Precision Micropower, Low Noise CMOS, Rail-to-Rail Input/Output Operational Amplifiers AD8603/AD8607/AD8609 OUT 1 V- 2 V+ 4 -IN OUT A 1 AD8607 TOP VIEW (Not to Scale) V- 4 8 V+ 7 OUT B 6 -IN B 5 +IN B OUT A 1 -IN A 2 AD8607 8 V+ 7 OUT B The AD8603/AD8607/AD8609 are single/dual/quad micropower rail-to-rail input and output amplifiers, respectively, that feature very low offset voltage as well as low input voltage and current noise. These amplifiers use a patented trimming technique that achieves superior precision without laser trimming. The parts are fully specified to operate from 1.8 V to 5.0 V single supply or from 0.9 V to 2.5 V dual supply. The combination of low offsets, low noise, very low input bias currents, and low power consumption makes the AD8603/AD8607/AD8609 especially useful in portable and loop-powered instrumentation. The ability to swing rail to rail at both the input and output enables designers to buffer CMOS ADCs, DACs, ASICs, and other wide output swing devices in low power, single-supply systems. The AD8603 is available in a tiny 5-lead TSOT package. The AD8607 is available in 8-lead MSOP and 8-lead SOIC packages. The AD8609 is available in 14-lead TSSOP and 14-lead SOIC packages. 6 -IN B TOP VIEW V- 4 (Not to Scale) 5 +IN B 04356-003 Figure 2. 8-Lead MSOP (RM Suffix) +IN A 3 GENERAL DESCRIPTION 04356-002 Figure 1. 5-Lead TSOT (UJ Suffix) +IN A 3 Battery-powered instrumentation Multipole filters Sensors Low power ASIC input or output amplifiers 5 TOP VIEW (Not to Scale) +IN 3 -IN A 2 APPLICATIONS AD8603 04356-001 PIN CONFIGURATIONS Figure 3. 8-Lead SOIC (R Suffix) OUT A 1 14 OUT D -IN A 2 13 -IN D AD8609 12 +IN D TOP VIEW (Not to Scale) 11 V- +IN B 5 10 +IN C -IN B 6 9 -IN C OUT B 7 8 OUT C +IN A 3 V+ 4 04356-004 Low offset voltage: 50 V maximum Low input bias current: 1 pA maximum Single-supply operation: 1.8 V to 5 V Low noise: 22 nV/Hz Micropower: 50 A maximum Low distortion No phase reversal Unity gain stable Figure 4. 14-Lead TSSOP (RU Suffix) OUT A 1 14 OUT D -IN A 2 +IN A 3 V+ 4 +IN B 5 13 -IN D AD8609 12 +IN D TOP VIEW 11 V- (Not to Scale) 10 +IN C -IN B 6 9 -IN C OUT B 7 8 OUT C 04356-005 FEATURES Figure 5. 14-Lead SOIC (R Suffix) 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 (c)2003-2008 Analog Devices, Inc. All rights reserved. AD8603/AD8607/AD8609 TABLE OF CONTENTS Features .............................................................................................. 1 Applications..................................................................................... 12 Applications ....................................................................................... 1 No Phase Reversal ...................................................................... 12 General Description ......................................................................... 1 Input Overvoltage Protection ................................................... 12 Pin Configurations ........................................................................... 1 Driving Capacitive Loads .......................................................... 12 Revision History ............................................................................... 2 Proximity Sensors....................................................................... 13 Specifications..................................................................................... 3 Composite Amplifiers................................................................ 13 Electrical Characteristics ............................................................. 3 Battery-Powered Applications .................................................. 13 Absolute Maximum Ratings............................................................ 5 Photodiodes ................................................................................ 13 ESD Caution .................................................................................. 5 Outline Dimensions ....................................................................... 14 Typical Performance Characteristics ............................................. 6 Ordering Guide .......................................................................... 16 REVISION HISTORY 6/08--Rev. B to Rev. C Changes to Table 1 ............................................................................ 3 Changes to Table 2 ............................................................................ 4 Changes to Figure 15 ........................................................................ 7 Changes to Figure 33 ...................................................................... 10 Changes to Figure 45 and Figure 47 ............................................. 13 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 16 6/05--Rev. A to Rev. B Updated Figure 49 .......................................................................... 15 Changes to Ordering Guide .......................................................... 17 10/03--Rev. 0 to Rev. A Added AD8607 and AD8609 Parts .................................. Universal Changes to Specifications ................................................................ 3 Changes to Figure 35 ...................................................................... 10 Added Figure 41.............................................................................. 11 8/03--Revision 0: Initial Version Rev. C | Page 2 of 16 AD8603/AD8607/AD8609 SPECIFICATIONS ELECTRICAL CHARACTERISTICS VS = 5 V, VCM = VS/2, TA = 25C, unless otherwise noted. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions VOS Offset Voltage Drift Input Bias Current VOS/T IB VS = 3.3 V @ VCM = 0.5 V and 2.8 V -0.3 V < VCM < +5.2 V -40C < TA < +125C, -0.3 V < VCM < +5.2 V -40C < TA < +125C Min Typ Max Unit 12 40 50 300 700 4.5 1 50 500 0.5 50 250 +5.2 V V V V/C pA pA pA pA pA pA V dB dB 1 0.2 -40C < TA < +85C -40C < TA < +125C Input Offset Current IOS 0.1 -40C < TA < +85C -40C < TA < +125C Input Voltage Range Common-Mode Rejection Ratio IVR CMRR Large Signal Voltage Gain AD8603 AD8607/AD8609 Input Capacitance AVO OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low 0 V < VCM < 5 V -40C < TA < +125C RL = 10 k, 0.5 V < VO < 4.5 V -0.3 85 80 400 250 1000 450 1.9 2.5 V/mV V/mV pF pF 4.95 4.9 4.65 4.50 4.97 V V V V mV mV mV mV mA CDIFF CCM VOH VOL 4.97 16 160 Short-Circuit Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier PSRR ISY 1.8 V < VS < 5 V VO = 0 V -40C <TA < +125C DYNAMIC PERFORMANCE Slew Rate Settling Time 0.1% Gain Bandwidth Product SR tS GBP RL = 10 k G = 1, 2 V step RL = 100 k RL = 10 k RL = 10 k, RL = 100 k 0.1 23 400 316 70 0.1 Hz to 10 Hz f = 1 kHz f = 10 kHz f = 1 kHz f = 10 kHz f = 100 kHz 2.3 25 22 0.05 -115 -110 Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density Channel Separation ISC ZOUT IL = 1 mA -40C to +125C IL = 10 mA -40C to +125C IL = 1 mA -40C to +125C IL = 10 mA -40C to +125C 100 OO en p-p en in CS 70 36 f = 10 kHz, AV = 1 Rev. C | Page 3 of 16 30 50 250 330 80 100 40 50 60 dB A A V/s s kHz kHz Degrees 3.5 V nV/Hz nV/Hz pA/Hz dB dB AD8603/AD8607/AD8609 VS = 1.8 V, VCM = VS/2, TA = 25C, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Symbol Conditions VOS Offset Voltage Drift Input Bias Current VOS/T IB VS = 3.3 V @ VCM = 0.5 V and 2.8 V -0.3 V < VCM < +1.8 V -40C < TA < +85C, -0.3 V < VCM < +1.8 V -40C < TA < +125C, -0.3 V < VCM < +1.7 V -40C < TA < +125C Min Typ Max Unit 12 40 50 300 500 700 4.5 1 50 500 0.5 50 250 +1.8 V V V V V/C pA pA pA pA pA pA V dB dB 1 0.2 -40C < TA < +85C -40C < TA < +125C Input Offset Current IOS 0.1 -40C < TA < +85C -40C < TA < +125C Input Voltage Range Common-Mode Rejection Ratio IVR CMRR Large Signal Voltage Gain AD8603 AD8607/AD8609 Input Capacitance AVO OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low 0 V < VCM < 1.8 V -40C < TA < +85C RL = 10 k, 0.5 V < VO < 4.5 V -0.3 80 70 150 100 3000 2000 2.1 3.8 V/mV V/mV pF pF 1.65 1.6 1.72 V V mV mV mA CDIFF CCM VOH VOL 38 Short-Circuit Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier PSRR ISY 1.8 V < VS < 5 V VO = 0 V -40C < TA < +85C DYNAMIC PERFORMANCE Slew Rate Settling Time 0.1% Gain Bandwidth Product SR tS GBP RL = 10 k G = 1, 1 V step RL = 100 k RL = 10 k RL = 10 k, RL = 100 k 0.1 9.2 385 316 70 0.1 Hz to 10 Hz f = 1 kHz f = 10 kHz f = 1 kHz f = 10 kHz f = 100 kHz 2.3 25 22 0.05 -115 -110 Phase Margin NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Current Noise Density Channel Separation ISC ZOUT IL = 1 mA -40C to +125C IL = 1 mA -40C to +125C 98 OO en p-p en in CS 10 36 f = 10 kHz, AV = 1 Rev. C | Page 4 of 16 60 80 80 100 40 50 60 dB A A V/s s kHz kHz Degrees 3.5 V nV/Hz nV/Hz pA/Hz dB dB AD8603/AD8607/AD8609 ABSOLUTE MAXIMUM RATINGS Absolute maximum ratings apply at 25C, unless otherwise noted. Table 3. Parameter Supply Voltage Input Voltage Differential Input Voltage Output Short-Circuit Duration to GND Storage Temperature Range Lead Temperature (Soldering, 60 sec) Operating Temperature Range Junction Temperature Range Rating 6V GND to VS 6 V Indefinite -65C to +150C 300C -40C to +125C -65C to +150C Table 4. Package Characteristics Package Type 5-Lead TSOT (UJ) 8-Lead MSOP (RM) 8-Lead SOIC_N (R) 14-Lead SOIC_N (R) 14-Lead TSSOP (RU) JA1 207 210 158 120 180 JC 61 45 43 36 35 Unit C/W C/W C/W C/W C/W 1 JA is specified for the worst-case conditions, that is, JA is specified for a device soldered in a circuit board for surface-mount packages. 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. C | Page 5 of 16 AD8603/AD8607/AD8609 TYPICAL PERFORMANCE CHARACTERISTICS 300 2600 2200 VS = 5V TA = 25C VCM = 0V TO 5V 200 150 1800 100 1600 50 VOS (V) 1400 1200 1000 -150 600 400 -200 200 -250 -270 -210 -150 -90 -30 0 30 VOS (V) 90 150 210 270 -300 0.3 VS = 2.5V TA = -40C TO +125C VCM = 0V 1.2 1.5 1.8 VCM (V) (V) 2.1 2.4 2.7 3.0 3.3 VS = 2.5V 20 15 10 5 300 250 200 150 100 0.4 0.8 1.2 1.6 2.0 2.4 2.8 3.2 3.6 4.0 4.4 4.8 5.2 TCVOS (V/C) 0 04356-007 0 25 0 75 50 TEMPERATURE (C) 100 125 04356-010 50 Figure 10. Input Bias Current vs. Temperature Figure 7. Input Offset Voltage Drift Distribution 1000 OUTPUT VOLTAGE TO SUPPLY RAIL (mV) VS = 5V TA = 25C 200 150 100 50 0 -50 -100 -150 -200 -250 0.5 1.0 1.5 2.0 2.5 3.0 VCM (V) 3.5 4.0 4.5 5.0 100 10 SOURCE 1 Figure 8. Input Offset Voltage vs. Common-Mode Voltage SINK 0.1 0.01 0.001 04356-008 0 VS = 5V TA = 25C 0.01 0.1 LOAD CURRENT (mA) 1 Figure 11. Output Voltage to Supply Rail vs. Load Current Rev. C | Page 6 of 16 10 04356-011 300 250 VOS (V) 0.9 350 INPUT BIAS CURRENT (pA) 25 -300 0.6 400 30 0 0 Figure 9. Input Offset Voltage vs. Common-Mode Voltage Figure 6. Input Offset Voltage Distribution NUMBERS OF AMPLIFIERS 0 -50 -100 800 04356-006 NUMBER OF AMPLIFIERS 2000 0 VS = 3.3V TA = 25C 250 04356-009 2400 AD8603/AD8607/AD8609 350 1575 OUTPUT IMPEDANCE () 200 VOL @ 10mA LOAD 150 100 VDD - VOH @ 1mA LOAD 20 35 50 65 TEMPERATURE (C) 80 95 110 525 350 125 0 100 140 180 120 135 100 90 20 45 0 0 -45 -90 -60 -135 -20 -80 -180 -40 20 0 -225 10M -60 100 VS = 5V VIN = 4.9V p-p TA = 25C AV = 1 100 60 2.5 2.0 40 20 0 1.0 -20 0.5 -40 1 FREQUENCY (kHz) 10 100 04356-014 1.5 -60 10 100 1k FREQUENCY (Hz) 10k Figure 17. PSRR vs. Frequency Figure 14. Closed-Loop Output Voltage Swing vs. Frequency Rev. C | Page 7 of 16 100k 04356-017 PSRR (dB) 80 3.0 0.1 VS = 2.5V 120 3.5 0 0.01 100k 140 5.0 4.0 1k 10k FREQUENCY (Hz) Figure 16. CMRR vs. Frequency Figure 13. Open-Loop Gain and Phase vs. Frequency 4.5 VS = 2.5V 40 -40 1M 100k 60 -20 100k FREQUENCY (Hz) 10k FREQUENCY (Hz) 80 CMRR (dB) 40 04356-013 OPEN-LOOP GAIN (dB) 60 225 PHASE (Degree) VS = 2.5V RL = 100k CL = 20pF = 70.9 80 1k Figure 15. Output Impedance vs. Frequency 100 10k AV = 1 700 Figure 12. Output Voltage Swing vs. Temperature -100 1k AV = 10 875 04356-015 5 AV = 100 1050 175 VOL @ 1mA LOAD -10 1225 04356-016 50 0 -40 -25 OUTPUT VOLTAGE SWING (V p-p) VS = 2.5V, 0.9V 1400 VDD - VOH @ 10mA LOAD 250 04356-012 OUTPUT VOLTAGE SWING (mV) 300 1750 VS = 5V TA = 25C AD8603/AD8607/AD8609 60 VS = 5V, 1.8V VS = 5V OS- 30 20 OS+ 10 0 10 100 LOAD CAPACITANCE (pF) 1000 TIME (1s/DIV) Figure 18. Small Signal Overshoot vs. Load Capacitance 04356-021 VOLTAGE NOISE (1V/DIV) 40 04356-018 SMALL SIGNAL OVERSHOOT (%) 50 Figure 21. 0.1 Hz to 10 Hz Input Voltage Noise 60 VS = 5V RL = 10k CL = 200pF AV = 1 VS = 2.5V 55 50 VOLTAGE (50mV/DIV) SUPPLY CURRENT (A) 45 40 35 30 25 20 15 10 -10 5 20 35 50 65 TEMPERATURE (C) 80 95 110 125 TIME (4s/DIV) Figure 19. Supply Current vs. Temperature 100 Figure 22. Small Signal Transient TA = 25C 90 VS = 5V RL = 10k CL = 200pF AV = 1 80 VOLTAGE (1V/DIV) 70 60 50 40 30 20 0 0 1 2 3 SUPPLY VOLTAGE (V) 4 5 TIME (20s/DIV) Figure 23. Large Signal Transient Figure 20. Supply Current vs. Supply Voltage Rev. C | Page 8 of 16 04356-023 10 04356-020 SUPPLY CURRENT (A) 04356-022 -25 04356-019 5 0 -40 AD8603/AD8607/AD8609 0V VIN (mV) 0V 04356-024 -50mV TIME (4s/DIV)) (40s/DIV) 154 132 110 88 66 44 22 0 0 +2.5V 0V 0V -50mV 4 5 6 FREQUENCY (kHz) 7 8 9 10 VS = 1.8V TA = 25C VCM = 0V TO 1.8V 700 650 600 550 500 450 400 350 300 250 200 150 04356-025 50 0 -300 -240 -180 -120 Figure 25. Positive Overload Recovery -60 60 0 VOS (V) 120 180 240 300 04356-028 100 TIME (4s/DIV) Figure 28. VOS Distribution 300 168 VS = 2.5V VS = 1.8V TA = 25C 250 144 200 150 120 100 50 VOS (V) 96 72 0 -50 -100 48 -150 -200 24 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 FREQUENCY (kHz) 0.8 0.9 1.0 -300 0 0.3 0.6 0.9 V VCM (V) CM(V) 1.2 1.5 Figure 29. Input Offset Voltage vs. Common-Mode Voltage Figure 26. Voltage Noise Density vs. Frequency Rev. C | Page 9 of 16 1.8 04356-029 -250 0 04356-026 VOLTAGE NOISE DENSITY (nV/Hz) 3 800 750 VS = 2.5V RL = 10k AV = 100 VIN = 50mV VIN (mV) 2 Figure 27. Voltage Noise Density vs. Frequency NUMBER OF AMPLIFIERS VOUT (V) Figure 24. Negative Overload Recovery 1 04356-027 +2.5V VS = 2.5V VOLTAGE NOISE DENSITY (nV/Hz) VOUT (V) 176 VS = 2.5V RL = 10k AV = 100 VIN = 50mV AD8603/AD8607/AD8609 225 80 60 OPEN-LOOP GAIN (dB) 100 10 SOURCE SINK 1 0.1 0.01 0.001 0.01 0.1 LOAD CURRENT (mA) 10 1 90 20 45 0 0 -20 -45 -40 -90 -60 -135 -80 -180 -100 1k 100k FREQUENCY (Hz) 1M -225 10M 140 120 90 VS = 1.8V 80 VS = 1.8V 100 80 VDD - VOH @ 1mA LOAD 60 CMRR (dB) 60 50 VOL @ 1mA LOAD 40 40 20 30 0 20 -20 10 -40 0 -40 -25 -10 5 35 50 65 20 TEMPERATURE (C) 80 95 110 125 -60 100 Figure 31. Output Voltage Swing vs. Temperature 1k 10k FREQUENCY (Hz) 100k 04356-034 70 04356-031 Figure 34. CMRR vs. Frequency 60 1.8 OUTPUT VOLTAGE SWING (V p-p) VS = 1.8V TA = 25C AV = 1 40 30 20 OS- 10 1.5 1.2 VS = 1.8V VIN = 1.7V p-p TA = 25C AV = 1 0.9 0.6 0.3 0 10 100 LOAD CAPACITANCE (pF) 1000 04356-032 OS+ Figure 32. Small Signal Overshoot vs. Load Capacitance 0 0.01 0.1 1 FREQUENCY (kHz) 10 100 Figure 35. Closed-Loop Output Voltage Swing vs. Frequency Rev. C | Page 10 of 16 04356-035 OUTPUT VOLTAGE SWING (mV) 10k Figure 33. Open-Loop Gain and Phase vs. Frequency 100 SMALL SIGNAL OVERSHOOT (%) 135 40 Figure 30. Output Voltage to Supply Rail vs. Load Current 50 180 PHASE (Degrees) VS = 0.9V RL = 100k CL = 20pF = 70 04356-033 100 VS = 1.8V TA = 25C 04356-030 OUTPUT VOLTAGE TO SUPPLY RAIL (mV) 1000 AD8603/AD8607/AD8609 176 VS = 1.8V RL = 10k CL = 200pF AV = 1 VS = 0.9V TIME (4s/DIV) 132 110 88 66 44 22 0 0 1 2 3 4 5 6 FREQUENCY (kHz) 7 8 9 10 04356-039 04356-036 VOLTAGE (50mV/DIV) VOLTAGE NOISE DENSITY (nV/Hz) 154 Figure 39. Voltage Noise Density vs. Frequency Figure 36. Small Signal Transient 0 VS = 2.5V, 0.9V VS = 1.8V RL = 10k CL = 200pF AV = 1 VOLTAGE (500mV/DIV) CHANNEL SEPARATION (dB) -20 -40 -60 -80 -100 TIME (20s/DIV) Figure 37. Large Signal Transient 140 112 84 56 28 0.1 0.2 0.3 0.4 0.5 0.6 0.7 FREQUENCY (kHz) 0.8 0.9 1.0 04356-038 VOLTAGE NOISE DENSITY (nV/Hz) VS = 0.9V 0 1k 10k FREQUENCY (Hz) 100k Figure 40. Channel Separation vs. Frequency 168 0 -140 100 Figure 38. Voltage Noise Density vs. Frequency Rev. C | Page 11 of 16 1M 04356-040 04356-037 -120 AD8603/AD8607/AD8609 APPLICATIONS NO PHASE REVERSAL The AD8603/AD8607/AD8609 do not exhibit phase inversion even when the input voltage exceeds the maximum input common-mode voltage. Phase reversal can cause permanent damage to the amplifier, resulting in system lockups. The AD8603/AD8607/AD8609 can handle voltages of up to 1 V over the supply. The use of the snubber circuit is usually recommended for unity gain configurations. Higher gain configurations help improve the stability of the circuit. Figure 44 shows the same output response with the snubber in place. VS = 0.9V VIN = 100mV CL = 2nF RL = 10k VS = 2.5V VIN = 6V p-p AV = 1 RL = 10k VOLTAGE (1V/DIV) VIN 04356-042 VOUT Figure 42. Output Response to a 2 nF Capacitive Load, Without Snubber V- V+ Figure 41. No Phase Response 200mV INPUT OVERVOLTAGE PROTECTION + - VCC RS 150 CS 47pF CL 04356-043 TIME (4s/DIV) 04356-041 VEE Figure 43. Snubber Network If a voltage 1 V higher than the supplies is applied at either input, the use of a limiting series resistor is recommended. If both inputs are used, each one should be protected with a series resistor. VSY = 0.9V VIN = 100mV CL = 2nF RL = 10k RS = 150 CS = 470pF To ensure good protection, the current should be limited to a maximum of 5 mA. The value of the limiting resistor can be determined from the following equation: (VIN - VS)/(RS + 200 ) 5 mA DRIVING CAPACITIVE LOADS Although it is configured in positive unity gain (the worst case), the AD8603 shows less than 20% overshoot. Simple additional circuitry can eliminate ringing and overshoot. One technique is the snubber network, which consists of a series RC and a resistive load (see Figure 43). With the snubber in place, the AD8603/AD8607/AD8609 are capable of driving capacitive loads of 2 nF with no ringing and less than 3% overshoot. 04356-044 The AD8603/AD8607/AD8609 are capable of driving large capacitive loads without oscillating. Figure 42 shows the output of the AD8603/AD8607/AD8609 in response to a 100 mV input signal, with a 2 nF capacitive load. Figure 44. Output Response to a 2 nF Capacitive Load with Snubber Optimum values for RS and CS are determined empirically; Table 5 lists a few starting values. Table 5. Optimum Values for the Snubber Network CL (pF) 100 to ~500 1500 1600 to ~2000 Rev. C | Page 12 of 16 RS () 500 100 400 CS (pF) 680 330 100 AD8603/AD8607/AD8609 PROXIMITY SENSORS BATTERY-POWERED APPLICATIONS Proximity sensors can be capacitive or inductive and are used in a variety of applications. One of the most common applications is liquid level sensing in tanks. This is particularly popular in pharmaceutical environments where a tank must know when to stop filling or mixing a given liquid. In aerospace applications, these sensors detect the level of oxygen used to propel engines. Whether in a combustible environment or not, capacitive sensors generally use low voltage. The precision and low voltage of the AD8603/AD8607/AD8609 make the parts an excellent choice for such applications. The AD8603/AD8607/AD8609 are ideal for battery-powered applications. The parts are tested at 5 V, 3.3 V, 2.7 V, and 1.8 V and are suitable for various applications whether in single or dual supply. COMPOSITE AMPLIFIERS A composite amplifier can provide a very high gain in applications where high closed-loop dc gains are needed. The high gain achieved by the composite amplifier comes at the expense of a loss in phase margin. Placing a small capacitor, CF, in the feedback in parallel with R2 (see Figure 45) improves the phase margin. Picking CF = 50 pF yields a phase margin of about 45 for the values shown in Figure 45. CF R2 99k VEE AD8603 V- VCC U5 V- R3 1k VEE R4 04356-045 VCC VIN 99k Photodiodes have a wide range of applications from barcode scanners to precision light meters and CAT scanners. The very low noise and low input bias current of the AD8603/AD8607/ AD8609 make the parts very attractive amplifiers for I-V conversion applications. Figure 47 shows a simple photodiode circuit. The feedback capacitor helps the circuit maintain stability. The signal bandwidth can be increased at the expense of an increase in the total noise; a low-pass filter can be implemented by a simple RC network at the output to reduce the noise. The signal bandwidth can be calculated by 1/2R2C2, and the closed-loop bandwidth is the intersection point of the open-loop gain and the noise gain. The circuit shown in Figure 47 has a closed-loop bandwidth of 58 kHz and a signal bandwidth of 16 Hz. Increasing C2 to 50 pF yields a closed-loop bandwidth of 65 kHz, but only 3.2 Hz of signal bandwidth can be achieved. AD8541 V+ V+ PHOTODIODES C2 10pF Figure 45. High Gain Composite Amplifier A composite amplifier can be used to optimize dc and ac characteristics. Figure 46 shows an example using the AD8603 and the AD8541. This circuit offers many advantages. The bandwidth is increased substantially, and the input offset voltage and noise of the AD8541 become insignificant because they are divided by the high gain of the AD8603. The circuit in Figure 46 offers high bandwidth (nearly double that of the AD8603), high output current, and very low power consumption of less than 100 A. R2 VEE R1 1k VCC AD8603 R3 1k V+ V- C2 V+ VCC R4 100 AD8541 VEE C3 04356-046 VIN VEE V- AD8603 R1 1000M C1 10pF V+ VCC Figure 47. Photodiode Circuit 100k V- R2 1000M Figure 46. Low Power Composite Amplifier Rev. C | Page 13 of 16 04356-047 R1 1k In addition to their low offset voltage and low input bias, the AD8603/AD8607/AD8609 have a very low supply current of 40 A, making the parts an excellent choice for portable electronics. The TSOT package allows the AD8603 to be used on smaller board spaces. AD8603/AD8607/AD8609 OUTLINE DIMENSIONS 2.90 BSC 5 4 2.80 BSC 1.60 BSC 1 2 3 PIN 1 0.95 BSC 1.90 BSC *0.90 0.87 0.84 *1.00 MAX 0.10 MAX 0.50 0.30 0.20 0.08 8 4 0 SEATING PLANE 0.60 0.45 0.30 *COMPLIANT TO JEDEC STANDARDS MO-193-AB WITH THE EXCEPTION OF PACKAGE HEIGHT AND THICKNESS. Figure 48. 5-Lead Thin Small Outline Transistor Package [TSOT] (UJ-5) Dimensions shown in millimeters 3.20 3.00 2.80 8 3.20 3.00 2.80 1 5 5.15 4.90 4.65 4 PIN 1 0.65 BSC 0.95 0.85 0.75 1.10 MAX 0.15 0.00 0.38 0.22 COPLANARITY 0.10 0.23 0.08 8 0 SEATING PLANE COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 49. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters Rev. C | Page 14 of 16 0.80 0.60 0.40 AD8603/AD8607/AD8609 5.00 (0.1968) 4.80 (0.1890) 8 4.00 (0.1574) 3.80 (0.1497) 5 1 4 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) 6.20 (0.2441) 5.80 (0.2284) 1.75 (0.0688) 1.35 (0.0532) 0.51 (0.0201) 0.31 (0.0122) COPLANARITY 0.10 SEATING PLANE 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) 012407-A 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. Figure 50. 8-Lead Standard Small Outline Package [SOIC_N] (R-8) Dimensions shown in millimeters and (inches) 8.75 (0.3445) 8.55 (0.3366) 4.00 (0.1575) 3.80 (0.1496) 8 14 1 7 1.27 (0.0500) BSC 0.50 (0.0197) 0.25 (0.0098) 1.75 (0.0689) 1.35 (0.0531) 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10 6.20 (0.2441) 5.80 (0.2283) SEATING PLANE 0.51 (0.0201) 0.31 (0.0122) 8 0 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 060606-A 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 51. 14-Lead Standard Small Outline Package [SOIC_N] (R-14) Dimensions shown in millimeters and (inches) 5.10 5.00 4.90 14 8 4.50 4.40 4.30 6.40 BSC 1 7 PIN 1 1.05 1.00 0.80 0.65 BSC 1.20 MAX 0.15 0.05 0.30 0.19 45 0.20 0.09 SEATING COPLANARITY PLANE 0.10 8 0 COMPLIANT TO JEDEC STANDARDS MO-153-AB-1 Figure 52. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters Rev. C | Page 15 of 16 0.75 0.60 0.45 AD8603/AD8607/AD8609 ORDERING GUIDE Model AD8603AUJ-R2 AD8603AUJ-REEL AD8603AUJ-REEL7 AD8603AUJZ-R2 1 AD8603AUJZ-REEL1 AD8603AUJZ-REEL71 AD8607ARM-R2 AD8607ARM-REEL AD8607ARMZ-R21 AD8607ARMZ-REEL1 AD8607AR AD8607AR-REEL AD8607AR-REEL7 AD8607ARZ1 AD8607ARZ-REEL1 AD8607ARZ-REEL71 AD8609AR AD8609AR-REEL AD8609AR-REEL7 AD8609ARZ1 AD8609ARZ-REEL1 AD8609ARZ-REEL71 AD8609ARU AD8609ARU-REEL AD8609ARUZ1 AD8609ARUZ-REEL1 1 Temperature Range -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C -40C to +125C Package Description 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 5-Lead TSOT 8-Lead MSOP 8-Lead MSOP 8-Lead MSOP 8-Lead MSOP 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead TSSOP 14-Lead TSSOP 14-Lead TSSOP 14-Lead TSSOP Z = RoHS Compliant Part. (c)2003-2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D04356-0-6/08(C) Rev. C | Page 16 of 16 Package Option UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 UJ-5 RM-8 RM-8 RM-8 RM-8 R-8 R-8 R-8 R-8 R-8 R-8 R-14 R-14 R-14 R-14 R-14 R-14 RU-14 RU-14 RU-14 RU-14 Branding BFA BFA BFA A0X A0X A0X A00 A00 A0G A0G