AD8646

24 MHz Rail-to-Rail Amplifiers with Shutdown Option AD8646/AD8647/AD8648 FEATURES Offset voltage: 2.5 mV maximum Single-supply operation: 2.7 V to 5.5 V Low noise: 8 nV/√Hz Wide bandwidth: 24 MHz Slew rate: 11 V/μs Short-circuit output current: 120 mA No phase reversal Low input bias current: 1 pA Low supply current per amplifier: 2 mA maximum Unity gain stable PIN CONFIGURATIONS OUTA 1 –INA 2 +INA 3 8 V+ OUTB 06527-001 06527-003 06527-002 AD8646 7 TOP VIEW 6 –INB (Not to Scale) V– 4 5 +INB Figure 1. 8-Lead SOIC and MSOP OUTA 1 –INA 2 +INA 3 V– 4 SDA 5 10 V+ AD8647 TOP VIEW (Not to Scale) 9 8 7 6 OUTB –INB +INB SDB APPLICATIONS Battery-powered instruments Multipole filters ADC front ends Sensors Barcode scanners ASIC input or output amplifiers Audio amplifiers Photodiode amplifiers Datapath/mux/switch control Figure 2. 10-Lead MSOP OUTA 1 –INA 2 +INA 3 V+ 4 +INB 5 –INB 6 OUTB 7 14 13 OUTD –IND +IND V– +INC –INC OUTC AD8648 TOP VIEW (Not to Scale) 12 11 10 9 8 Figure 3. 14-Lead SOIC and TSSOP GENERAL DESCRIPTION The AD8646 and the AD8647 are the dual, and the AD8648 is the quad, rail-to-rail, input and output, single-supply amplifiers featuring low offset voltage, wide signal bandwidth, low input voltage, and low current noise. The AD8647 also has a low power shutdown function. The combination of 24 MHz bandwidth, low offset, low noise, and very low input bias current makes these amplifiers useful in a wide variety of applications. Filters, integrators, photodiode amplifiers, and high impedance sensors all benefit from the combination of performance features. AC applications benefit from the wide bandwidth and low distortion. TheAD8646/ AD8647/AD8648 offer high output drive capability, which is excellent for audio line drivers and other low impedance applications. Applications include portable and low powered instrumentation, audio amplification for portable devices, portable phone headsets, barcode scanners, and multipole filters. 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 single-supply systems. Rev. B 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 ©2006–2007 Analog Devices, Inc. All rights reserved. AD8646/AD8647/AD8648 TABLE OF CONTENTS Features .............................................................................................. 1 Applications....................................................................................... 1 Pin Configurations ........................................................................... 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Absolute Maximum Ratings............................................................ 6 Thermal Resistance ...................................................................... 6 ESD Caution...................................................................................6 Typical Performance Characteristics ..............................................7 Theory of Operation ...................................................................... 15 Power-Down Operation ............................................................ 15 Multiplexing Operation............................................................. 15 Outline Dimensions ....................................................................... 16 Ordering Guide .......................................................................... 18 REVISION HISTORY Revision History: AD8646/AD8647/AD8648 10/07—Revision B: Initial Combined Version Revision History: AD8646 10/07—Rev. 0 to Rev. B Combined with AD8648....................................................Universal Added AD8647 ...................................................................Universal Deleted Figure 4 and Figure 7......................................................... 7 Deleted Figure 33............................................................................ 11 Deleted Figure 7.................................................................................6 Deleted Figure 11...............................................................................7 Deleted Figure 16 and Figure 17 .....................................................8 Deleted Figure 24...............................................................................9 Deleted Figure 27, Figure 28, Figure 31, and Figure 32 ............ 10 6/07—Rev. 0 to Rev. A Changes to General Description .....................................................1 Updated Outline Dimensions....................................................... 12 Changes to Ordering Guide .......................................................... 12 8/07—Revision 0: Initial Version Revision History: AD8648 10/07—Rev. A to Rev. B Combined with AD8646....................................................Universal Added AD8647 ...................................................................Universal 1/06—Revision 0: Initial Version Rev. B | Page 2 of 20 AD8646/AD8647/AD8648 SPECIFICATIONS VSY = 5 V, VCM = VSY/2, TA = +25oC, unless otherwise noted. Table 1. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Symbol VOS ΔVOS/ΔT IB Conditions VCM = 0 V to 5V −40°C < TA < +125°C −40°C < TA < +125°C −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 Large Signal Voltage Gain Input Capacitance Differential Common Mode OUTPUT CHARACTERISTICS Output Voltage High VCM CMRR AVO CDIFF CCM VOH IOUT = 1 mA −40°C < TA < +125°C IOUT = 10 mA −40°C < TA < +125°C IOUT = 1 mA −40°C < TA < +125°C IOUT = 10 mA −40°C < TA < +125°C Short circuit At 1 MHz, AV = 1 VSY = 2.7 V to 5.5 V −40°C < TA < +125°C Shutdown of both amplifiers (AD8647 only) −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C (shutdown active) RL = 2 kΩ +2.0 +0.8 1 1 11 24 74 0.5 1 1 4.98 4.90 4.85 4.70 VCM = 0 V to 5 V RL = 2 kΩ, VO = 0.5 V to 4.5 V 0 67 104 84 116 2.5 6.7 4.99 4.92 8.4 78 ±120 5 63 80 1.5 10 1 20 40 145 200 0.1 Min Typ 0.6 1.8 0.3 Max 2.5 3.2 7.5 1 50 550 0.5 50 250 5 Unit mV mV μV/°C pA pA pA pA pA pA V dB dB pF pF V V V V mV mV mV mV mA Ω dB mA mA nA μA V V μA nA V/μs MHz Degrees μs μs μs Output Voltage Low VOL Output Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier Supply Current Shutdown Mode (AD8647) SHUTDOWN INPUTS (AD8647) Logic High Voltage (Enabled) Logic Low Voltage (Power-Down) Logic Input Current (Per Pin) Output Pin Leakage Current DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin Settling Time Amplifier Turn-On Time (AD8647) Amplifier Turn-Off Time (AD8647) Isc ZOUT PSRR ISY ISD 2.0 2.5 VINH VINL IIN SR GBP Øm ts ton toff To 0.1% 25°C, AV = 1, RL = 1 kΩ (see Figure 44) 25°C, AV = 1, RL = 1 kΩ (see Figure 45) Rev. B | Page 3 of 20 AD8646/AD8647/AD8648 Parameter NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Channel Separation Total Harmonic Distortion Plus Noise Symbol en p-p en CS THD + N Conditions 0.1 Hz to 10 Hz f = 1 kHz f = 10 kHz f = 10 kHz f = 100 kHz V p-p = 0.1 V, RL = 600 Ω, f = 25 kHz, TA = 25°C AV = +1 AV = −10 Min Typ 2.3 8 6 −115 −110 0.010 0.021 Max Unit μV nV/√Hz nV/√Hz dB dB % % Rev. B | Page 4 of 20 AD8646/AD8647/AD8648 VSY = 2.7 V, VCM = VSY/2, TA = +25oC, unless otherwise noted. Table 2. Parameter INPUT CHARACTERISTICS Offset Voltage Offset Voltage Drift Input Bias Current Symbol VOS ΔVOS/ΔT IB Conditions VCM = 0 V to 2.7 V −40°C < TA < +125°C −40°C < TA < +125°C −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 Large Signal Voltage Gain Input Capacitance Differential Common Mode OUTPUT CHARACTERISTICS Output Voltage High Output Voltage Low Output Current Closed-Loop Output Impedance POWER SUPPLY Power Supply Rejection Ratio Supply Current per Amplifier Supply Current Shutdown Mode (AD8647) SHUTDOWN INPUTS (AD8647) Logic High Voltage (Enabled) Logic Low Voltage (Power-Down) Logic Input Current (Per Pin) Output Pin Leakage Current DYNAMIC PERFORMANCE Slew Rate Gain Bandwidth Product Phase Margin Settling Time Amplifier Turn-On Time (AD8647) Amplifier Turn-Off Time (AD8647) NOISE PERFORMANCE Peak-to-Peak Noise Voltage Noise Density Channel Separation VCM CMRR AVO CDIFF CCM VOH VOL IOUT ZOUT PSRR ISY ISD IOUT = 1 mA −40°C < TA < +125°C IOUT = 1 mA −40°C < TA < +125°C Short circuit At 1 MHz, AV = 1 VSY = 2.7 V to 5.5 V −40°C < TA < +125°C Shutdown of both amplifiers (AD8647 only) −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C −40°C < TA < +125°C (shutdown active) RL = 2 kΩ +2.0 +0.8 1 1 11 24 53 0.3 1.2 1 2.3 8 6 −115 −110 2.65 2.60 VCM = 0 V to 2.7 V RL = 2 kΩ, VO = 0.5 V to 2.2 V 0 62 95 79 102 2.5 7.8 2.68 11 ±63 5 63 80 1.6 10 1 25 30 0.1 Min Typ 0.6 1.8 0.2 Max 2.5 3.2 7.0 1 50 550 0.5 50 250 2.7 Unit mV mV μV/°C pA pA pA pA pA pA V dB dB pF pF V V mV mV mA Ω dB mA mA nA μA V V μA nA V/μs MHz Degrees μs μs μs μV nV/√Hz nV/√Hz dB dB 2.0 2.5 VINH VINL VIN SR GBP Øm ts ton toff en p-p en CS To 0.1% 25°C, AV = 1, RL = 1 kΩ (see Figure 41) 25°C, AV = 1, RL = 1 kΩ (see Figure 42) 0.1 Hz to 10 Hz f = 1 kHz f = 10 kHz f = 10 kHz f = 100 kHz Rev. B | Page 5 of 20 AD8646/AD8647/AD8648 ABSOLUTE MAXIMUM RATINGS Table 3. Parameter Supply Voltage Input Voltage Differential Input Voltage Output Short Circuit to GND Storage Temperature Range Operating Temperature Range Lead Temperature (Soldering 60 sec) Junction Temperature Rating 6V GND to VSY ±3 V Indefinite −65°C to +150°C −40°C to +125°C 300°C 150°C THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, a device soldered in a circuit board for surface-mount packages. Table 4. Thermal Resistance Package Type 8-Lead SOIC_N 8-Lead MSOP 10-Lead MSOP 14-Lead SOIC_N 14-Lead TSSOP θJA 125 210 200 120 180 θJC 43 45 44 36 35 Unit °C/W °C/W °C/W °C/W °C/W 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. ESD CAUTION Rev. B | Page 6 of 20 AD8646/AD8647/AD8648 TYPICAL PERFORMANCE CHARACTERISTICS 300 250 NUMBER OF AMPLIFIERS VSY = 2.7V VCM = 1.35V TA = 25°C 2244 AMPLIFIERS NUMBER OF AMPLIFIERS 200 180 160 140 120 100 80 60 40 20 06527-004 VSY = 5V VCM = 2.5V TA = 25°C 2244 AMPLIFIERS 200 150 100 50 –1.5 –1.0 –0.5 0 0.5 1.0 1.5 2.0 –1.5 –1.0 –0.5 0 0.5 1.0 1.5 2.0 VOS (mV) VOS (mV) Figure 4. Input Offset Voltage Distribution Figure 7. Input Offset Voltage Distribution 35 30 NUMBER OF AMPLIFIERS VSY = 2.7V –40°C < TA < +125°C 35 30 NUMBER OF AMPLIFIERS VSY = 5V –40°C < TA < +125°C 25 20 15 10 5 0 0 1 2 3 4 5 6 7 TCVOS (µV/°C) 25 20 15 10 5 0 0 1 2 3 4 5 6 7 8 TCVOS (µV/°C) 06527-005 Figure 5. VOS Drift (TCVOS) Distribution Figure 8. VOS Drift (TCVOS) Distribution 2500 2000 INPUT OFFSET VOLTAGE (µV) VSY = 2.7V TA = 25°C INPUT OFFSET VOLTAGE (µV) 2500 2000 1500 1000 500 0 –500 –1000 –1500 –2000 VSY = 5V TA = 25°C 1500 1000 500 0 –500 –1000 –1500 –2000 0 0.5 1.0 1.5 2.0 2.5 3.0 06527-006 –2500 0 INPUT COMMON-MODE VOLTAGE (V) 1 2 3 4 INPUT COMMON-MODE VOLTAGE (V) 5 Figure 6. Input Offset Voltage vs. Input Common-Mode Voltage Figure 9. Input Offset Voltage vs. Input Common-Mode Voltage Rev. B | Page 7 of 20 06527-009 –2500 06527-008 06527-007 0 –2.0 0 –2.0 AD8646/AD8647/AD8648 10000 OUTPUT SATURATION VOLTAGE (mV) OUTPUT SATURATION VOLTAGE (mV) VSY = 2.7V TA = 25°C VSY – VOH 10000 VSY = 5V TA = 25°C 1000 1000 100 100 10 VOL 1 10 VSY – VOH 1 VOL 0.01 0.1 1 10 100 1000 06527-013 0.01 0.1 1 10 100 LOAD CURRENT (mA) 06527-010 0.1 0.001 0.1 0.001 LOAD CURRENT (mA) Figure 10. Output Saturation Voltage vs. Load Current Figure 13. Output Saturation Voltage vs. Load Current 25 OUTPUT SATURATION VOLTAGE (mV) OUTPUT SATURATION VOLTAGE (mV) VSY = 2.7V IL = 1mA 120 VSY = 5V VSY – VOH = 10mA 20 VSY – VOH 15 100 80 VOL = 10mA 60 10 VOL 40 5 20 VSY – VOH = 1mA VOL = 1mA –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) 06527-014 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) Figure 11. Output Saturation Voltage vs. Temperature 06527-011 0 –40 0 –40 Figure 14. Output Saturation Voltage vs. Temperature 300 VSY = 2.7V TA = 125°C INPUT BIAS CURRENT (pA) 300 VSY = 5V TA = 125°C 250 INPUT BIAS CURRENT (pA) 250 200 200 150 150 100 100 50 50 06527-012 0.75 1.00 1.25 1.50 1.75 2.00 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 COMMON-MODE VOLTAGE (V) COMMON-MODE VOLTAGE (V) Figure 12. Input Bias Current vs. Common-Mode Voltage Figure 15. Input Bias Current vs. Common-Mode Voltage Rev. B | Page 8 of 20 06527-015 0 0.50 0 0.5 AD8646/AD8647/AD8648 80 OPEN-LOOP PHASE SHIFT (Degrees) 06527-021 06527-020 06527-019 OPEN-LOOP PHASE SHIFT (Degrees) 60 VSY = 2 .7V RL = 1kΩ CL = 10pF 0 80 45 60 OPEN-LOOP GAIN (dB) VSY = 5V RL = 1kΩ CL = 10pF PHASE 0 45 OPEN-LOOP GAIN (dB) 40 90 40 90 20 ФM = 5 2° 135 20 ФM = 74° 135 GAIN 0 180 0 180 –20 225 –20 225 100k 1M FREQUENCY (Hz) 10M 06527-016 –40 10k 270 100M –40 10k 100k 1M FREQUENCY (Hz) 10M 270 100M Figure 16. Open-Loop Gain and Phase vs. Frequency Figure 19. Open-Loop Gain and Phase vs. Frequency 60 AV = 100 VSY = 2.7V TA = 25°C 60 AV = 100 VSY = 5V TA = 25°C 40 40 CLOSED-LOOP GAIN (dB) 20 AV = 10 CLOSED-LOOP GAIN (dB) 20 AV = 10 0 AV = 1 0 AV = 1 –20 –20 –40 –40 10k 100k 1M 10M 100M 06527-017 –60 1k –60 1k 10k 100k 1M 10M 100M FREQUENCY (Hz) FREQUENCY (Hz) Figure 17. Closed-Loop Gain vs. Frequency Figure 20. Closed-Loop Gain vs. Frequency 250 VSY = 2.7V TA = 25°C 120 VSY = 5V TA = 25°C 200 AV = 1 100 AV = 1 80 ZOUT (Ω) ZOUT (Ω) 150 60 AV = 100 40 AV = 10 100 AV = 100 50 AV = 10 20 06527-018 0 1 10 100 1k 10k 100k 1M FREQUENCY (kHz) 0 1 10 100 1k 10k 100k 1M FREQUENCY (kHz) Figure 18. ZOUT vs. Frequency Figure 21. ZOUT vs. Frequency Rev. B | Page 9 of 20 AD8646/AD8647/AD8648 100 VSY = 2.7V TA = 25°C 100 VSY = 5V TA = 25°C 80 80 CMRR (dB) 40 CMRR (dB) 60 60 40 20 20 06527-022 10k 100k 1M 10M 100M 10k 100k 1M 10M 100M FREQUENCY (Hz) FREQUENCY (Hz) Figure 22. CMRR vs. Frequency Figure 25. CMRR vs. Frequency 100 PSRR+ 80 VSY = 2 .7V TA = 25°C 100 PSRR+ VSY = 5V TA = 25°C 80 PSRR– PSRR (dB) 40 PSRR (dB) 60 PSRR– 60 40 20 20 10k 100k FREQUENCY (Hz) 1M 10M 06527-023 10k 100k FREQUENCY (Hz) 1M 10M Figure 23. PSRR vs. Frequency Figure 26. PSRR vs. Frequency 60 VSY = ±1.35V TA = 25°C –OS 70 60 50 OVERSHOOT (%) 50 +OS VSY = 5 V RL = 10kΩ TA = 25°C OVERSHOOT (%) 40 40 OS+ 30 20 OS– 30 20 10 10 0 10 06527-024 0 1 10 CLOAD (pF) 100 1000 100 CLOAD (pF) 1000 Figure 24. Overshoot vs. Load Capacitance Figure 27. Overshoot vs. Load Capacitance Rev. B | Page 10 of 20 06527-027 06527-026 0 1k 0 1k 06527-025 0 1k 0 1k AD8646/AD8647/AD8648 VSY = 2.7V, VCM = 1.35V, VIN = 100mV p-p, TA = 25°C, RL = 10kΩ, CL = 100pF VSY = 5V, VCM = 2.5V, VIN = 100mV p-p, TA = 25°C, RL = 10kΩ, CL = 100pF (50mV/DIV) 06527-028 (50mV/DIV) (200ns/DIV) (200ns/DIV) Figure 28. Small-Signal Transient Response Figure 31. Small-Signal Transient Response VSY = 2.7V, VIN = 2V p-p, TA = 25°C, RL = 10kΩ, CL = 100pF VSY = 5V, VIN = 4V p-p, TA = 25°C, RL = 10kΩ, CL = 100pF (2V/DIV) 06527-029 (2V/DIV) (200ns/DIV) (200ns/DIV) Figure 29. Large-Signal Transient Response Figure 32. Large-Signal Transient Response 0.08 VSY = ±2.5V RL = 600Ω 0.07 AV = 1 TA = 25°C 0.06 0.05 0.04 0.03 0.02 0.01 0 10 0.08 0.07 0.06 0.05 0.04 0.03 0.02 0.01 VSY = ±2.5V RL = 600Ω AV = –10 TA = 25°C THD + N (%) THD + N (%) 06527-030 100 1k FREQUENCY (Hz) 10k 100k 100 1k FREQUENCY (Hz) 10k 100k Figure 30. THD + Noise vs. Frequency Figure 33. THD + Noise vs. Frequency Rev. B | Page 11 of 20 06527-033 0 10 06527-032 06527-031 AD8646/AD8647/AD8648 VSY = 2.7V TO 5V TA = 25°C 1 0.1 VOLTAGE (1µV/DIV) THD + N (%) 0.01 0.001 06527037 VSY = 5V AV = 1 BW = 30kHz RL = 100kΩ f = 1kHz 0.01 0.1 1 06527-034 TIME (1s/DIV) 0.0001 0.001 OUTPUT AMPLITUDE (V rms) Figure 34. 0.1 Hz to 10 Hz Voltage Noise Figure 37. THD + Noise vs. Output Amplitude 1000 VSY = 2.7V TO 5V TA = 25°C 1000 VSY = 5V VOLTAGE NOISE DENSITY (nV/√Hz) 100 INPUT BIAS CURRENT (pA) 100 10 10 1 100 FREQUENCY (Hz) 1k 10k 06527-035 45 65 80 105 125 TEMPERATURE (°C) Figure 35. Voltage Noise Density vs. Frequency Figure 38. Input Bias Current vs. Temperature 2.5 TA = 25°C 5.0 4.5 SUPPLY CURRENT PER AMPLIFIER (mA) 2.0 4.0 OUTPUT SWING (V p-p) VSY = 5V VIN = 4.9V AV = 1 RL = 10kΩ TA = 25°C 3.5 3.0 2.5 2.0 1.5 1.0 0.5 1.5 1.0 0.5 06527-039 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 1k FREQUENCY (kHz) 10k SUPPLY VOLTAGE (V) Figure 36. Supply Current per Amplifier vs. Supply Voltage Figure 39. Maximum Output Swing vs. Frequency Rev. B | Page 12 of 20 06527-036 0 0 100 06527-038 1 10 0.1 25 AD8646/AD8647/AD8648 4.0 0 VOUT = VSY/2 SUPPLY CURRENT PER AMPLIFIER (mA) 3.5 –20 CHANNEL SEPARATION (dB) VSY = 5V RL = 2kΩ AV = –100 TA = 25°C CS (dB) = 20 log (VOUT/100 = VIN) V+ 3 VIN + – 0 2 V+ V– V– U1 R3 2kΩ 0 R1 20Ω V– U2 5 V– V+ V+ R2 6 200Ω 7 0 0 3.0 2.5 2.0 1.5 1.0 0.5 0 –40 VSY = 2.7V VSY = 5V –40 –60 –80 VIN = 2V p-p VIN = 0.5V p-p 10k FREQUENCY (Hz) 100k 06527-042 –100 –20 0 20 40 60 80 100 120 TEMPERATURE (°C) Figure 40. Supply Current per Amplifier vs. Temperature 06527-040 –120 1k Figure 43. Channel Separation SHUTDOWN PIN VSY = 2.7V RL = 1kΩ AV = 1 TA = 25°C VSY = 5V RL = 1kΩ AV = 1 TA = 25°C VOLTAGE (1V/DIV) SHUTDOWN PIN VOLTAGE (1V/DIV) AMPLIFIER OUTPUT AMPLIFIER OUTPUT 06527-043 06527-045 TIME (200ns/DIV) TIME (200ns/DIV) Figure 41. Turn-On Time Figure 44. Turn-On Time VSY = 2.7V RL = 1kΩ AV = 1 TA = 25°C VSY = 5V RL = 1kΩ AV = 1 TA = 25°C VOLTAGE (1V/DIV) VOLTAGE (1V/DIV) SHUTDOWN PIN SHUTDOWN PIN AMPLIFIER OUTPUT 06527-046 AMPLIFIER OUTPUT TIME (200ns/DIV) TIME (200ns/DIV) Figure 42. Turn-Off Time Figure 45. Turn-Off Time Rev. B | Page 13 of 20 06527-044 AD8646/AD8647/AD8648 100 VSY = 2.7V 100 VSY = 5V 10 10 ISY (nA) 1 ISY (nA) 06527-048 1 0.1 0.1 –25 –10 5 20 35 50 65 80 95 110 125 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) Figure 46. Supply Current with Op-Amp Shutdown vs. Temperature Figure 47. Supply Current with Op-Amp Shutdown vs. Temperature Rev. B | Page 14 of 20 06527-047 0.01 –40 0.01 –40 AD8646/AD8647/AD8648 THEORY OF OPERATION POWER-DOWN OPERATION The shutdown function of the AD8647 is referenced to the negative supply voltage of the operational amplifier. A logic level high (> 2.0 V) enables the device, while a logic level low (< 0.8 V) disables the device and places the output in a high impedance condition. Several outputs can be wire-OR’ed, thus eliminating a multiplexer. The logic input is a high impedance CMOS input. If dual or split supplies are used, the logic signals must be properly referred to the negative supply voltage. 8 7 5kHz 5V 1/2 AD8647 9 6 1/2 AD8647 2 3 13kHz 4 10 1 5 MULTIPLEXING OPERATION Because each op amp has a separate logic input enable pin, the outputs can be connected together if it can be guaranteed that only one op amp is active at any time. By connecting the op amps as shown in Figure 48, a multiplexer can be eliminated. With the reasonably short turn-on and turn-off times, low frequency signal paths can be smoothly selected. The turn-off time is slightly faster than the turn-on time so, even when using sections from two different packages, the overlap is less than 300 nanoseconds. 1 2kHz 2 06527-049 Figure 48. AD8647 Output Switching 2V 1V 0V 5V 0V 06527-050 TIME (200µs/DIV) Figure 49. Switching Waveforms Rev. B | Page 15 of 20 AD8646/AD8647/AD8648 OUTLINE DIMENSIONS 5.00 (0.1968) 4.80 (0.1890) 4.00 (0.1574) 3.80 (0.1497) 8 1 5 4 6.20 (0.2441) 5.80 (0.2284) 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0040) COPLANARITY 0.10 SEATING PLANE 1.75 (0.0688) 1.35 (0.0532) 0.50 (0.0196) 0.25 (0.0099) 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 45° 0.51 (0.0201) 0.31 (0.0122) 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] Narrow Body (R-8) Dimensions shown in millimeters and (inches) 3.20 3.00 2.80 3.20 3.00 2.80 8 5 1 5.15 4.90 4.65 4 PIN 1 0.65 BSC 0.95 0.85 0.75 0.15 0.00 0.38 0.22 SEATING PLANE 1.10 MAX 8° 0° 0.80 0.60 0.40 0.23 0.08 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 51. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters Rev. B | Page 16 of 20 012407-A AD8646/AD8647/AD8648 3.10 3.00 2.90 3.10 3.00 2.90 PIN 1 0.50 BSC 0.95 0.85 0.75 0.15 0.05 0.33 0.17 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-BA 1.10 MAX 8° 0° 0.80 0.60 0.40 10 6 1 5 5.15 4.90 4.65 SEATING PLANE 0.23 0.08 Figure 52. 10 Lead Mini Small Outline Package [MSOP] (RM-10) Dimensions shown in millimeters 5.10 5.00 4.90 14 8 4.50 4.40 4.30 1 7 6.40 BSC PIN 1 1.05 1.00 0.80 0.65 BSC 1.20 MAX 0.15 0.05 0.30 0.19 0.20 0.09 SEATING COPLANARITY PLANE 0.10 8° 0° 0.75 0.60 0.45 COMPLIANT TO JEDEC STANDARDS MO-153-AB-1 Figure 53. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters Rev. B | Page 17 of 20 AD8646/AD8647/AD8648 8.75 (0.3445) 8.55 (0.3366) 14 1 8 7 4.00 (0.1575) 3.80 (0.1496) 6.20 (0.2441) 5.80 (0.2283) 1.27 (0.0500) BSC 0.25 (0.0098) 0.10 (0.0039) COPLANARITY 0.10 0.51 (0.0201) 0.31 (0.0122) 1.75 (0.0689) 1.35 (0.0531) SEATING PLANE 0.50 (0.0197) 0.25 (0.0098) 8° 0° 0.25 (0.0098) 0.17 (0.0067) 1.27 (0.0500) 0.40 (0.0157) 45° 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 54. 14-Lead Standard Small Outline Package [SOIC_N] Narrow Body (R-14) Dimensions shown in millimeters and (inches) ORDERING GUIDE Model AD8646ARZ 1 AD8646ARZ-REEL1 AD8646ARZ-REEL71 AD8646ARMZ-R21 AD8646ARMZ-REEL1 AD8647ARMZ-R21 AD8647ARMZ-REEL1 AD8648ARZ1 AD8648ARZ-REEL1 AD8648ARZ-REEL71 AD8648ARUZ1 AD8648ARUZ-REEL1 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 Package Description 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead SOIC_N 8-Lead MSOP 8-Lead MSOP 10-Lead MSOP 10-Lead MSOP 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead SOIC_N 14-Lead TSSOP 14-Lead TSSOP Package Option R-8 R-8 R-8 RM-8 RM-8 RM-10 RM-10 R-14 R-14 R-14 RU-14 RU-14 060606-A Branding A1V A1V A1W A1W Z = RoHS Compliant Part. Rev. B | Page 18 of 20 AD8646/AD8647/AD8648 NOTES Rev. B | Page 19 of 20 AD8646/AD8647/AD8648 NOTES ©2006–2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D06527-0-10/07(B) Rev. B | Page 20 of 20