CMOS Rail-to-Rail General-Purpose Amplifiers AD8541/AD8542/AD8544 Single-supply operation: 2.7 V to 5.5 V Low supply current: 45 μA/amplifier Wide bandwidth: 1 MHz No phase reversal Low input currents: 4 pA Unity gain stable Rail-to-rail input and output Qualified for automotive applications PIN CONFIGURATIONS OUT A 1 AD8541 5 V+ V– 2 +IN A 3 4 –IN A 00935-001 FEATURES Figure 1. 5-Lead SC70 and 5-Lead SOT-23 (KS and RJ Suffixes) APPLICATIONS 8 NC 2 7 V+ +IN A 3 6 OUT A 4 5 NC NC 1 –IN A V– AD8541 00935-002 ASIC input or output amplifiers Sensor interfaces Piezoelectric transducer amplifiers Medical instrumentation Mobile communications Audio outputs Portable systems NC = NO CONNECT Figure 2. 8-Lead SOIC (R Suffix) Very low input bias currents enable the AD8541/AD8542/AD8544 to be used for integrators, photodiode amplifiers, piezoelectric sensors, and other applications with high source impedance. The supply current is only 45 μA per amplifier, ideal for battery operation. Rail-to-rail inputs and outputs are useful to designers buffering ASICs in single-supply systems. The AD8541/AD8542/AD8544 are optimized to maintain high gains at lower supply voltages, making them useful for active filters and gain stages. The AD8541/AD8542/AD8544 are specified over the extended industrial temperature range (–40°C to +125°C). The AD8541 is available in 5-lead SOT-23, 5-lead SC70, and 8-lead SOIC packages. The AD8542 is available in 8-lead SOIC, 8-lead MSOP, and 8-lead TSSOP surface-mount packages. The AD8544 is available in 14-lead narrow SOIC and 14-lead TSSOP surfacemount packages. All MSOP, SC70, and SOT versions are available in tape and reel only. See the Ordering Guide for automotive models. OUT A 1 –IN A AD8542 8 V+ 2 7 OUT B +IN A 3 6 –IN B V– 4 5 +IN B Figure 3. 8-Lead SOIC, 8-Lead MSOP, and 8-Lead TSSOP (R, RM, and RU Suffixes) OUT A 1 14 OUT D –IN A 2 13 –IN D +IN A 3 12 +IN D AD8544 11 V– V+ 4 +IN B 5 –IN B 6 9 –IN C OUT B 7 8 OUT C 10 +IN C 00935-004 The AD8541/AD8542/AD8544 are single, dual, and quad railto-rail input and output, single-supply amplifiers featuring very low supply current and 1 MHz bandwidth. All are guaranteed to operate from a 2.7 V single supply as well as a 5 V supply. These parts provide 1 MHz bandwidth at a low current consumption of 45 μA per amplifier. 00935-003 GENERAL DESCRIPTION Figure 4. 14-Lead SOIC and 14-Lead TSSOP (R and RU Suffixes) Rev. G 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 ©2008–2011 Analog Devices, Inc. All rights reserved. AD8541/AD8542/AD8544 TABLE OF CONTENTS Features .............................................................................................. 1 Theory of Operation ...................................................................... 13 Applications....................................................................................... 1 Notes on the AD854x Amplifiers............................................. 13 General Description ......................................................................... 1 Applications..................................................................................... 14 Pin Configurations ........................................................................... 1 Notch Filter ................................................................................. 14 Revision History ............................................................................... 2 Comparator Function ................................................................ 14 Specifications..................................................................................... 3 Photodiode Application ............................................................ 15 Electrical Characteristics............................................................. 3 Outline Dimensions ....................................................................... 16 Absolute Maximum Ratings............................................................ 6 Ordering Guide .......................................................................... 19 Thermal Resistance ...................................................................... 6 Automotive Products ................................................................. 19 ESD Caution.................................................................................. 6 Typical Performance Characteristics ............................................. 7 REVISION HISTORY 6/11—Rev. F to Rev. G Changes to Features Section and General Description Section................................................................................................ 1 Changes to Table 5............................................................................ 6 Updated Outline Dimensions ....................................................... 16 Changes to Ordering Guide .......................................................... 19 Added Automotive Products Section .......................................... 19 1/08—Rev. E to Rev. F Inserted Figure 21; Renumbered Sequentially.............................. 9 Changes to Figure 22 Caption......................................................... 9 Changes to Notch Filter Section, Figure 35, Figure 36, and Figure 37 .......................................................................................... 13 Updated Outline Dimensions ....................................................... 16 1/07—Rev. D to Rev. E Updated Format..................................................................Universal Changes to Photodiode Application Section .............................. 14 Changes to Ordering Guide .......................................................... 17 8/04—Rev. C to Rev. D Changes to Ordering Guide .............................................................5 Changes to Figure 3........................................................................ 10 Updated Outline Dimensions....................................................... 12 1/03—Rev. B to Rev. C Updated Format..................................................................Universal Changes to General Description .....................................................1 Changes to Ordering Guide .............................................................5 Changes to Outline Dimensions .................................................. 12 Rev. G | Page 2 of 20 AD8541/AD8542/AD8544 SPECIFICATIONS ELECTRICAL CHARACTERISTICS VS = 2.7 V, VCM = 1.35 V, TA = 25°C, unless otherwise noted. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions Min VOS Typ Max Unit 1 6 7 60 100 1000 30 50 500 2.7 mV mV pA pA pA pA pA pA V dB dB V/mV V/mV V/mV μV/°C fA/°C fA/°C fA/°C −40°C ≤ TA ≤ +125°C Input Bias Current IB 4 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS 0.1 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio CMRR Large Signal Voltage Gain AVO Offset Voltage Drift Bias Current Drift ΔVOS/ΔT ΔIB/ΔT Offset Current Drift ΔIOS/ΔT VCM = 0 V to 2.7 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = 0.5 V to 2.2 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C 0 40 38 100 50 2 45 500 4 100 2000 25 OUTPUT CHARACTERISTICS Output Voltage High VOH Output Voltage Low VOL Output Current IOUT ISC ZOUT Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin PSRR ISY SR tS GBP IL = 1 mA −40°C ≤ TA ≤ +125°C IL = 1 mA −40°C ≤ TA ≤ +125°C VOUT = VS − 1 V 2.575 2.550 2.65 35 100 125 15 ±20 50 f = 200 kHz, AV = 1 VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C 65 60 RL = 100 kΩ To 0.1% (1 V step) 0.4 76 38 55 75 V V mV mV mA mA Ω dB dB μA μA 0.75 5 980 63 V/μs μs kHz Degrees 40 38 <0.1 nV/√Hz nV/√Hz pA/√Hz ΦM NOISE PERFORMANCE Voltage Noise Density Current Noise Density en en in f = 1 kHz f = 10 kHz Rev. G | Page 3 of 20 AD8541/AD8542/AD8544 VS = 3.0 V, VCM = 1.5 V, TA = 25°C, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions Min VOS Typ Max Unit 1 6 7 60 100 1000 30 50 500 3 mV mV pA pA pA pA pA pA V dB dB V/mV V/mV V/mV μV/°C fA/°C fA/°C fA/°C −40°C ≤ TA ≤ +125°C Input Bias Current IB 4 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS 0.1 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio CMRR Large Signal Voltage Gain AVO Offset Voltage Drift Bias Current Drift ΔVOS/ΔT ΔIB/ΔT Offset Current Drift OUTPUT CHARACTERISTICS Output Voltage High ΔIOS/ΔT VOH Output Voltage Low VOL Output Current IOUT ISC ZOUT Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Settling Time Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Density Current Noise Density PSRR VCM = 0 V to 3 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = 0.5 V to 2.2 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C IL = 1 mA −40°C ≤ TA ≤ +125°C IL = 1 mA −40°C ≤ TA ≤ +125°C VOUT = VS − 1 V 0 40 38 100 50 2 2.875 2.850 2.955 32 100 125 18 ±25 50 f = 200 kHz, AV = 1 65 60 SR tS GBP ΦM RL = 100 kΩ To 0.01% (1 V step) 0.4 en en in f = 1 kHz f = 10 kHz Rev. G | Page 4 of 20 500 4 100 2000 25 VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C ISY 45 76 40 60 75 V V mV mV mA mA Ω dB dB μA μA 0.8 5 980 64 V/μs μs kHz Degrees 42 38 <0.1 nV/√Hz nV/√Hz pA/√Hz AD8541/AD8542/AD8544 VS = 5.0 V, VCM = 2.5 V, TA = 25°C, unless otherwise noted. Table 3. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions Min VOS Typ Max Unit 1 6 7 60 100 1000 30 50 500 5 mV mV pA pA pA pA pA pA V dB dB V/mV V/mV V/mV μV/°C fA/°C fA/°C fA/°C −40°C ≤ TA ≤ +125°C Input Bias Current IB 4 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Offset Current IOS 0.1 −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C Input Voltage Range Common-Mode Rejection Ratio CMRR Large Signal Voltage Gain AVO Offset Voltage Drift Bias Current Drift ΔVOS/ΔT ΔIB/ΔT Offset Current Drift ΔIOS/ΔT VCM = 0 V to 5 V −40°C ≤ TA ≤ +125°C RL = 100 kΩ, VO = 0.5 V to 2.2 V −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +85°C −40°C ≤ TA ≤ +125°C −40°C ≤ TA ≤ +125°C 0 40 38 20 10 2 48 40 4 100 2000 25 OUTPUT CHARACTERISTICS Output Voltage High VOH Output Voltage Low VOL Output Current IOUT ISC ZOUT Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current/Amplifier DYNAMIC PERFORMANCE Slew Rate Full Power Bandwidth Settling Time Gain Bandwidth Product Phase Margin NOISE PERFORMANCE Voltage Noise Density Current Noise Density PSRR IL = 1 mA −40°C ≤ TA ≤ +125°C IL = 1 mA −40°C ≤ TA ≤ +125°C VOUT = VS − 1 V 4.9 4.875 25 f = 200 kHz, AV = 1 65 60 SR BWP tS GBP ΦM RL = 100 kΩ, CL = 200 pF 1% distortion To 0.1% (1 V step) 0.45 en en in f = 1 kHz f = 10 kHz Rev. G | Page 5 of 20 100 125 30 ±60 45 VS = 2.5 V to 6 V −40°C ≤ TA ≤ +125°C VO = 0 V −40°C ≤ TA ≤ +125°C ISY 4.965 76 45 65 85 V V mV mV mA mA Ω dB dB μA μA 0.92 70 6 1000 67 V/μs kHz μs kHz Degrees 42 38 <0.1 nV/√Hz nV/√Hz pA/√Hz AD8541/AD8542/AD8544 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 4. Parameter Supply Voltage (VS) Input Voltage Differential Input Voltage1 Storage Temperature Range Operating Temperature Range Junction Temperature Range Lead Temperature (Soldering, 60 sec) 1 Rating 6V GND to VS ±6 V −65°C to +150°C −40°C to +125°C −65°C to +150°C 300°C For supplies less than 6 V, the differential input voltage is equal to ±VS. 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. θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages and measured using a standard 4-layer board, unless otherwise specified. Table 5. Package Type 5-Lead SC70 (KS) 5-Lead SOT-23 (RJ) 8-Lead SOIC (R) 8-Lead MSOP (RM) 8-Lead TSSOP (RU) 14-Lead SOIC (R) 14-Lead TSSOP (RU) ESD CAUTION Rev. G | Page 6 of 20 θJA 376 190 120 142 240 115 112 θJC 126 92 45 45 43 36 35 Unit °C/W °C/W °C/W °C/W °C/W °C/W °C/W AD8541/AD8542/AD8544 TYPICAL PERFORMANCE CHARACTERISTICS 180 160 VS = 2.7V AND 5V VCM = VS/2 350 140 300 INPUT BIAS CURRENT (pA) 120 100 80 60 40 250 200 150 100 –3.5 1.5 2.5 –2.5 –1.5 –0.5 0.5 INPUT OFFSET VOLTAGE (mV) 3.5 0 –40 00935-005 0 –4.5 4.5 Figure 5. Input Offset Voltage Distribution 6 0 INPUT OFFSET CURRENT (pA) 100 120 140 –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 VS = 2.7V AND 5V VCM = VS/2 5 4 3 2 1 0 –3.5 –35 –15 5 25 45 65 85 TEMPERATURE (°C) 105 145 125 –1 –55 00935-006 –4.0 –55 Figure 6. Input Offset Voltage vs. Temperature –35 –15 5 25 45 65 85 TEMPERATURE (°C) 105 125 145 00935-009 INPUT OFFSET VOLTAGE (mV) 20 40 60 80 TEMPERATURE (°C) 7 VS = 2.7V AND 5V VCM = VS/2 0.5 Figure 9. Input Offset Current vs. Temperature 9 160 VS = 2.7V AND 5V VCM = VS/2 POWER SUPPLY REJECTION (dB) 140 7 6 5 4 3 2 1 VS = 2.7V TA = 25°C 120 100 80 –PSRR 60 +PSRR 40 20 0 –20 0 –0.5 0.5 1.5 2.5 3.5 COMMON-MODE VOLTAGE (V) 4.5 5.5 –40 100 00935-007 INPUT BIAS CURRENT (pA) 0 Figure 8. Input Bias Current vs. Temperature 1.0 8 –20 00935-008 50 20 Figure 7. Input Bias Current vs. Common-Mode Voltage 1k 10k 100k FREQUENCY (Hz) 1M Figure 10. Power Supply Rejection vs. Frequency Rev. G | Page 7 of 20 10M 00935-010 NUMBER OF AMPLIFIERS 400 VS = 5V VCM = 2.5V TA = 25°C AD8541/AD8542/AD8544 60 SMALL SIGNAL OVERSHOOT (%) 100 SOURCE 10 SINK 1 0.1 0.01 0.1 1 LOAD CURRENT (mA) 10 100 +OS 40 –OS 30 20 10 0 00935-011 0.01 0.001 50 10 Figure 11. Output Voltage to Supply Rail vs. Load Current 3.0 SMALL SIGNAL OVERSHOOT (%) OUTPUT SWING (V p-p) 60 2.0 1.5 1.0 0.5 1k 10k 100k FREQUENCY (Hz) 1M 10M VS = 2.7V RL = 2kΩ TA = 25°C 50 40 +OS 30 –OS 20 10 0 00935-012 0 10k Figure 14. Small Signal Overshoot vs. Load Capacitance VS = 2.7V VIN = 2.5V p-p RL = 2kΩ TA = 25°C 2.5 100 1k CAPACITANCE (pF) 10 100 1k CAPACITANCE (pF) 10k 00935-015 1k ∆ OUTPUT VOLTAGE (mV) VS = 2.7V RL = 10kΩ TA = 25°C VS = 2.7V TA = 25°C 00935-014 10k Figure 15. Small Signal Overshoot vs. Load Capacitance Figure 12. Closed-Loop Output Voltage Swing vs. Frequency VS = 2.7V RL = ∞ TA = 25°C 50 VS = 2.7V RL = 100kΩ CL = 300pF AV = 1 TA = 25°C +OS 40 30 –OS 1.35V 20 0 10 100 1k CAPACITANCE (pF) 10k 50mV 10µs Figure 16. Small Signal Transient Response Figure 13. Small Signal Overshoot vs. Load Capacitance Rev. G | Page 8 of 20 00935-016 10 00935-013 SMALL SIGNAL OVERSHOOT (%) 60 AD8541/AD8542/AD8544 90 VS = 2.7V RL = 2kΩ AV = 1 TA = 25°C VS = 5V TA = 25°C COMMON-MODE REJECTION (dB) 80 10µs 60 50 40 30 20 10 0 –10 1k Figure 17. Large Signal Transient Response 100k FREQUENCY (Hz) 1M 10M Figure 20. Common-Mode Rejection vs. Frequency 5 VS = 2.7V RL = NO LOAD TA = 25°C VS = 5V RL = NO LOAD TA = 25°C 40 90 20 135 0 180 3 2 1 0 –1 –2 –3 00935-040 45 PHASE SHIFT (Degrees) 60 INPUT OFFSET VOLTAGE (mV) 4 80 1k 10k 100k FREQUENCY (Hz) 1M 00935-018 –4 10M –5 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 COMMON-MODE VOLTAGE (V) Figure 21. Input Offset Voltage vs. Common-Mode Voltage Figure 18. Open-Loop Gain and Phase vs. Frequency 10k 160 VS = 5V TA = 25°C 140 1k ∆ OUTPUT VOLTAGE (mV) 120 100 80 –PSRR 60 +PSRR 40 20 0 VS = 5V TA = 25°C 100 SOURCE 10 SINK 1 0.1 –20 –40 100 1k 10k 100k FREQUENCY (Hz) 1M 10M 00935-019 POWER SUPPLY REJECTION RATIO (dB) 0 Figure 19. Power Supply Rejection Ratio vs. Frequency 0.01 0.001 0.01 0.1 1 LOAD CURRENT (mA) 10 100 Figure 22. Output Voltage to Supply Rail vs. Load Current Rev. G | Page 9 of 20 00935-021 GAIN (dB) 10k 00935-020 500mV 00935-017 1.35V 70 AD8541/AD8542/AD8544 5.0 4.0 SMALL SIGNAL OVERSHOOT (%) 4.5 OUTPUT SWING (V p-p) 60 VS = 5V VIN = 4.9V p-p RL = NO LOAD TA = 25°C 3.5 3.0 2.5 2.0 1.5 1.0 VS = 5V RL = 2kΩ TA = 25°C 50 40 +OS 30 –OS 20 10 1k 10k 100k FREQUENCY (Hz) 1M 10M 0 00935-022 0 Figure 23. Closed-Loop Output Voltage Swing vs. Frequency, 5.0 10k 60 SMALL SIGNAL OVERSHOOT (%) OUTPUT SWING (V p-p) 4.0 100 1k CAPACITANCE (pF) Figure 26. Small Signal Overshoot vs. Load Capacitance VS = 5V VIN = 4.9V p-p RL = 2kΩ TA = 25°C 4.5 10 00935-025 0.5 3.5 3.0 2.5 2.0 1.5 1.0 VS = 5V RL = ∞ TA = 25°C 50 40 +OS 30 –OS 20 10 1k 10k 100k FREQUENCY (Hz) 1M 10M 0 10 Figure 24. Closed-Loop Output Voltage Swing vs. Frequency VS = 5V RL = 100kΩ CL = 300pF AV = 1 TA = 25°C VS = 5V RL = 10kΩ TA = 25°C 40 +OS 2.5V 30 –OS 10 50mV 0 10 100 1k CAPACITANCE (pF) 10k 10µs Figure 28. Small Signal Transient Response Figure 25. Small Signal Overshoot vs. Load Capacitance Rev. G | Page 10 of 20 00935-027 20 00935-024 SMALL SIGNAL OVERSHOOT (%) 10k Figure 27. Small Signal Overshoot vs. Load Capacitance 60 50 100 1k CAPACITANCE (pF) 00935-026 0 00935-023 0.5 AD8541/AD8542/AD8544 VS = 5V RL = 2kΩ AV = 1 TA = 25°C VS = 5V RL = 10kΩ AV = 1 TA = 25°C VIN VOUT 2.5V 10µs 1V Figure 29. Large Signal Transient Response 60 90 20 135 0 180 100k FREQUENCY (Hz) 1M 10M Figure 30. Open-Loop Gain and Phase vs. Frequency 50 40 30 20 10 0 0 1 2 3 4 SUPPLY VOLTAGE (V) 5 Figure 32. Supply Current per Amplifier vs. Supply Voltage Rev. G | Page 11 of 20 6 00935-031 40 PHASE SHIFT (Degrees) 45 00935-029 GAIN (dB) 60 SUPPLY CURRENT/AMPLIFIER (µA) TA = 25°C 80 10k 20µs Figure 31. No Phase Reversal VS = 5V RL = NO LOAD TA = 25°C 1k 00935-030 1V 00935-028 2.5V AD8541/AD8542/AD8544 VS = 5V MARKER SET @ 10kHz MARKER READING: 37.6nV/ Hz TA = 25°C 50 VS = 5V 15nV/DIV 45 40 VS = 2.7V 35 30 20 –55 –35 –15 5 25 45 65 85 TEMPERATURE (°C) 105 125 145 0 1000 800 VS = 2.7V AND 5V AV = 1 TA = 25°C 600 500 400 300 200 100 10k 100k 1M FREQUENCY (Hz) 10M 100M 00935-033 IMPEDANCE (Ω) 700 0 1k 10 15 FREQUENCY (kHz) Figure 35. Voltage Noise Figure 33. Supply Current per Amplifier vs. Temperature 900 5 Figure 34. Closed-Loop Output Impedance vs. Frequency Rev. G | Page 12 of 20 20 25 00935-034 25 00935-032 SUPPLY CURRENT/AMPLIFIER (µA) 55 AD8541/AD8542/AD8544 THEORY OF OPERATION NOTES ON THE AD854X AMPLIFIERS Higher Output Current The AD8541/AD8542/AD8544 amplifiers are improved performance, general-purpose operational amplifiers. Performance has been improved over previous amplifiers in several ways, including lower supply current for 1 MHz gain bandwidth, higher output current, and better performance at lower voltages. At 5 V single supply, the short-circuit current is typically 60 μA. Even 1 V from the supply rail, the AD854x amplifiers can provide a 30 mA output current, sourcing, or sinking. Lower Supply Current for 1 MHz Gain Bandwidth The AD854x series typically uses 45 μA of current per amplifier, which is much less than the 200 μA to 700 μA used in earlier generation parts with similar performance. This makes the AD854x series a good choice for upgrading portable designs for longer battery life. Alternatively, additional functions and performance can be added at the same current drain. Sourcing and sinking are strong at lower voltages, with 15 mA available at 2.7 V and 18 mA at 3.0 V. For even higher output currents, see the AD8531/AD8532/AD8534 parts for output currents to 250 mA. Information on these parts is available from your Analog Devices, Inc. representative, and data sheets are available at www.analog.com. Better Performance at Lower Voltages The AD854x family of parts was designed to provide better ac performance at 3.0 V and 2.7 V than previously available parts. Typical gain bandwidth product is close to 1 MHz at 2.7 V. Voltage gain at 2.7 V and 3.0 V is typically 500,000. Phase margin is typically over 60°C, making the part easy to use. Rev. G | Page 13 of 20 AD8541/AD8542/AD8544 APPLICATIONS The AD854x have very high open-loop gain (especially with a supply voltage below 4 V), which makes it useful for active filters of all types. For example, Figure 36 illustrates the AD8542 in the classic twin-T notch filter design. The twin-T notch is desired for simplicity, low output impedance, and minimal use of op amps. In fact, this notch filter can be designed with only one op amp if Q adjustment is not required. Simply remove U2 as illustrated in Figure 37. However, a major drawback to this circuit topology is ensuring that all the Rs and Cs closely match. The components must closely match or notch frequency offset and drift causes the circuit to no longer attenuate at the ideal notch frequency. To achieve desired performance, 1% or better component tolerances or special component screens are usually required. One method to desensitize the circuit-to-component mismatch is to increase R2 with respect to R1, which lowers Q. A lower Q increases attenuation over a wider frequency range but reduces attenuation at the peak notch frequency. Figure 38 is an example of the AD8544 in a notch filter circuit. The frequency dependent negative resistance (FDNR) notch filter has fewer critical matching requirements than the twin-T notch, where as the Q of the FDNR is directly proportional to a single resistor R1. Although matching component values is still important, it is also much easier and/or less expensive to accomplish in the FDNR circuit. For example, the twin-T notch uses three capacitors with two unique values, whereas the FDNR circuit uses only two capacitors, which may be of the same value. U3 is simply a buffer that is added to lower the output impedance of the circuit. R1 Q ADJUST 200Ω 2.5VREF 2.5VREF 1/4 AD8544 U2 6 f0 = R/2 50kΩ C 26.7nF 1 C 26.7nF U1 4 1 f= VOUT R 2.61kΩ 5 1/2 AD8542 R2 2.5kΩ 5 U2 6 R1 4 1– R1 + R2 11 R 2.61kΩ 13 12 1/4 AD8544 U4 14 NC 2.5VREF Figure 38. FDNR 60 Hz Notch Filter with Output Buffer COMPARATOR FUNCTION R1 97.5kΩ 2.5VREF Figure 36. 60 Hz Twin-T Notch Filter, Q = 10 5.0V 3 2 2C 1 R 2.61kΩ 1 2π LC1 L = R2C2 1 VIN 1/4 AD8544 U1 VIN 7 R 2 2.5VREF 2πRC R 4 3 C2 1µF 7 AD8541 U1 4 6 VOUT 2.5VREF A comparator function is a common application for a spare op amp in a quad package. Figure 39 illustrates ¼ of the AD8544 as a comparator in a standard overload detection application. Unlike many op amps, the AD854x family can double as comparators because this op amp family has a rail-to-rail differential input range, rail-to-rail output, and a great speed vs. power ratio. R2 is used to introduce hysteresis. The AD854x, when used as comparators, have 5 μs propagation delay at 5 V and 5 μs overload recovery time. R2 1MΩ R1 1kΩ C C 00935-036 R/2 Figure 37. 60 Hz Twin-T Notch Filter, Q = ∞ (Ideal) VOUT VIN 2.5VREF 2.5VDC 1/4 AD8541 00935-038 f0 = 2 2C 53.6µF 1/2 AD8542 00935-035 VIN 8 3 VOUT R 2.61kΩ 5.0V R 100kΩ 8 U3 10 C1 1µF VIN 7 R 100kΩ 1/4 AD8544 9 00935-037 NOTCH FILTER Figure 39. AD854x Comparator Application—Overload Detector Rev. G | Page 14 of 20 AD8541/AD8542/AD8544 C 100pF PHOTODIODE APPLICATION The AD854x family has very high impedance with an input bias current typically around 4 pA. This characteristic allows the AD854x op amps to be used in photodiode applications and other applications that require high input impedance. Note that the AD854x has significant voltage offset that can be removed by capacitive coupling or software calibration. • Shielding the circuit. • Cleaning the circuit board. • Putting a trace connected to the noninverting input around the inverting input. • Using separate analog and digital power supplies. V+ OR 2 7 6 3 4 D 2.5VREF 2.5VREF VOUT AD8541 00935-039 Figure 40 illustrates a photodiode or current measurement application. The feedback resistor is limited to 10 MΩ to avoid excessive output offset. In addition, a resistor is not needed on the noninverting input to cancel bias current offset because the bias current-related output offset is not significant when compared to the voltage offset contribution. For best performance, follow the standard high impedance layout techniques, which include the following: R 10MΩ Figure 40. High Input Impedance Application—Photodiode Amplifier Rev. G | Page 15 of 20 AD8541/AD8542/AD8544 OUTLINE DIMENSIONS 3.00 2.90 2.80 5 1.70 1.60 1.50 4 1 2 3.00 2.80 2.60 3 0.95 BSC 1.90 BSC 1.45 MAX 0.95 MIN 0.15 MAX 0.05 MIN 0.20 MAX 0.08 MIN 10° 5° 0° SEATING PLANE 0.50 MAX 0.35 MIN 0.60 BSC 0.55 0.45 0.35 11-01-2010-A 1.30 1.15 0.90 COMPLIANT TO JEDEC STANDARDS MO-178-AA Figure 41. 5-Lead Small Outline Transistor Package [SOT-23] (RJ-5) Dimensions shown in millimeters 5.10 5.00 4.90 14 8 4.50 4.40 4.30 6.40 BSC 1 7 PIN 1 0.65 BSC 1.20 MAX 0.15 0.05 COPLANARITY 0.10 0.30 0.19 0.20 0.09 SEATING PLANE 8° 0° COMPLIANT TO JEDEC STANDARDS MO-153-AB-1 Figure 42. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters Rev. G | Page 16 of 20 0.75 0.60 0.45 061908-A 1.05 1.00 0.80 AD8541/AD8542/AD8544 2.20 2.00 1.80 1.35 1.25 1.15 5 1 2.40 2.10 1.80 4 2 3 0.65 BSC 1.10 0.80 0.10 MAX COPLANARITY 0.10 SEATING PLANE 0.30 0.15 0.40 0.10 0.46 0.36 0.26 0.22 0.08 072809-A 1.00 0.90 0.70 COMPLIANT TO JEDEC STANDARDS MO-203-AA Figure 43. 5-Lead Thin Shrink Small Outline Transistor Package [SC70] (KS-5) Dimensions shown in millimeters 8.75 (0.3445) 8.55 (0.3366) 8 14 1 7 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122) 6.20 (0.2441) 5.80 (0.2283) 0.50 (0.0197) 0.25 (0.0098) 1.75 (0.0689) 1.35 (0.0531) SEATING PLANE 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-AB 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. Figure 44. 14-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-14) Dimensions shown in millimeters and (inches) Rev. G | Page 17 of 20 060606-A 4.00 (0.1575) 3.80 (0.1496) AD8541/AD8542/AD8544 3.20 3.00 2.80 8 1 5 8 5.15 4.90 4.65 5 4.50 4.40 4.30 4 PIN 1 IDENTIFIER 1 6.40 BSC 4 PIN 1 0.65 BSC 0.65 BSC 0.95 0.85 0.75 15° MAX 0.15 0.05 1.10 MAX 0.40 0.25 6° 0° 0.80 0.55 0.40 0.23 0.09 COPLANARITY 0.10 10-07-2009-B 0.15 0.05 COPLANARITY 0.10 1.20 MAX COMPLIANT TO JEDEC STANDARDS MO-187-AA 0.30 0.19 SEATING 0.20 PLANE 0.09 Figure 45. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters 8 1 5 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 0.75 0.60 0.45 Figure 46. 8-Lead Thin Shrink Small Outline Package [TSSOP] (RU-8) Dimensions shown in millimeters 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 8° 0° COMPLIANT TO JEDEC STANDARDS MO-153-AA 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-AA 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. Figure 47. 8-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-8) Dimensions shown in millimeters and (inches) Rev. G | Page 18 of 20 012407-A 3.20 3.00 2.80 3.10 3.00 2.90 AD8541/AD8542/AD8544 ORDERING GUIDE Model 1, 2 AD8541AKSZ-R2 AD8541AKSZ-REEL7 AD8541ARTZ-R2 AD8541ARTZ-REEL AD8541ARTZ-REEL7 AD8541ARZ AD8541ARZ-REEL AD8541ARZ-REEL7 AD8542ARZ AD8542ARZ-REEL AD8542ARZ-REEL7 AD8542ARM-REEL AD8542ARMZ AD8542ARMZ-REEL AD8542ARU-REEL AD8542ARUZ AD8542ARUZ-REEL AD8544ARZ AD8544ARZ-REEL AD8544ARZ-REEL7 AD8544ARUZ AD8544ARUZ-REEL AD8544WARZ-RL AD8544WARZ-R7 1 2 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 –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 5-Lead SC70 5-Lead SC70 5-Lead SOT-23 5-Lead SOT-23 5-Lead SOT-23 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 MSOP 8-Lead MSOP 8-Lead MSOP 8-Lead TSSOP 8-Lead TSSOP 8-Lead TSSOP 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead TSSOP 14-Lead TSSOP 14-Lead SOIC_N 14-Lead SOIC_N Package Option KS-5 KS-5 RJ-5 RJ-5 RJ-5 R-8 R-8 R-8 R-8 R-8 R-8 RM-8 RM-8 RM-8 RU-8 RU-8 RU-8 R-14 R-14 R-14 RU-14 RU-14 R-14 R-14 Branding A12 A12 A4A A4A A4A AVA AVA AVA Z = RoHS Compliant Part. W = Qualified for Automotive Applications. AUTOMOTIVE PRODUCTS The AD8544W models are available with controlled manufacturing to support the quality and reliability requirements of automotive applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to obtain the specific Automotive Reliability reports for these models. Rev. G | Page 19 of 20 AD8541/AD8542/AD8544 NOTES ©2008–2011 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D00935-0-6/11(G) Rev. G | Page 20 of 20