30 GAIN = +10 ZOUT (Ω) 20 10 AV = +100 10 AV = +10 GAIN = +1 0 1 AV = +1 –10 0.1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 10 08803-020 –20 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 08803-023 CLOSED-LOOP GAIN (dB) 1k ADA4092-4 VSY = ±1.5V TA = 25°C GAIN = +100 40 Figure 23. Closed-Loop Output Impedance vs. Frequency, 3 V Figure 20. Closed-Loop Gain vs. Frequency, 3 V 50 ADA4092-4 VSY = ±5V TA = 25°C 100 30 GAIN = +10 ZOUT (Ω) 20 10 AV = +100 10 AV = +10 GAIN = +1 0 1 0.1 10 100 1k 10k 100k 1M 10M FREQUENCY (Hz) 10 08803-021 –20 1k 10k 100k 1M 10M FREQUENCY (Hz) Figure 21. Closed-Loop Gain vs. Frequency, 10 V Figure 24. Closed-Loop Output Impedance vs. Frequency, 10 V 50 1k ADA4092-4 VSY = ±15V TA = 25°C GAIN = +100 40 ADA4092-4 VSY = ±15V TA = 25°C 100 30 GAIN = +10 ZOUT (Ω) 20 10 AV = +100 10 AV = +10 GAIN = +1 0 1 AV = +1 –10 –20 10 100 1k 10k 100k 1M FREQUENCY (Hz) 10M 08803-022 CLOSED-LOOP GAIN (dB) 100 08803-024 AV = +1 –10 Figure 22. Closed-Loop Gain vs. Frequency, 30 V 0.1 10 100 1k 10k 100k 1M FREQUENCY (Hz) Figure 25. Output Impedance vs. Frequency, 30 V Rev. A | Page 10 of 20 10M 08803-025 CLOSED-LOOP GAIN (dB) 1k ADA4092-4 VSY = ±5V TA = 25°C GAIN = +100 40 ADA4092-4 90 120 80 100 70 80 PSRR+ PSRR (dB) CMRR (dB) 60 50 40 30 ADA4092-4 VSY = ±1.5V TA = 25°C 60 40 PSRR– 20 1k 10k 100k 1M 10M FREQUENCY (Hz) –20 100 08803-026 0 100 1k 10k 100k 1M 10M 08803-029 10 ADA4092-4 VSY = ±1.5V TA = 25°C 1M 10M 08803-030 0 10M 08803-031 20 FREQUENCY (Hz) Figure 29. PSRR vs. Frequency, 3 V Figure 26. CMRR vs. Frequency, 3 V 120 100 90 100 80 80 60 PSRR (dB) CMRR (dB) 70 50 40 ADA4092-4 VSY = ±5V TA = 25°C 30 40 PSRR– 20 20 0 10 1k 10k 100k 1M 10M FREQUENCY (Hz) –20 100 08803-027 0 100 PSRR+ 60 ADA4092-4 VSY = ±5V TA = 25°C 1k 10k 100k FREQUENCY (Hz) Figure 30. PSRR vs. Frequency, 10 V Figure 27. CMRR vs. Frequency, 10 V 120 100 90 100 80 80 PSRR (dB) 60 50 40 ADA4092-4 VSY = ±15V TA = 25°C 30 60 PSRR– 40 20 0 10 0 100 PSRR+ 20 1k 10k 100k 1M FREQUENCY (Hz) 10M 08803-028 CMRR (dB) 70 –20 100 ADA4092-4 VSY = ±15V TA = 25°C 1k 10k 100k 1M FREQUENCY (Hz) Figure 31. PSRR vs. Frequency, 30 V Figure 28. CMRR vs. Frequency, 30 V Rev. A | Page 11 of 20 ADA4092-4 2.0 0.06 1.5 0.04 1.0 0.02 0 ADA4092-4 VSY = ±1.5V TA = 25°C RL = 100kΩ CL = 100pF –1.0 –0.04 –1.5 0 20 10 40 30 50 60 70 80 TIME (µs) –0.06 08803-032 –2.0 ADA4092-4 VSY = ±1.5V TA = 25°C RL = 100kΩ CL = 100pF –0.02 0 6 0.06 4 0.04 2 0.02 0 ADA4092-4 VSY = ±5V TA = 25°C RL = 100kΩ CL = 100pF 60 100 80 120 140 160 TIME (µs) –0.06 08803-033 –6 40 10 12 14 16 18 16 18 ADA4092-4 VSY = ±5V TA = 25°C RL = 100kΩ CL = 100pF –0.04 20 8 0 –0.02 –4 0 6 Figure 35. Small Signal Transient Response, 3 V VOUT (V) VOUT (V) 4 TIME (µs) Figure 32. Large Signal Transient Response, 3 V –2 2 0 2 4 6 8 10 12 14 TIME (µs) Figure 33. Large Signal Transient Response, 10 V 08803-036 –0.5 0 08803-035 VOUT (V) VOUT (V) 0.5 Figure 36. Small Signal Transient Response, 10 V 2.0 0.06 1.5 0.04 1.0 0.02 ADA4092-4 VSY = ±15V TA = 25°C RL = 100kΩ CL = 100pF –0.5 –1.0 0 ADA4092-4 VSY = ±15V TA = 25°C RL = 100kΩ CL = 100pF –0.02 –0.04 –1.5 –2.0 0 40 80 120 160 TIME (µs) 200 Figure 34. Large Signal Transient Response, 30 V –0.06 0 2 4 6 8 10 12 14 16 TIME (µs) Figure 37. Small Signal Transient Response, 30 V Rev. A | Page 12 of 20 18 08803-037 VOUT (V) 0 08803-034 VOUT (V) 0.5 1.4 –0.2 1.2 –0.4 1.0 –0.6 0.8 ADA4092-4 VSY = ±1.5V TA = 25°C 0.6 –0.8 –1.0 0.4 –1.2 0.2 –1.4 0 0 10 20 30 40 ADA4092-4 VSY = ±1.5V TA = 25°C 60 50 70 80 90 TIME (µs) –1.6 0 10 20 40 30 60 50 70 90 80 100 TIME (µs) Figure 38. Positive Overload Recovery, 3 V 08803-041 0 VOUT (V) 1.6 08803-038 VOUT (V) ADA4092-4 Figure 41. Negative Overload Recovery, 3 V 6 0 5 –1 4 VOUT (V) VOUT (V) –2 3 ADA4092-4 VSY = ±5V TA = 25°C 2 –3 ADA4092-4 VSY = ±5V TA = 25°C –4 1 0 10 20 30 50 40 60 90 70 TIME (µs) –6 08803-039 –1 0 10 20 30 50 40 60 80 70 90 TIME (µs) Figure 39. Positive Overload Recovery, 10 V 08803-042 –5 0 Figure 42. Negative Overload Recovery, 10 V 16 0 14 –2 12 –4 10 VOUT (V) ADA4092-4 VSY = ±15V TA = 25°C 6 4 ADA4092-4 VSY = ±15V TA = 25°C –12 2 0 10 20 30 40 50 60 70 TIME (µs) 80 90 Figure 40. Positive Overload Recovery, 30 V –16 0 10 20 30 40 50 60 70 TIME (µs) Figure 43. Negative Overload Recovery, 30 V Rev. A | Page 13 of 20 80 08803-043 –14 0 –2 –8 –10 08803-040 VOUT (V) –6 8 ADA4092-4 0.5 1000 ADA4092-4 VSY = ±15V TA = 25°C 0.4 ADA4092-4 VSY = ±15V T = 25°C 0.3 en (nV/√Hz) VOUT (µV) 0.2 0.1 0 100 –0.1 –0.2 1 2 3 4 6 5 7 8 9 10 TIME (µs) 10 0.01 10 100 1000 50k Figure 46. Voltage Noise Density 200 –50 180 –60 CHANNEL SEPARATION (dB) 160 140 120 100 80 ADA4092-4 TA = 25°C 40 –70 –80 –90 –100 –110 –120 ADA4092-4 VSY = ±1.5V, ±5V, ±15V TA = 25°C –130 20 0 –140 0 4 8 12 16 20 24 28 VSUPPLY (V) 32 36 08803-045 ISUPPLY (µA) 1 FREQUENCY (Hz) Figure 44. Peak-to-Peak Voltage Noise 60 0.10 08803-046 0 08803-044 –0.4 08803-047 –0.3 20 100 1k 10k FREQUENCY (Hz) Figure 47. Channel Separation vs. Frequency Figure 45. Supply Current vs. Supply Voltage Rev. A | Page 14 of 20 ADA4092-4 THEORY OF OPERATION A common practice in bipolar amplifiers to protect the input transistors from large differential voltages is to include series resistors and differential diodes. See Figure 49 for the full input protection circuitry. These diodes turn on whenever the differential voltage exceeds approximately 0.6 V. In this condition, current flows between the input pins, limited only by the two 5 kΩ resistors. Evaluate each application carefully to make sure that the increase in current does not affect performance. The ADA4092-4 is a single-supply, micropower amplifier featuring rail-to-rail inputs and outputs. To achieve wide input and output ranges, these amplifiers employ unique input and output stages. INPUT STAGE In Figure 48, the input stage comprises two differential pairs, a PNP pair (PNP input stage) and an NPN pair (NPN input stage). These input stages do not work in parallel. Instead, only one stage is on for any given input common-mode signal level. The PNP stage (Transistor Q1 and Transistor Q2) is required to ensure that the amplifier remains in the linear region when the input voltage approaches and reaches the negative rail. Alternatively, the NPN stage (Transistor Q5 and Transistor Q6) is needed for input voltages up to, and including, the positive rail. OUTPUT STAGE The output stage in the ADA4092-4 device uses a PNP and an NPN transistor, as do most output stages. However, Q32 and Q33, the output transistors, connect with their collectors to an output pin to achieve the rail-to-rail output swing. As the output voltage approaches either the positive or the negative rail, these transistors begin to saturate. Thus, the final limit on output voltage is the saturation voltage of these transistors, which is about 50 mV. The output stage has inherent gain arising from the transistor output impedance, as well as any external load impedance; consequently, the open-loop gain of the op amp is dependent on the load resistance and decreases when the output voltage is close to either rail. For the majority of the input common-mode range, the PNP stage is active, as shown in Figure 8 through Figure 13. Notice that the VOS shifts and that the bias current switches direction at approximately 1.5 V below the positive rail. At voltages below this level, the bias current flows out of the ADA4092-4 input, from the PNP input stage. However, above this voltage, the bias current enters the device due to the NPN stage. The actual mechanism within the amplifier for switching between the input stages comprises Q3, Q4, and Q7. As the input common-mode voltage increases, the emitters of Q1 and Q2 follow that voltage plus a diode drop. Eventually, the emitters of Q1 and Q2 are high enough to turn on Q3, which diverts the tail current away from the PNP input stage, turning it off. The tail current of the PNP pair is diverted to the Q4/Q7 current mirror to activate the NPN input stage, as shown in Figure 48. –IN Q32 Q3 Q16 Q5 Q6 Q1 Q2 Q8 Q10 Q12 Q17 Q14 OUT Q9 Q11 Q13 Q15 Q18 Q4 Q19 Q33 08803-124 +IN Q7 Figure 48. Simplified Schematic Without Input Protection (See Figure 49) Rev. A | Page 15 of 20 ADA4092-4 INPUT OVERVOLTAGE PROTECTION The ADA4092-4 has two different ESD circuits for enhanced protection, as shown in Figure 49. +V D3 R1 D7 R2 D8 D6 D1 D2 D5 D4 Additional resistance can be added externally in series with each input to protect against higher peak voltages; however, the additional thermal noise of the resistors must be considered. 08803-123 –V Figure 49. Complete Input Protection Network One circuit is a series resistor of 5 kΩ to the internal inputs and diodes (D1 and D2 or D5 and D6) from the internal inputs to the supply rails. The other protection circuit is a circuit with two DIACs (D3 and D4 or D7 and D8) to the supply rails. A DIAC can be considered a bidirectional Zener diode with a transfer characteristic, as shown in Figure 50. 5 4 3 CURRENT (mA) Therefore, consider two conditions to determine which case is the limiting factor. 1. Consider, for example, that when operating on ±15 V, the inputs can go +42 V above the negative supply rail. With the −V pin equal to −15 V, +42 V above this supply (the negative supply) is +27 V. 2. There is a restriction on the input current of 5 mA through a 5 kΩ resistor to the ESD structure to the positive rail. In the first condition, +27 V through the 5 kΩ resistor to +15 V gives a current of 2.4 mA. Thus, the DIAC is the limiting factor. If the ADA4092-4 supply voltages are changed to ±5 V, then −5 V + 42 V = +37 V. However, +5 V + (5 kΩ × 5 mA) = 30 V. Thus, the normal resistor diode structure is the limitation when running on lower supply voltages. 2 1 0 –1 –2 The flatband voltage noise of the ADA4092-4 is approximately 25 nV/√Hz, and a 5 kΩ resistor has a noise of 9 nV/√Hz. Adding an additional 5 kΩ resistor increases the total noise by less than 15% root sum square (rss). Therefore, maintain resistor values below this value (5 kΩ) when overall noise performance is critical. Note that this represents input protection under abnormal conditions only. The correct amplifier operation input voltage range (IVR) is specified in Table 2, Table 3, and Table 4. COMPARATOR OPERATION Although op amps are quite different from comparators, occasionally an unused section of a dual or a quad op amp can be pressed into service as a comparator; however, this is not recommended. For rail-to-rail output op amps, the output stage is generally a ratioed current mirror with bipolar or MOSFET transistors. With the part operating open loop, the second stage increases the current drive to the ratioed mirror to close the loop, but it cannot, which results in an increase in supply current. With three of the op amps operating normally and the fourth one in comparator mode, the supply current increases by about 200 µA (see Figure 51). 1000 ONE COMPARATOR, VOUT HIGH –30 –20 –10 0 10 20 30 VOLTAGE (V) 40 50 900 ONE COMPARATOR, VOUT LOW 800 Figure 50. DIAC Transfer Characteristic 700 NORMAL OPERATION 600 ISY (µA) For a worst-case design analysis, consider two cases. The ADA4092-4 has a normal ESD structure from the internal op amp inputs to the supply rails. In addition, it has 42 V DIACs from the external inputs to the rails, as shown in Figure 48. 500 400 300 200 100 0 0 4 8 12 16 20 VSY (V) 24 28 Figure 51. Comparator Supply Current Rev. A | Page 16 of 20 32 36 08803-051 –40 08803-100 –3 –50 ADA4092-4 OUTLINE DIMENSIONS 5.10 5.00 4.90 14 8 4.50 4.40 4.30 6.40 BSC 1 7 PIN 1 0.65 BSC 0.15 0.05 COPLANARITY 0.10 1.20 MAX 0.30 0.19 0.20 0.09 SEATING PLANE 8° 0° 0.75 0.60 0.45 COMPLIANT TO JEDEC STANDARDS MO-153-AB-1 061908-A 1.05 1.00 0.80 Figure 52. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters ORDERING GUIDE Model 1 ADA4092-4ARUZ ADA4092-4ARUZ-RL 1 Temperature Range −40°C to +125°C −40°C to +125°C Package Description 14-Lead Thin Shrink Small Outline Package [TSSOP] 14-Lead Thin Shrink Small Outline Package [TSSOP] Z = RoHS Compliant Part. Rev. A | Page 17 of 20 Package Option RU-14 RU-14 ADA4092-4 NOTES Rev. A | Page 18 of 20 ADA4092-4 NOTES Rev. A | Page 19 of 20 ADA4092-4 NOTES ©2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D08803-0-5/10(A) Rev. A | Page 20 of 20