ANALOG DEVICES ADA4505-2

10 μA, Rail-to-Rail I/O, Zero Input Crossover Distortion Amplifiers ADA4505-1/ADA4505-2/ADA4505-4 FEATURES PIN CONFIGURATIONS PSRR: 100 dB minimum OUT 1 5 V+ CMRR: 105 dB typical OUT A 1 8 V+ ADA4505-1 Very low supply current: 10 μA per amplifier maximum V– 2 TOP VIEW ADA4505-2 –IN A 2 7 OUT B (Not to Scale) TOP VIEW 1.8 V to 5 V single-supply or ±0.9 V to ±2.5 V dual-supply operation +IN A 3 6 –IN B +IN 3 4 –IN (Not to Scale) Rail-to-rail input and output V– 4 5 +IN B 3 mV offset voltage maximum Figure 1. 5-Lead SOT-23 (RJ-5) Figure 2. 8-Lead MSOP (RM-8) Very low input bias current: 0.5 pA typical BALL A1 INDICATOR APPLICATIONS BALL A1 CORNER Pressure and position sensors OUT V+ A1 A2 Remote security OUT B V+ OUT A Medical monitors V– NC A1 A2 A3 B1 B2 Battery-powered consumer equipment –IN B –IN A +IN –IN Hazard detectors B1 B3 C1 C2 +IN B V– +IN A GENERAL DESCRIPTION C1 C2 C3 The ADA4505-1/ADA4505-2/ADA4505-4 are single, dual, and ADA4505-1 TOP VIEW quad micropower amplifiers featuring rail-to-rail input and output (BALL SIDE DOWN) ADA4505-2 Not to Scale TOP VIEW swings while operating from a single 1.8 V to 5 V power supply (BALL SIDE DOWN) NC = NO CONNECT or from dual ±0.9 V to ±2.5 V power supplies. Figure 3. 6-Ball WLCSP (CB-6-7) Figure 4. 8-Ball WLCSP (CB-8-2) Employing a new circuit technology, these low cost amplifiers BALL A1 offer zero input crossover distortion (excellent PSRR and CMRR INDICATOR performance) and very low bias current, while operating with a OUT D OUT A –IN A supply current of less than 10 μA per amplifier. A1 A2 A3 –IN D V– +IN A This combination of features makes the ADA4505-x amplifiers B1 B2 B3 ideal choices for battery-powered applications because they +IN D +IN B 1 OUT A 14 OUT D minimize errors due to power supply voltage variations over the C1 C3 2 –IN A 13 –IN D lifetime of the battery and maintain high CMRR even for a rail- +IN C V+ –IN B ADA4505-4 3 D1 D2 D3 +IN A 12 +IN D to-rail op amp. TOP VIEW –IN C OUT C OUT B 4 11 V+ V– (Not to Scale) Remote battery-powered sensors, handheld instrumentation E1 E2 E3 5 10 +IN B +IN C and consumer equipment, hazard detectors (for example, smoke, 6 9 –IN B –IN C ADA4505-4 fire, and gas), and patient monitors can benefit from the features TOP VIEW 7 8 OUT B OUT C (BALL SIDE DOWN) of the ADA4505-x amplifiers. Not to Scale The ADA4505-x family is specified for both the industrial Figure 5. 14-Lead TSSOP (RU-14) Figure 6. 14-Ball WLCSP (CB-14-1) temperature range (−40°C to +85°C) and the extended industrial temperature range (−40°C to +125°C). The ADA4505-1 single amplifier is available in a tiny 5-lead SOT-23 and a 6-ball WLCSP. The ADA4505-2 dual amplifier is available in a standard 8-lead MSOP and a 8-ball WLCSP. The ADA4505-4 quad amplifier is available in a 14-lead TSSOP and a 14-ball WLCSP. The ADA4505-x family is a member of a growing series of zero crossover op amps offered by Analog Devices, Inc., including the AD8505/AD8506/AD8508, which also operate from a single 1.8 V to 5 V power supply or from dual ±0.9 V to ±2.5 V power supplies. Rev. D 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 One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. rights of third parties that may result from its use. Specifications subject to change without notice. No Tel: 781.329.4700 www.analog.com license is granted by implication or otherwise under any patent or patent rights of Analog Devices. Fax: 781.461.3113 ©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. 07416-068 07416-001 07416-005 07416-003 07416-061 07416-004 ADA4505-1/ADA4505-2/ADA4505-4 TABLE OF CONTENTS Features .............................................................................................. 1  ESD Caution...................................................................................5  Applications ....................................................................................... 1  Typical Performance Characteristics ..............................................6  General Description ......................................................................... 1  Theory of Operation ...................................................................... 14  Pin Configurations ........................................................................... 1  Applications Information .............................................................. 16  Revision History ............................................................................... 2  Pulse Oximeter Current Source ............................................... 16  Specif ica t ions ..................................................................................... 3  Four-Pole, Low-Pass Butterworth Filter for Glucose Monitor ....................................................................................................... 17  Electrical Characteristics—1.8 V Operation ............................ 3  Outline Dimensions ....................................................................... 18  Electrical Characteristics—5 V Operation................................ 4  Ordering Guide .......................................................................... 21  Absolute Maximum Ratings ............................................................ 5  Thermal Resistance ...................................................................... 5  REVISION HISTORY 7/10—Rev. C to Rev. D 10/08—Rev. 0 to Rev. A Added 6-Ball WLCSP, ADA4505-1 .................................. Universal Added 8-Ball WLCSP (ADA4505-2) and 14-Lead TSSOP Moved Electrical Characteristics—1.8 V Operation Section .... 3 (ADA4505-4) ................................................................. Throughout Changes to Large Signal Voltage Gain Parameter, Table 1 .......... 3 Change to Features Section .............................................................. 1 Moved Electrical Characteristics—5 V Operation Section ....... 4 Added Figure 2 and Figure 3; Renumbered Sequentially ............ 1 Changes to Large Signal Voltage Gain Parameter, Table 2 .......... 4 Changes to Table 1 ............................................................................. 3 Changes to Thermal Resistance Section and Table 4 ................... 5 Changes to Table 2 ............................................................................. 4 Changes to Thermal Resistance Section ........................................ 5 Updated Outline Dimensions ....................................................... 18 Changes to Ordering Guide .......................................................... 21 Changes to Figure 22 and Figure 25................................................ 9 Changes to Figure 40 and Figure 43............................................. 12 7/09—Rev. B to Rev. C Deleted Figure 46 and Figure 48; Renumbered Sequentially ... 13 Added 5-Lead SOT-23 (ADA4505-1) ......................... Throughout Change to Theory of Operation Section ..................................... 14 Changes to Supply Current per Amplifier Parameter, Table 1 ... 3 Changes to Figure 52 ...................................................................... 16 Changes to Supply Current per Amplifier Parameter, Table 2 ... 4 Change to Four-Pole Low-Pass Butterworth Filter Changes to Figure 26 and Figure 29 ............................................... 9 for Glucose Monitor Section ......................................................... 17 Updated Outline Dimensions ....................................................... 18 Changes to Figure 31 and Figure 34 ............................................. 10 Changes to Figure 42 and Figure 45 ............................................. 12 Changes to Ordering Guide .......................................................... 19 Added Figure 49 and Figure 51; Renumbered Sequentially ..... 13 Updated Outline Dimensions ....................................................... 18 7/08—Revision 0: Initial Version Changes to Ordering Guide .......................................................... 20 2/09—Rev. A to Rev. B Added 14-Ball WLCSP (ADA4505-4) ........................ Throughout Changes to Thermal Resistance Section ........................................ 5 Changes to Figure 17, Figure 18, Figure 20, and Figure 21 ......... 8 Changes to Figure 42 and Figure 45 ............................................. 12 Updated Outline Dimensions ....................................................... 18 Changes to Ordering Guide .......................................................... 20 Rev. D | Page 2 of 24 ADA4505-1/ADA4505-2/ADA4505-4 SPECIFICATIONS ELECTRICAL CHARACTERISTICS—1.8 V OPERATION V = 1.8 V, V = V /2, T = 25°C, R = 100 kΩ to GND, unless otherwise specified. SY CM SY A L Table 1. Parameter Symbol Test Conditions/Comments Min Typ Max Unit INPUT CHARACTERISTICS Offset Voltage VOS 0 V ≤ VCM ≤ 1.8 V 0.5 3 mV −40°C ≤ T ≤ +125°C 4 mV A Input Bias Current I 0.5 2 pA B −40°C ≤ TA ≤ +85°C 50 pA −40°C ≤ TA ≤ +125°C 375 pA Input Offset Current IOS 0.05 1 pA −40°C ≤ T ≤ +85°C 25 pA A −40°C ≤ T ≤ +125°C 130 pA A Input Voltage Range −40°C ≤ T ≤ +125°C 0 1.8 V A Common-Mode Rejection Ratio CMRR 0 V ≤ VCM ≤ 1.8 V 85 100 dB −40°C ≤ TA ≤ +85°C 85 dB −40°C ≤ TA ≤ +125°C 80 dB Large Signal Voltage Gain A 0.05 V ≤ V ≤ 1.75 V, 95 115 dB VO OUT R = 100 kΩ to V L CM −40°C ≤ TA ≤ +125°C 95 dB Offset Voltage Drift −40°C ≤ TA ≤ +125°C 2.5 μV/°C ΔVOS/ΔT Input Resistance R 220 GΩ IN Input Capacitance Differential Mode C 2.5 pF INDM Input Capacitance Common Mode C 4.7 pF INCM OUTPUT CHARACTERISTICS Output Voltage High V R = 100 kΩ to GND 1.78 1.79 V OH L −40°C ≤ T ≤ +125°C 1.78 V A RL = 10 kΩ to GND 1.65 1.75 V −40°C ≤ TA ≤ +125°C 1.65 V Output Voltage Low VOL RL = 100 kΩ to VSY 2 5 mV −40°C ≤ T ≤ +125°C 5 mV A R = 10 kΩ to V 12 25 mV L SY −40°C ≤ TA ≤ +125°C 25 mV Short-Circuit Limit ISC VOUT = VSY or GND ±3.8 mA POWER SUPPLY Power Supply Rejection Ratio PSRR VSY = 1.8 V to 5 V 100 110 dB −40°C ≤ TA ≤ +85°C 100 dB −40°C ≤ TA ≤ +125°C 95 dB Supply Current per Amplifier I V = V/2 SY OUT SY ADA4505-1 10 11.5 μA –40°C ≤ T ≤ +125°C 15 μA A ADA4505-2/ADA4505-4 7 10 μA −40°C ≤ TA ≤ +125°C 15 μA DYNAMIC PERFORMANCE Slew Rate SR RL = 100 kΩ, CL = 20 pF, G = 1 6.5 mV/μs Gain Bandwidth Product GBP RL = 1 MΩ, CL = 20 pF, G = 1 50 kHz Phase Margin ΦM RL = 1 MΩ, CL = 20 pF, G = 1 52 Degrees NOISE PERFORMANCE Voltage Noise en p-p f = 0.1 Hz to 10 Hz 2.95 μV p-p Voltage Noise Density en f = 1 kHz 65 nV/√Hz Current Noise Density i f = 1 kHz 20 fA/√Hz n Rev. D | Page 3 of 24 ADA4505-1/ADA4505-2/ADA4505-4 ELECTRICAL CHARACTERISTICS—5 V OPERATION VSY = 5 V, VCM = VSY/2, TA = 25°C, RL = 100 kΩ to GND, unless otherwise specified. Table 2. Parameter Symbol Test Conditions/Comments Min Typ Max Unit INPUT CHARACTERISTICS Offset Voltage VOS 0 V ≤ VCM ≤ 5 V 0.5 3 mV −40°C ≤ TA ≤ +125°C 4 mV Input Bias Current IB 0.5 2 pA −40°C ≤ T ≤ +85°C 50 pA A −40°C ≤ T ≤ +125°C 375 pA A Input Offset Current IOS 0.05 1 pA −40°C ≤ TA ≤ +85°C 25 pA −40°C ≤ TA ≤ +125°C 130 pA Input Voltage Range −40°C ≤ T ≤ +125°C 0 5 V A Common-Mode Rejection Ratio CMRR 0 V ≤ V ≤ 5 V 90 105 dB CM −40°C ≤ T ≤ +85°C 90 dB A −40°C ≤ TA ≤ +125°C 85 dB Large Signal Voltage Gain AVO 0.05 V ≤ VOUT ≤ 4.95 V, 105 120 dB R = 100 kΩ to V L CM −40°C ≤ T ≤ +125°C 100 dB A Offset Voltage Drift −40°C ≤ T ≤ +125°C 2 μV/°C ΔV /ΔT A OS Input Resistance RIN 220 GΩ Input Capacitance Differential Mode CINDM 2.5 pF Input Capacitance Common Mode CINCM 4.7 pF OUTPUT CHARACTERISTICS Output Voltage High VOH RL = 100 kΩ to GND 4.98 4.99 V −40°C ≤ T ≤ +125°C 4.98 V A R = 10 kΩ to GND 4.9 4.95 V L −40°C ≤ T ≤ +125°C 4.9 V A Output Voltage Low VOL RL = 100 kΩ to VSY 2 5 mV −40°C ≤ TA ≤ +125°C 5 mV RL = 10 kΩ to VSY 10 25 mV −40°C ≤ T ≤ +125°C 25 mV A Short-Circuit Limit I V = V or GND ±40 mA SC OUT SY POWER SUPPLY Power Supply Rejection Ratio PSRR V = 1.8 V to 5 V 100 110 dB SY −40°C ≤ T ≤ +85°C 100 dB A −40°C ≤ T ≤ +125°C 95 dB A Supply Current per Amplifier ISY VOUT = VSY/2 ADA4505-1 9 10.5 μA –40°C ≤ T ≤ +125°C 15 μA A ADA4505-2/ADA4505-4 7 10 μA −40°C ≤ T ≤ +125°C 15 μA A DYNAMIC PERFORMANCE Slew Rate SR R = 100 kΩ, C = 20 pF, G = 1 6 mV/μs L L Gain Bandwidth Product GBP R = 1 MΩ, C = 20 pF, G = 1 50 kHz L L Phase Margin ΦM RL = 1 MΩ, CL = 20 pF, G = 1 52 Degrees NOISE PERFORMANCE Voltage Noise e p-p f = 0.1 Hz to 10 Hz 2.95 μV p-p n Voltage Noise Density en f = 1 kHz 65 nV/√Hz Current Noise Density in f = 1 kHz 20 fA/√Hz Rev. D | Page 4 of 24 ADA4505-1/ADA4505-2/ADA4505-4 ABSOLUTE MAXIMUM RATINGS THERMAL RESISTANCE Table 3. Parameter Rating θ is specified for the worst-case conditions, that is, a device JA soldered in a circuit board for surface-mount packages with its Supply Voltage 5.5 V exposed paddle soldered to a pad (if applicable). Simulated Input Voltage ±V ± 0.1 V SY 1 Input Current ±10 mA thermal numbers on a 4-layer (2S/2P) JEDEC standard thermal 2 test board, unless otherwise specified. Differential Input Voltage ±VSY Output Short-Circuit Duration to GND Indefinite Table 4. Storage Temperature Range −65°C to +150°C Package Type θJA θJC Unit Operating Temperature Range −40°C to +125°C 5-Lead SOT-23 (RJ-5) 190 92 °C/W Junction Temperature Range −65°C to +150°C 6-Ball WLCSP (CB-6-7) 105 2.6 °C/W Lead Temperature (Soldering, 60 sec) 300°C 8-Lead MSOP (RM-8) 142 45 °C/W 1 Input pins have clamp diodes to the supply pins. Limit input current to 10 mA 8-Ball WLCSP (CB-8-2) 82 N/A °C/W or less whenever the input signal exceeds the power supply rail by 0.1 V. 14-Lead TSSOP (RU-14) 112 35 °C/W 2 Differential input voltage is limited to 5 V or the supply voltage, whichever is less. 14-Ball WLCSP (CB-14-1) 64 N/A °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 ESD CAUTION 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. D | Page 5 of 24 ADA4505-1/ADA4505-2/ADA4505-4 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, unless otherwise noted. 140 140 V = 1.8V V = 5V SY SY V = V /2 V = V /2 CM SY CM SY 120 120 100 100 80 80 60 60 40 40 20 20 0 0 –3.0 –2.5 –2.0 –1.5 –1.0 –0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 –3.0 –2.5 –2.0 –1.5 –1.0 –0.5 0 0.5 1.0 1.5 2.0 2.5 3.0 V (mV) V (mV) OS OS Figure 7. Input Offset Voltage Distribution Figure 10. Input Offset Voltage Distribution 14 14 V = 1.8V V = 5V SY SY –40°C ≤ T ≤ 125°C –40°C ≤ T ≤ 125°C A A 12 12 10 10 8 8 6 6 4 4 2 2 0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 TCV (µV/°C) TCV (µV/°C) OS OS Figure 8. Input Offset Voltage Drift Distribution Figure 11. Input Offset Voltage Drift Distribution 1500 1500 V = 1.8V V = 5V SY SY 1000 1000 DEVICE 1 DEVICE 1 DEVICE 2 DEVICE 2 500 500 DEVICE 3 DEVICE 3 DEVICE 4 DEVICE 4 DEVICE 5 DEVICE 5 0 0 DEVICE 6 DEVICE 6 DEVICE 7 DEVICE 7 DEVICE 8 DEVICE 8 –500 –500 DEVICE 9 DEVICE 9 DEVICE 10 DEVICE 10 –1000 –1000 –1500 –1500 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 01 2 3 4 5 V (V) V (V) CM CM Figure 9. Input Offset Voltage vs. Common-Mode Voltage Figure 12. Input Offset Voltage vs. Common-Mode Voltage Rev. D | Page 6 of 24 V (µV) OS NUMBER OF AMPLIFIERS NUMBER OF AMPLIFIERS 07416-011 07416-009 07416-007 V (µV) OS NUMBER OF AMPLIFIERS NUMBER OF AMPLIFIERS 07416-012 07416-010 07416-008 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 1000 1000 V = 1.8V V = 5V SY I SY I B+ B+ I I B– B– 100 100 10 10 1 1 0.1 0.1 0 25 50 75 100 125 0 25 50 75 100 125 TEMPERATURE (°C) TEMPERATURE (°C) Figure 13. Input Bias Current vs. Temperature Figure 16. Input Bias Current vs. Temperature 1000 1000 V = 1.8V V = 5V SY SY I AND I I AND I B+ B– B+ B– 125°C 125°C 100 100 105°C 105°C 10 10 85°C 85°C 1 1 25°C 25°C 0.1 0.1 0 0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 0 1 2 345 V (V) V (V) CM CM Figure 14. Input Bias Current vs. Common-Mode Voltage and Temperature Figure 17. Input Bias Current vs. Common-Mode Voltage and Temperature 10k 10k V = 5V V = 1.8V SY SY 1k 1k 100 100 10 10 1 1 –40°C –40°C +25°C +25°C 0.1 0.1 +85°C +85°C +125°C +125°C 0.01 0.01 0.001 0.01 0.1 110 100 0.001 0.01 0.1 110 100 LOAD CURRENT (mA) LOAD CURRENT (mA) Figure 15. Output Voltage (VOH) to Supply Rail vs. Load Current Figure 18. Output Voltage (VOH) to Supply Rail vs. Load Current and Temperature and Temperature Rev. D | Page 7 of 24 OUTPUT VOLTAGE (V ) TO SUPPLY RAIL (mV) OH I (pA) I (pA) B B 07416-014 07416-013 07416-017 OUTPUT VOLTAGE (V ) TO SUPPLY RAIL (mV) OH I (pA) I (pA) B B 07416-016 07416-015 07416-018 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 10k 10k V = 1.8V V = 5V SY SY 1k 1k 100 100 10 10 1 1 –40°C –40°C +25°C +25°C 0.1 0.1 +85°C +85°C +125°C +125°C 0.01 0.01 0.001 0.01 0.1 1 10 100 0.001 0.01 0.1 1 10 100 LOAD CURRENT (mA) LOAD CURRENT (mA) Figure 19. Output Voltage (V ) to Supply Rail vs. Load Current Figure 22. Output Voltage (V ) to Supply Rail vs. Load Current OL OL and Temperature and Temperature 1.800 5.000 R = 100kΩ L R = 100kΩ L 4.995 1.795 4.990 1.790 4.985 R = 10kΩ L 1.785 R = 10kΩ L 4.980 1.780 4.975 V = 1.8V V = 5V SY SY 1.775 4.970 –40 –25 –10 5 20 35 50 65 80 95 110 125 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) Figure 20. Output Voltage (VOH) vs. Temperature Figure 23. Output Voltage (VOH) vs. Temperature 25 25 V = 5V SY V = 1.8V SY 20 20 R = 10kΩ L R = 10kΩ L 15 15 10 10 5 5 R = 100kΩ R = 100kΩ L L 0 0 –40 –25 –10 5 203550658095 110 125 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) TEMPERATURE (°C) Figure 24. Output Voltage (V ) vs. Temperature OL Figure 21. Output Voltage (VOL) vs. Temperature Rev. D | Page 8 of 24 OUTPUT VOLTAGE [V ] (V) OUTPUT VOLTAGE (V ) TO SUPPLY RAIL (mV) OH OL OUTPUT VOLTAGE [V ] (mV) OL 07416-023 07416-021 07416-019 OUTPUT VOLTAGE [V ] (V) OUTPUT VOLTAGE (V ) TO SUPPLY RAIL (mV) OL OH OUTPUT VOLTAGE [V ] (mV) OL 07416-024 07416-022 07416-020 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 100 225 100 225 V = 1.8V SY V = 5V SY 80 180 80 180 60 135 60 135 PHASE PHASE 40 90 40 90 20 45 20 45 GAIN GAIN 0 0 0 0 –20 –45 –20 –45 –40 –90 –40 –90 –60 –135 –60 –135 –80 –180 –80 –180 –100 –225 –100 –225 100 1k 10k 100k 1M 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 25. Open-Loop Gain and Phase vs. Frequency Figure 28. Open-Loop Gain and Phase vs. Frequency 60 60 V = 1.8V V = 5V SY SY 50 50 G = –100 G = –100 40 40 30 30 G = –10 G = –10 20 20 10 10 G = –1 G = –1 0 0 –10 –10 –20 –20 –30 –30 –40 –40 –50 –50 –60 –60 100 1k 10k 100k 1M 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 26. Closed-Loop Gain vs. Frequency Figure 29. Closed-Loop Gain vs. Frequency 10k 10k V = 5V V = 1.8V SY SY G = –10 G = –10 G = –100 1k 1k G = –100 G = –1 G = –1 100 100 10 10 1 1 0.1 0.1 10 100 1k 10k 100k 1M 10 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 27. Output Impedance vs. Frequency Figure 30. Output Impedance vs. Frequency Rev. D | Page 9 of 24 OPEN-LOOP GAIN (dB) Z (Ω) CLOSED-LOOP GAIN (dB) OUT 07416-062 07416-027 PHASE (Degrees) 07416-025 OPEN-LOOP GAIN (dB) Z (Ω) CLOSED-LOOP GAIN (dB) OUT 07416-063 07416-028 PHASE (Degrees) 07416-026 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 120 120 V = 1.8V V = 5V SY SY 100 100 80 80 60 60 40 40 20 20 0 0 100 1k 10k 100k 1M 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 31. CMRR vs. Frequency Figure 34. CMRR vs. Frequency 120 120 V = 5V V = 1.8V SY SY 100 100 80 80 60 60 40 40 20 20 PSRR+ PSRR+ PSRR– PSRR– 0 0 10 100 1k 10k 100k 1M 10 100 1k 10k 100k 1M FREQUENCY (Hz) FREQUENCY (Hz) Figure 32. PSRR vs. Frequency Figure 35. PSRR vs. Frequency 1k 140 1.8V ≤ V ≤ 5V SY 130 V = 5V SY 120 110 100 V = 1.8V SY 100 90 10 80 –40 –25 –10 5 20 35 50 65 80 95 110 125 1 10 100 1000 FREQUENCY (Hz) TEMPERATURE (°C) Figure 33. PSRR vs. Temperature Figure 36. Voltage Noise Density vs. Frequency Rev. D | Page 10 of 24 PSRR (dB) PSRR (dB) CMRR (dB) 07416-033 07416-031 07416-035 e (nV/√Hz) n PSRR (dB) CMRR (dB) 07416-032 07416-034 07416-050 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 80 80 V = 1.8V V = 5V SY SY V = 10mV p-p V = 10mV p-p IN IN 70 70 R = 100kΩ R = 100kΩ L L 60 60 50 50 40 40 30 30 OS+ 20 20 OS– OS+ 10 10 OS– 0 0 10 100 1000 10 100 1000 CAPACITANCE (pF) CAPACITANCE (pF) Figure 37. Small Signal Overshoot vs. Load Capacitance Figure 40. Small Signal Overshoot vs. Load Capacitance T T LOAD = 100kΩ || 100pF LOAD = 100kΩ || 100pF V = 5V V = 1.8V SY SY 3.959V p-p 1.490V p-p TIME (200µs/DIV) TIME (200µs/DIV) Figure 38. Large Signal Transient Response Figure 41. Large Signal Transient Response T T LOAD = 100kΩ || 100pF LOAD = 100kΩ || 100pF V = 1.8V V = 5V SY SY TIME (200µs/DIV) TIME (200µs/DIV) Figure 39. Small Signal Transient Response Figure 42. Small Signal Transient Response Rev. D | Page 11 of 24 OVERSHOOT (%) VOLTAGE (2mV/DIV) VOLTAGE (500mV/DIV) 07416-040 07416-038 07416-036 OVERSHOOT (%) VOLTAGE (2mV/DIV) VOLTAGE (1V/DIV) 07416-041 07416-039 07416-037 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 35 40 35 30 ADA4505-4 ADA4505-4, V = 1.8V SY 30 25 ADA4505-4, V = 5V SY 25 20 ADA4505-2, V = 1.8V SY 20 ADA4505-2 15 15 ADA4505-2, V = 5V SY ADA4505-1, V = 1.8V ADA4505-1 SY 10 10 ADA4505-1, V = 5V SY 5 5 0 0 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 –40 –25 –10 5 20 35 50 65 80 95 110 125 V (V) TEMPERATURE (°C) SY Figure 46. Total Supply Current vs. Temperature Figure 43. Supply Current vs. Supply Voltage V = 5V V = 1.8V SY SY 2.95µV p-p 2.95µV p-p TIME (s) TIME (s) Figure 47. Input Voltage Noise, 0.1 Hz to 10 Hz Noise Figure 44. Input Voltage Noise, 0.1 Hz to 10 Hz Noise 0 0 V = 5V V = 1.8V SY SY V = 1V p-p V = 0.5V p-p IN IN R = 100kΩ R = 100kΩ L L V = 2V p-p V = 1V p-p IN IN –20 –20 G = –100 G = –100 V = 3V p-p V = 1.7V p-p IN IN V = 4V p-p IN 100kΩ 100kΩ V = 4.99V p-p IN –40 –40 1kΩ 1kΩ –60 –60 –80 –80 –100 –100 –120 –120 –140 –140 100 1k 10k 100k 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) Figure 48. Channel Separation vs. Frequency Figure 45. Channel Separation vs. Frequency Rev. D | Page 12 of 24 CHANNEL SEPARATION (dB) I (μA) SY INPUT VOLTAGE NOISE (0.5µV/DIV) 07416-052 07416-057 07416-064 CHANNEL SEPARATION (dB) I (μA) SY INPUT VOLTAGE NOISE (0.5µV/DIV) 07416-053 07416-058 07416-065 ADA4505-1/ADA4505-2/ADA4505-4 T = 25°C, unless otherwise noted. A 1.8 6 V = 1.8V V = 5V SY SY V = 1.7V V = 4.9V IN IN G = 1 G = 1 1.5 5 R = 100kΩ R = 100kΩ L L 1.2 4 0.9 3 0.6 2 0.3 1 0 0 10 100 1k 10k 100k 10 100 1k 10k 100k FREQUENCY (Hz) FREQUENCY (Hz) Figure 49. Output Swing vs. Frequency Figure 51. Output Swing vs. Frequency V = ±0.9V SY V = ±2.5V SY G = 1 G = 1 R = 100kΩ L R = 100kΩ L C = NO LOAD L C = NO LOAD L V IN V OUT V IN 2 1 V OUT TIME (400µs/DIV) TIME (400µs/DIV) Figure 50. No Phase Reversal Figure 52. No Phase Reversal Rev. D | Page 13 of 24 OUTPUT SWING (V) 07416-066 07416-059 OUTPUT SWING (V) 07416-067 07416-060 ADA4505-1/ADA4505-2/ADA4505-4 THEORY OF OPERATION V DD The ADA4505-1/ADA4505-2/ADA4505-4 are unity-gain stable CMOS rail-to-rail input/output operational amplifiers designed to optimize performance in current consumption, PSRR, CMRR, V BIAS and zero crossover distortion, all embedded in a small package. The typical offset voltage is 500 μV, with a low peak-to-peak voltage noise of 2.95 μV from 0.1 Hz to 10 Hz and a voltage noise density of 65 nV/√Hz at 1 kHz. V V IN+ IN– Q3 Q1 Q2 Q4 The ADA4505-x amplifiers are designed to solve two key I I B problems in low voltage battery-powered applications: battery B voltage decrease over time and rail-to-rail input stage distortion. In battery-powered applications, the supply voltage available to V SS the IC is the voltage of the battery. Unfortunately, the voltage of Figure 53. Typical Dual Differential Pair Input Stage Op Amp a battery decreases as it discharges itself through the load. This (Dual PMOS Q1 and Q2 Transistors Form the Lower End of the Input Voltage voltage drop over the lifetime of the battery causes an error in Range; Dual NMOS Q3 and Q4 Transistors Form the Upper End) the output of the op amps. Some applications requiring precision 300 measurements during the entire lifetime of the battery use voltage V = 5V SY 250 T = 25°C A regulators to power up the op amps as a solution. If a design 200 uses standard battery cells, the op amps experience a supply 150 voltage change from roughly 3.2 V to 1.8 V during the lifetime 100 of the battery. This means that for a PSRR of 70 dB minimum in 50 a typical op amp, the input-referred offset error is approximately 0 440 μV. If the same application uses the ADA4505-x with a 100 dB –50 minimum PSRR, the error is only 14 μV. It is possible to calibrate –100 this error out or to use an external voltage regulator to power –150 the op amp, but these solutions can increase system cost and –200 complexity. The ADA4505-x amplifiers solve the impasse with –250 no additional cost or error-nullifying circuitry. –300 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 The second problem with battery-powered applications is the V (V) CM distortion caused by the standard rail-to-rail input stage. Using Figure 54. Typical Input Offset Voltage vs. Common-Mode Voltage a CMOS nonrail-to-rail input stage (that is, a single differential Response in a Dual Differential Pair Input Stage Op Amp (Powered by a 5 V Supply; Results of Approximately 100 Units per Graph Are Displayed) pair) limits the input voltage to approximately one V (gate- GS source voltage) away from one of the supply lines. Because VGS This distortion forces the designer to devise impractical ways for normal operation is commonly over 1 V, a single differential to avoid the crossover distortion areas, thereby narrowing the pair, input stage op amp greatly restricts the allowable input common-mode dynamic range of the operational amplifier. The voltage range when using a low supply voltage. This limitation ADA4505-x family solves this crossover distortion problem by restricts the number of applications where the nonrail-to-rail using an on-chip charge pump to power the input differential input op amp was originally intended to be used. To solve this pair. The charge pump creates a supply voltage higher than the problem, a dual differential pair input stage is usually implemented voltage of the battery, allowing the input stage to handle a wide (see Figure 53); however, this technique has its own drawbacks. range of input signal voltages without using a second differential pair. With this solution, the input voltage can vary from one One differential pair amplifies the input signal when the common- supply extreme to the other with no distortion, thereby restoring mode voltage is on the high end, whereas the other pair amplifies the full common-mode dynamic range of the op amp. the input signal when the common-mode voltage is on the low end. This method also requires control circuitry to operate the The charge pump has been carefully designed so that switching two differential pairs appropriately. Unfortunately, this topology noise components at any frequency, both within and beyond the leads to a very noticeable and undesirable problem; if the signal amplifier bandwidth, are much lower than the thermal noise floor. level moves through the range where one input stage turns off and Therefore, the spurious-free dynamic range (SFDR) is limited the other one turns on, noticeable distortion occurs (see Figure 54). only by the input signal and the thermal or flicker noise. There is no intermodulation between input signal and switching noise. Rev. D | Page 14 of 24 V (µV) OS 07416-044 07416-043 ADA4505-1/ADA4505-2/ADA4505-4 300 Figure 55 displays a typical front-end section of an operational V = 5V SY 250 amplifier with an on-chip charge pump. T = 25°C A 200 V = POSITIVE PUMPED VOLTAGE = V + 1.8V PP DD 150 V PP V DD 100 V BIAS 50 0 CASCODE –50 STAGE Q2 –IN +IN Q1 AND –100 RAIL-TO-RAIL OUT OUTPUT –150 STAGE –200 –250 –300 V SS 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 V (V) CM Figure 55. Typical Front-End Section of an Op Amp with Embedded Charge Pump Figure 56. Input Offset Voltage vs. Input Common-Mode Voltage Response (Powered by a 5 V Supply; Results of Two Units Are Displayed) Figure 56 shows the typical response of two devices from Figure 12, This solution improves the CMRR performance tremendously. which shows the input offset voltage vs. input common-mode For example, if the input varies from rail to rail on a 2.5 V voltage for 10 devices. Figure 56 is expanded to make it easier to supply rail, using a part with a CMRR of 70 dB minimum, compare with Figure 54, which shows the typical input offset an input-referred error of 790 μV is introduced. Another part voltage vs. common-mode voltage response in a dual differential with a CMRR of 52 dB minimum generates a 6.3 mV error. pair input stage op amp. The ADA4505-x family CMRR of 90 dB minimum causes only a 79 μV error. As with the PSRR error, there are complex ways to minimize this error, but the ADA4505-x family solves this problem without incurring unnecessary circuitry complexity or increased cost. Rev. D | Page 15 of 24 07416-045 V (µV) OS 07416-046 ADA4505-1/ADA4505-2/ADA4505-4 APPLICATIONS INFORMATION +5V PULSE OXIMETER CURRENT SOURCE C2 CONNECT TO RED LED 0.1µF A pulse oximeter is a noninvasive medical device used for +5V U2 continuously measuring the percentage of hemoglobin (Hb) C1 U1 ADG733 0.1µF 16 1/2 saturated with oxygen and the pulse rate of a patient. Hemo- +5V 62.5mA ADA4505-2 V DD globin that is carrying oxygen (oxyhemoglobin) absorbs light in S1A 12 R4 8 14 D1 R2 the infrared (IR) region of the spectrum; hemoglobin that is not V 5 53.6kΩ OUT1 S1B 13 22Ω V+ 7 carrying oxygen (deoxyhemoglobin) absorbs visible red (R) light. V = 1.25V REF V– S2A 2 6 U3 In pulse oximetry, a clip containing two LEDs (sometimes more, Q1 4 15 D2 ADR1581 IRLMS2002 S2B 1 C3 depending on the complexity of the measurement algorithm) and 22pF S3A 5 the light sensor (photodiode) is placed on the finger or earlobe R3 4 D3 1kΩ of the patient. One LED emits red light (600 nm to 700 nm), and S3B 3 R1 the other emits light in the near IR (800 nm to 900 nm) region. RED CURRENT 9 20Ω A2 SOURCE 10 0.1% A1 The clip is connected by a cable to a processor unit. The LEDs 1/4 W MIN 11 8 A0 GND are rapidly and sequentially excited by two current sources (one 6 EN for each LED) whose dc levels depend on the LED being driven, V SS based on manufacturer requirements; the detector is synchronized CONNECT TO INFRARED LED 7 to capture the light from each LED as it is transmitted through +5V U1 the tissue. 101mA 1/2 ADA4505-2 An example design of a dc current source driving the red and 8 R6 I_BIT2 3 V OUT2 infrared LEDs is shown in Figure 57. These dc current sources 22Ω V+ I_BIT1 1 I_BIT0 allow 62.5 mA and 101 mA to flow through the red and infrared V– I_ENA 2 Q2 4 LEDs, respectively. First, to prolong battery life, the LEDs are IRLMS2002 C4 driven only when needed. One third of the ADG733 SPDT 22pF R7 analog switch is used to disconnect/connect the 1.25 V voltage 1kΩ reference from/to each current circuit. When driving the LEDs, R5 INFRARED CURRENT 12.4Ω the ADR1581 1.25 V voltage reference is buffered by one half of SOURCE 0.1% the ADA4505-2; the presence of this voltage on the noninverting 1/2 W MIN input forces the output of the op amp (due to the negative feed- Figure 57. Pulse Oximeter Red and Infrared Current Sources Using the back) to maintain a level that causes its inverting input to track ADA4505-2 as a Buffer to the Voltage Reference Device the noninverting pin. Therefore, the 1.25 V appears in parallel with the 20 Ω R1 or 12.4 Ω R5 current source resistor, creating the flow of the 62.5 mA or 101 mA current through the red or infrared LED as the output of the op amp turns on the Q1 or Q2 N-MOSFET IRLMS2002. The maximum total quiescent currents for one half of the ADA4505-2, the ADR1581, and the ADG733 are 15 μA, 70 μA, and 1 μA, respectively, for a total of 86 μA current consumption (430 μW power consumption) per circuit, which is good for a system powered by a battery. If the accuracy and temperature drift of the total design need improvement, use a more accurate and low temperature coefficient drift voltage reference and current source resistor. C3 and C4 are used to improve stabilization of U1; R3 and R7 are used to provide some current limit into the U1 inverting pin; and R2 and R6 are used to slow the rise time of the N-MOSFET when it turns on. These elements may not be needed, or some bench adjustments may be required. Rev. D | Page 16 of 24 07416-047 ADA4505-1/ADA4505-2/ADA4505-4 Another consideration is operation from a 3.3 V battery. Glucose FOUR-POLE, LOW-PASS BUTTERWORTH FILTER signal currents are usually less than 3 μA full scale; therefore, FOR GLUCOSE MONITOR the I-to-V converter requires low input bias current. The There are several methods of glucose monitoring: spectroscopic ADA4505-x family is an excellent choice because it provides absorption of infrared light in the 2 μm to 2.5 μm range, reflec- 0.5 pA typical and 2 pA maximum input bias current at ambient tance spectrophotometry, and the amperometric type using temperature. electrochemical strips with glucose oxidase enzymes. The A low-pass filter with a cutoff frequency of 80 Hz to 100 Hz is amperometric type generally uses three electrodes: a reference desirable in a glucose meter device to remove extraneous noise; electrode, a control electrode, and a working electrode. Although this can be a simple two-pole or four-pole Butterworth filter. this is a very old and widely used technique, signal-to-noise Low power op amps with bandwidths of 50 kHz to 500 kHz ratio and repeatability can be improved using the ADA4505-x should be adequate. The ADA4505-x family, with its 50 kHz GBP family, with its low peak-to-peak voltage noise of 2.95 μV from and 7 μA typical current consumption, meets these requirements. 0.1 Hz to 10 Hz and voltage noise density of 65 nV/√Hz at 1 kHz. A circuit design of a four-pole Butterworth filter (preceded by a one-pole low-pass filter) is shown in Figure 58. With a 3.3 V battery, the total power consumption of this design is 198 μW typical at ambient temperature. C1 1000pF R1 5MΩ +3.3V WORKING +3.3V U1 1/2 3 8 CONTROL R2 R3 U2 ADA4505-2 +3.3V V+ 22.6kΩ 22.6kΩ 1/2 8 1 5 R4 R5 ADA4505-2 V– C3 V+ 22.6kΩ 22.6kΩ REFERENCE 8 2 U1 0.047µF 7 3 4 1/2 V– C5 V+ ADA4505-2 6 0.047µF 1 4 V OUT V– C2 2 4 0.1µF C4 0.1µF DUPLICATE OF CIRCUIT ABOVE Figure 58. Four-Pole Butterworth Filter That Can Be Used in a Glucose Meter Rev. D | Page 17 of 24 07416-048 ADA4505-1/ADA4505-2/ADA4505-4 OUTLINE DIMENSIONS 3.00 2.90 2.80 5 4 3.00 1.70 2.80 1.60 2.60 1.50 12 3 0.95 BSC 1.90 BSC 1.30 1.15 0.90 0.20 MAX 1.45 MAX 0.08 MIN 0.95 MIN 0.55 0.15 MAX 10° 0.45 SEATING 0.20 0.05 MIN 5° 0.50 MAX 0.35 PLANE BSC 0° 0.35 MIN COMPLIANT TO JEDEC STANDARDS MO-178-AA Figure 59. 5-Lead Small Outline Transistor Package [SOT-23] (RJ-5) Dimensions shown in millimeters 0.645 0.600 0.945 0.415 0.555 0.905 0.400 SEATING 0.865 0.385 PLANE 2 1 A 0.287 BALL A1 1.425 0.267 0.80 IDENTIFIER 1.385 BSC 0.247 B 1.345 0.40 BSC C TOP VIEW 0.05 NOM 0.40 BSC (BALL SIDE DOWN) 0.230 COPLANARITY BOTTOM VIEW 0.200 (BALL SIDE UP) 0.170 Figure 60. 6-Ball Wafer Level Chip Scale Package [WLCSP] (CB-6-7) Dimensions shown in millimeters Rev. D | Page 18 of 24 121608-A 081709-A ADA4505-1/ADA4505-2/ADA4505-4 0.650 0.595 1.460 0.540 1.420 SQ SEATING 1.380 3 2 1 PLANE 0.340 A BALL 1 0.320 IDENTIFIER 0.300 B 0.50 C BALL PITCH TOP VIEW BOTTOM VIEW 0.380 (BALL SIDE UP) 0.355 0.270 0.330 0.240 0.210 COPLANARITY 0.075 Figure 61. 8-Ball Wafer Level Chip Scale Package [WLCSP] (CB-8-2) Dimensions shown in millimeters 3.20 3.00 2.80 8 5 5.15 3.20 4.90 3.00 4.65 1 2.80 4 PIN 1 IDENTIFIER 0.65 BSC 0.95 15° MAX 0.85 1.10 MAX 0.75 0.80 0.15 0.23 6° 0.55 0.40 0.05 0.09 0° 0.40 0.25 COPLANARITY 0.10 COMPLIANT TO JEDEC STANDARDS MO-187-AA Figure 62. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters Rev. D | Page 19 of 24 100709-B 011008-B ADA4505-1/ADA4505-2/ADA4505-4 5.10 5.00 4.90 14 8 4.50 6.40 4.40 BSC 4.30 1 7 PIN 1 0.65 BSC 1.05 1.20 1.00 0.20 MAX 0.80 0.09 0.75 0.15 8° 0.60 SEATING 0° 0.05 0.45 0.30 PLANE COPLANARITY 0.19 0.10 COMPLIANT TO JEDEC STANDARDS MO-153-AB-1 Figure 63. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters 0.650 0.25 0.595 1.50 BSC 0.25 0.540 BSC 1.46 0.25 0.25 1.42 BSC SEATING BSC 3 2 1 PLANE A BALL 1 0.50 BSC IDENTIFIER B 3.00 0.50 BSC 2.96 2.00 0.340 C BSC 2.92 0.320 0.50 BSC 0.300 D E 0.50 BSC TOP VIEW BOTTOM VIEW 0.10 MAX 0.380 (BALL SIDE UP) (BALL SIDE DOWN) COPLANARITY 0.355 1.00 0.270 0.330 BSC 0.240 0.210 Figure 64. 14-Ball Wafer Level Chip Scale Package [WLCSP] (CB-14-1) Dimensions shown in millimeters Rev. D | Page 20 of 24 061908-A 061208-A ADA4505-1/ADA4505-2/ADA4505-4 ORDERING GUIDE 1 Model Temperature Range Package Description Package Option Branding ADA4505-1ARJZ-R2 −40°C to +125°C 5-Lead SOT-23 RJ-5 A2D ADA4505-1ARJZ-RL −40°C to +125°C 5-Lead SOT-23 RJ-5 A2D ADA4505-1ARJZ-R7 −40°C to +125°C 5-Lead SOT-23 RJ-5 A2D ADA4505-1ACBZ-R7 −40°C to +125°C 6-Ball WLCSP CB-6-7 A2F ADA4505-1ACBZ-RL −40°C to +125°C 6-Ball WLCSP CB-6-7 A2F ADA4505-2ACBZ-RL −40°C to +125°C 8-Ball WLCSP CB-8-2 A21 ADA4505-2ACBZ-R7 −40°C to +125°C 8-Ball WLCSP CB-8-2 A21 ADA4505-2ARMZ −40°C to +125°C 8-Lead MSOP RM-8 A21 ADA4505-2ARMZ-RL −40°C to +125°C 8-Lead MSOP RM-8 A21 ADA4505-4ARUZ −40°C to +125°C 14-Lead TSSOP RU-14 ADA4505-4ARUZ-RL −40°C to +125°C 14-Lead TSSOP RU-14 ADA4505-4ACBZ-RL −40°C to +125°C 14-Ball WLCSP CB-14-1 A2A ADA4505-4ACBZ-R7 −40°C to +125°C 14-Ball WLCSP CB-14-1 A2A 1 Z = RoHS Compliant Part. Rev. D | Page 21 of 24 ADA4505-1/ADA4505-2/ADA4505-4 NOTES Rev. D | Page 22 of 24 ADA4505-1/ADA4505-2/ADA4505-4 NOTES Rev. D | Page 23 of 24 ADA4505-1/ADA4505-2/ADA4505-4 NOTES ©2008–2010 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D07416-0-7/10(D) Rev. D | Page 24 of 24