High Speed, Rail-to-Rail Output Op Amps with Ultralow Power-Down ADA4850-1/ADA4850-2 PIN CONFIGURATIONS Ultralow power-down current: 150 nA/amplifier maximum Low quiescent current: 2.4 mA/amplifier High speed 175 MHz, −3 dB bandwidth 220 V/μs slew rate 85 ns settling time to 0.1% Excellent video specifications 0.1 dB flatness: 14 MHz Differential gain: 0.12% Differential phase: 0.09° Single-supply operation: 2.7 V to 6 V Rail-to-rail output Output swings to within 80 mV of either rail Low voltage offset: 0.6 mV ADA4850-1 POWER DOWN 1 8 +VS NC 2 7 OUTPUT –IN 3 6 NC +IN 4 5 –VS 05320-106 FEATURES NC = NO CONNECT 13 PD2 14 PD1 15 NC 16 NC Figure 1. 8-Lead, 3 mm × 3 mm LFCSP ADA4850-2 12 +VS VOUT1 1 APPLICATIONS –IN1 2 11 VOUT2 +IN1 3 10 –IN2 –VS 4 +IN2 05320-043 NC 8 NC 6 NC 7 9 NC 5 Portable multimedia players Video cameras Digital still cameras Consumer video Clock buffers NC = NO CONNECT Figure 2. 16-Lead, 3 mm × 3 mm LFCSP GENERAL DESCRIPTION 1 –1 –2 –3 –4 G = +1 VS = 5V RL = 1kΩ VOUT = 0.1V p-p –5 The ADA4850 family provides users with a true single-supply capability, allowing input signals to extend 200 mV below the negative rail and to within 2.2 V of the positive rail. The output of the amplifier can swing within 80 mV of either supply rail. With its combination of low price, excellent differential gain (0.12%), differential phase (0.09°), and 0.1 dB flatness out to 14 MHz, these amplifiers are ideal for video applications. 0 –6 1 10 100 FREQUENCY (MHz) 1000 05320-054 The ADA4850-1/ADA4850-2 are designed to operate at supply voltages as low as 2.7 V and up to 6 V at 2.4 mA of supply current per amplifier. In power-down mode, the supply current is less than 150 nA, ideal for battery-powered applications. 2 CLOSED-LOOP GAIN (dB) The ADA4850-1/ADA4850-21 are low price, high speed, voltage feedbacks rail-to-rail output op amps with ultralow powerdown. Despite their low price, the ADA4850-1/ADA4850-2 provide excellent overall performance and versatility. The 175 MHz, −3 dB bandwidth and 220 V/μs slew rate make these amplifiers well-suited for many general-purpose, high speed applications. Figure 3. Small Signal Frequency Response 1 Patents pending. The ADA4850-1/ADA4850-2 are designed to work in the extended temperature range of −40°C to +125°C. 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 ©2005–2007 Analog Devices, Inc. All rights reserved. ADA4850-1/ADA4850-2 TABLE OF CONTENTS Features .............................................................................................. 1 ESD Caution...................................................................................5 Applications....................................................................................... 1 Typical Performance Characteristics ..............................................6 Pin Configurations ........................................................................... 1 Circuit Description......................................................................... 12 General Description ......................................................................... 1 Headroom and Overdrive Recovery Considerations ............ 12 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies........................................................................................ 13 Specifications with +3 V Supply................................................. 3 Power-Down Pins....................................................................... 13 Specifications with +5 V Supply................................................. 4 Outline Dimensions ....................................................................... 14 Absolute Maximum Ratings............................................................ 5 Ordering Guide .......................................................................... 14 Thermal Resistance ...................................................................... 5 REVISION HISTORY 12/07—Rev. A to Rev. B Changes to Applications .................................................................. 1 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 14 4/05—Rev. 0 to Rev. A Added ADA4850-1.............................................................Universal Added 8-Lead LFCSP.........................................................Universal Changes to Features.......................................................................... 1 Changes to General Description .................................................... 1 Changes to Figure 3.......................................................................... 1 Changes to Table 1............................................................................ 3 Changes to Table 2............................................................................ 4 Changes to Power-Down Pins Section and Table 5 ................... 13 Updated Outline Dimensions ....................................................... 14 Changes to Ordering Guide .......................................................... 14 2/05—Revision 0: Initial Version Rev. B | Page 2 of 16 ADA4850-1/ADA4850-2 SPECIFICATIONS SPECIFICATIONS WITH +3 V SUPPLY TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted. Table 1. Parameter DYNAMIC PERFORMANCE −3 dB Bandwidth Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Harmonic Distortion (dBc) HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase DC PERFORMANCE Input Offset Voltage Input Offset Voltage Drift Input Bias Current Input Bias Current Drift Input Bias Offset Current Open-Loop Gain INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Input Overdrive Recovery Time (Rise/Fall) Common-Mode Rejection Ratio POWER-DOWN Power-Down Input Voltage Turn-Off Time Turn-On Time Power-Down Bias Current/ Power Down Pin Enabled Power-Down OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range 1 Quiescent Current/Amplifier Quiescent Current (Power-Down)/Amplifier Positive Power Supply Rejection Negative Power Supply Rejection 1 Conditions Min Typ Max Unit G = +1, VO = 0.1 V p-p G = +2, VO = 0.5 V p-p, RL = 150 Ω G = +2, VO = 0.5 V p-p, RL = 150 Ω G = +2, VO = 1 V step G = +2, VO = 1 V step, RL = 150 Ω 160 45 14 110 80 MHz MHz MHz V/μs ns fC = 1 MHz, VO = 2 V p-p, G = +3, RL = 150 Ω f = 100 kHz f = 100 kHz G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p G = +3, NTSC, RL = 150 Ω, VO = 2 V p-p −72/−77 10 2.5 0.2 0.2 dBc nV/√Hz pA/√Hz % Degrees VO = 0.25 V to 0.75 V 78 0.6 4 2.4 4 30 100 −76 0.5/5.0 1.2 −0.2 to +0.8 60/50 −108 MΩ pF V ns dB Power-down ADA4850-1/ADA4850-2 Enabled ADA4850-1/ADA4850-2 <0.7/<0.6 >0.8/>1.7 0.7 60 V V μs ns Power-down = 3 V Power-down = 0 V 37 0.01 Differential/common-mode VIN = +3.5 V to −0.5 V, G = +1 VCM = 0.5 V VIN = +0.7 V to −0.1 V, G = +5 0.06 to 2.83 Sinking/sourcing For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section. Rev. B | Page 3 of 16 −83 −83 4.4 55 0.2 70/100 0.03 to 2.92 105/74 2.7 +VS = +3 V to +4 V, −VS = 0 V +VS = +3 V, −VS = 0 V to –1 V 4.1 2.4 15 −100 −102 mV μV/°C μA nA/°C nA dB μA μA ns V mA 6 2.8 150 V mA nA dB dB ADA4850-1/ADA4850-2 SPECIFICATIONS WITH +5 V SUPPLY TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted. Table 2. Parameter DYNAMIC PERFORMANCE −3 dB Bandwidth Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Harmonic Distortion (dBc) HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase Crosstalk (RTI)–ADA4850-2 DC PERFORMANCE Input Offset Voltage Input Offset Voltage Drift Input Bias Current Input Bias Current Drift Input Bias Offset Current Open-Loop Gain INPUT CHARACTERISTICS Input Resistance Input Capacitance Input Common-Mode Voltage Range Input Overdrive Recovery Time (Rise/Fall) Common-Mode Rejection Ratio POWER-DOWN Power-Down Input Voltage Turn-Off Time Turn-On Time Power-Down Bias Current/Power Down Pin Enabled Power-Down OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range 1 Quiescent Current/Amplifier Quiescent Current (Power-Down)/Amplifier Positive Power Supply Rejection Negative Power Supply Rejection 1 Conditions Min Typ Max Unit G = +1, VO = 0.1 V p-p G = +1, VO = 0.5 V p-p G = +2, VO = 1.4 V p-p, RL = 150 Ω G = +2, VO = 4 V step G = +2, VO = 2 V step G = +2, VO = 1 V step, RL = 150 Ω 175 110 9 220 160 85 MHz MHz MHz V/μs V/μs ns fC = 1 MHz, VO = 2 V p-p, G = +2, RL = 150 Ω f = 100 kHz f = 100 kHz G = +3, NTSC, RL = 150 Ω G = +3, NTSC, RL = 150 Ω f = 4.5 MHz, RL = 150 Ω, VO = 2 V p-p −81/−86 10 2.5 0.12 0.09 60 dBc nV/√Hz pA/√Hz % Degrees dB VO = 2.25 V to 2.75 V 83 0.6 4 2.3 4 30 105 −85 0.5/5.0 1.2 −0.2 to +2.8 50/40 −110 MΩ pF V ns dB Power-down ADA4850-1/ADA4850-2 Enabled ADA4850-1/ADA4850-2 <0.7/<0.6 >0.8/>1.7 0.7 50 V V μs ns Power-down = 5 V Power-down = 0 V 0.05 0.02 Differential/common-mode VIN = +5.5 V to −0.5 V, G = +1 VCM = 2.0 V VIN = +1.1 V to −0.1 V, G = +5 0.14 to 4.83 Sinking/sourcing For operation on bipolar supplies, see the Operating the ADA4850-1/ADA4850-2 on Bipolar Supplies section. Rev. B | Page 4 of 16 −84 −84 4.2 0.13 0.2 60/70 0.07 to 4.92 118/94 2.7 +VS = +5 V to +6 V, −VS = 0 V +VS = +5 V, −VS = −0 V to −1 V 4.2 2.5 15 −100 −102 mV μV/°C μA nA/°C nA dB mA μA ns V mA 6 2.9 150 V mA nA dB dB ADA4850-1/ADA4850-2 ABSOLUTE MAXIMUM RATINGS Table 3. Rating 12.6 V See Figure 4 (−VS + 6) V (−VS − 0.5 ) V to (+VS + 0.5) V +VS to −VS −65°C to +125°C −40°C to +125°C 300°C 150°C 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. THERMAL RESISTANCE θJA is specified for the worst-case conditions, that is, θJA is specified for the device soldered in the circuit board for surface-mount packages. ⎞ VOUT 2 ⎟− ⎟ RL ⎠ RMS output voltages should be considered. If RL is referenced to −VS, as in single-supply operation, the total drive power is VS × IOUT. If the rms signal levels are indeterminate, consider the worst case, when VOUT = VS/4 for RL to midsupply. PD = (VS × I S ) + (VS /4)2 RL In single-supply operation with RL referenced to −VS, the worst case is VOUT = VS/2. Airflow increases heat dissipation, effectively reducing θJA. Also, more metal directly in contact with the package leads and exposed paddle from metal traces through holes, ground, and power planes reduce θJA. Unit °C/W °C/W 2.5 Maximum Power Dissipation The maximum safe power dissipation for the ADA4850-1/ ADA4850-2 is limited by the associated rise in junction temperature (TJ) on the die. At approximately 150°C, which is the glass transition temperature, the plastic changes its properties. Even temporarily exceeding this temperature limit may change the stresses that the package exerts on the die, permanently shifting the parametric performance of the ADA4850-1/ADA4850-2. Exceeding a junction temperature of 150°C for an extended period of time can result in changes in silicon devices, potentially causing degradation or loss of functionality. 2.0 LFCSP-8 LFCSP-16 1.5 1.0 0.5 0 –55 –45 –35 –25 –15 –5 5 15 25 35 45 55 65 75 85 95 105 115 125 AMBIENT TEMPERATURE (°C) 05320-055 θJA 91 80 ⎛V V PD = (VS × I S ) + ⎜⎜ S × OUT RL ⎝ 2 Figure 4 shows the maximum safe power dissipation in the package vs. the ambient temperature for the LFCSP (91°C/W) package on a JEDEC standard 4-layer board. θJA values are approximations. Table 4. Package Type 16-Lead LFCSP 8-Lead LFCSP PD = Quiescent Power + (Total Drive Power − Load Power) MAXIMUM POWER DISSIPATION (W) Parameter Supply Voltage Power Dissipation Power Down Pin Voltage Common-Mode Input Voltage Differential Input Voltage Storage Temperature Operating Temperature Range Lead Temperature Range (Soldering 10 sec) Junction Temperature The power dissipated in the package (PD) is the sum of the quiescent power dissipation and the power dissipated in the die due to the ADA4850-1/ADA4850-2 drive at the output. The quiescent power is the voltage between the supply pins (VS) times the quiescent current (IS). Figure 4. Maximum Power Dissipation vs. Temperature for a 4-Layer Board ESD CAUTION Rev. B | Page 5 of 16 ADA4850-1/ADA4850-2 TYPICAL PERFORMANCE CHARACTERISTICS TA = 25°C, RF = 0 Ω for G = +1, RF = 1 kΩ for G > +1, RL = 1 kΩ, unless otherwise noted. 4 0 VS = 5V RL = 150Ω VOUT = 0.1V p-p –1 G = –1 2 G = +2 –2 –3 G = +10 –4 6pF G = +1 VS = 5V RL = 1kΩ VOUT = 0.1V p-p 3 CLOSED-LOOP GAIN (dB) 1 0 1pF –1 0pF –2 –3 –4 –5 –6 1 10 100 FREQUENCY (MHz) 1 05320-044 –6 Figure 5. Small Signal Frequency Response for Various Gains 100 6.2 1 RL = 150Ω –1 5.9 GAIN (dB) 6.0 RL = 1kΩ –2 VS = 5V G = +2 RL = 150Ω 6.1 0 –3 VS = 5V, VOUT = 2V p-p 5.8 VS = 5V, VOUT = 1.4V p-p VS = 3V, VOUT = 0.5V p-p 5.7 –4 VS = 5V, VOUT = 0.1V p-p 5.6 VS = 5V G = +1 VOUT = 0.1V p-p –6 1 10 100 1000 FREQUENCY (MHz) 5.4 100k 1M 10M Figure 6. Small Signal Frequency Response for Various Loads Figure 9. 0.1 dB Flatness Response 3 1 2 0 VS = 5V G = +1 VOUT = 0.5V p-p VS = 3V CLOSED-LOOP GAIN (dB) 1 0 –1 VS = 5V –2 –3 –4 G = +1 RL = 150Ω VOUT = 0.1V p-p –5 100M FREQUENCY (Hz) –1 RL = 150Ω –2 RL = 1kΩ –3 –4 –5 –6 10 100 1000 FREQUENCY (MHz) 05320-046 –7 –6 1 05320-047 5.5 05320-045 –5 CLOSED-LOOP GAIN (dB) 300 Figure 8. Small Signal Frequency Response for Various Capacitor Loads 2 CLOSED-LOOP GAIN (dB) 10 FREQUENCY (MHz) 05320-007 –5 1 10 100 1000 FREQUENCY (MHz) Figure 10. Large Frequency Response for Various Loads Figure 7. Small Signal Frequency Response for Various Supplies Rev. B | Page 6 of 16 05320-048 NORMALIZED CLOSED-LOOP GAIN (dB) 1 ADA4850-1/ADA4850-2 3 300 VS = 3V G = +1 RL = 1kΩ VOUT = 0.1V p-p G = +2 VS = 5V RL = 1kΩ 250 +85°C 0 +25°C –1 –40°C –2 200 POSITIVE SLEW RATE 150 100 –3 10 1 100 0 05320-057 –5 1000 FREQUENCY (MHz) 0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5 5.0 OUTPUT VOLTAGE STEP (V) Figure 11. Small Signal Frequency Response for Various Temperatures 05320-024 50 –4 Figure 14. Slew Rate vs. Output Voltage 10k 3 VS = 5V G = +1 RL = 1kΩ VOUT = 0.1V p-p +125°C 1 1k SUPPLY CURRENT (μA) 2 CLOSED-LOOP GAIN (dB) NEGATIVE SLEW RATE 1 SLEW RATE (V/μs) CLOSED-LOOP GAIN (dB) 2 +125°C +85°C 0 –1 +25°C –2 –40°C VS = 3V, 5V, ADA4850-2 100 VS = 3V, 5V, ADA4850-1 ENABLE 10 VS = 3V, 5V, ADA4850-1 POWER DOWN –3 1 10 1 100 0.1 05320-098 –5 1000 FREQUENCY (MHz) 0.5 0 0 –30 100 –60 –150 40 GAIN 20 –180 0 –210 CROSSTALK (dB) –120 60 OPEN-LOOP PHASE (Degrees) –90 3.0 3.5 4.0 4.5 5.0 G = +2 VS = 5V RL = 150Ω VOUT = 2V p-p –60 VOUT2 TO VOUT1 –70 –80 VOUT1 TO VOUT2 –20 10 100 1k 10k 100k 1M 10M 100M FREQUENCY (Hz) –240 1G –100 100k 1M 10M FREQUENCY (Hz) Figure 16. Crosstalk vs. Frequency Figure 13. Open-Loop Gain and Phase vs. Frequency Rev. B | Page 7 of 16 100M 05320-037 –90 05320-012 OPEN-LOOP GAIN (dB) PHASE 2.5 –40 –50 80 2.0 Figure 15. Supply Current vs. Power-Down Voltage VS = 5V 120 1.5 POWER-DOWN VOLTAGE (V) Figure 12. Small Signal Frequency Response for Various Temperatures 140 1.0 05320-036 –4 ADA4850-1/ADA4850-2 –40 2.575 G = +1 VS = 5V VOUT = 500mV p-p OUTPUT VOLTAGE (V) –60 RL = 1kΩ HD2 RL = 150Ω HD2 RL = 1kΩ HD3 –110 0.1 1 10 100 FREQUENCY (MHz) 2.425 0 OUTPUT VOLTAGE FOR 5V SUPPLY (V) VOUT = 200mV p-p HD2 –90 VOUT = 200mV p-p HD3 –100 VOUT = 500mV p-p HD3 –120 0.1 1 10 100 80 100 120 140 160 180 200 FREQUENCY (MHz) G = +2 RL = 1kΩ VS = 5V 3.00 2.75 2.50 2.25 2.00 1.75 05320-103 0 50 100 150 200 TIME (ns) Figure 18. Harmonic Distortion vs. Frequency for Various VOUT Figure 21. Large Signal Transient Response 0.65 2.875 OUTPUT VOLTAGE FOR 5V SUPPLY (V) G = +2 RL = 1kΩ VS = 5V 0.55 0.50 0.45 0.40 0.875 G = +1 RL = 1kΩ 2.750 0.750 2.625 0.625 2.500 0.500 2.375 VS = 5V 2.250 0.375 0.250 0 50 100 150 200 TIME (ns) 05320-019 VS = 3V 0.35 2.125 0 50 100 150 0.125 200 TIME (ns) Figure 22. Large Signal Transient Response for Various Supplies Figure 19. Small Signal Transient Response for Various Supplies Rev. B | Page 8 of 16 05320-049 HARMONIC DISTORTION (dBc) VOUT = 500mV p-p HD2 –110 OUTPUT VOLTAGE (V) 60 3.25 –70 0.60 40 Figure 20. Small Signal Transient Response for Capacitive Load –50 –80 20 TIME (ns) Figure 17. Harmonic Distortion vs. Frequency for Various Loads G = +2 VS = 5V –60 RL = 1kΩ 2.475 2.450 RL = 150Ω HD3 –100 2.500 05320-020 –90 2.525 05320-050 –80 0pF OUTPUT VOLTAGE FOR 3V SUPPLY (V) –70 10pF G = +1 VS = 5V RL = 150Ω 2.550 05320-102 HARMONIC DISTORTION (dBc) –50 ADA4850-1/ADA4850-2 6 VOLTAGE NOISE (nV/ Hz) 5 VDISABLE 4 VOLTAGE (V) 1000 G = +2 VS = 5V fIN = 400kHz 3 2 1 100 10 0 15 30 45 TIME (μs) 1 10 05320-025 0 100 10k 100k 1M 10M 100M FREQUENCY (Hz) Figure 23. Enable/Disable Time Figure 26. Voltage Noise vs. Frequency 5.5 100 G = +1 VS = 5V RL = 150Ω f = 1MHz 5.0 INPUT 4.5 4.0 CURRENT NOISE (pA/ Hz) INPUT AND OUTPUT VOLTAGE (V) 1k 05320-059 VOUT –1 3.5 3.0 2.5 OUTPUT 2.0 1.5 1.0 10 0.5 100 200 300 400 500 600 700 800 900 1000 TIME (ns) 1 10 05320-058 0 100 10k 100k 1M 10M 100M 1G 3 4 FREQUENCY (Hz) Figure 24. Input Overdrive Recovery Figure 27. Current Noise vs. Frequency 350 3.5 3.0 OUTPUT G = +5 VS = 3V RL = 150Ω f = 1MHz 300 2.5 VS = 5V N = 1720 x = 450μV σ = 750μV 250 COUNT 2.0 5 × INPUT 1.5 200 150 1.0 100 0.5 50 –0.5 0 100 200 300 400 500 600 700 800 TIME (ns) 900 1000 Figure 25. Output Overdrive Recovery 0 –4 –3 –2 –1 0 1 2 VOFFSET (mV) Figure 28. Input Offset Voltage Distribution Rev. B | Page 9 of 16 05320-065 0 05320-060 INPUT AND OUTPUT VOLTAGE (V) 1k 05320-095 0 –0.5 ADA4850-1/ADA4850-2 400 –1.2 +IB 380 VS = 5V –1.4 INPUT BIAS CURRENT (μA) 360 320 300 280 260 240 –1.6 VS = 5V –1.8 –IB VS = 3V –2.0 05320-092 –2.2 220 –0.5 0 0.5 1.0 1.5 2.0 2.5 3.5 3.0 –2.4 –40 05320-063 200 –1.0 VCM (V) 5 20 35 50 65 80 95 110 125 Figure 32. Input Bias Current vs. Temperature for Various Supplies 95 0.6 VS = 3V 0.5 +VSAT 0.4 0.3 –VSAT VS = 5V 0.2 0.1 5 10 15 20 25 30 35 40 45 90 50 LOAD CURRENT (mA) 80 –VS – VOUT 75 70 65 –40 –25 –10 5 20 35 50 65 80 95 110 125 TEMPERATURE (°C) Figure 30. Output Saturation Voltage vs. Load Current (Voltage Differential from Rails) Figure 33. Output Saturation Voltage vs. Temperature (Voltage Differential from Rails) 4.9 –30 4.8 VS = 3V VS = 5V SUPPLY CURRENT (mA) –34 –36 –38 –40 –42 VS = 5V 05320-091 –44 –25 –10 5 20 35 50 65 80 95 110 125 4.7 4.6 VS = 3V 4.5 4.4 4.3 4.2 –40 05320-090 –32 –46 –40 +VS – VOUT 85 05320-064 0 0 VS = 5V RL = 1kΩ OUTPUT SATURATION VOLTAGE (mV) OUTPUT SATURATION VOLTAGE (V) –10 TEMPERATURE (°C) Figure 29. Input Offset Voltage vs. Common-Mode Voltage POWER-DOWN PIN BIAS CURRENT (μA) –25 05320-062 VOS (μV) 340 –25 –10 5 20 35 50 65 80 95 110 TEMPERATURE (°C) TEMPERATURE (°C) Figure 31. Power-Down Bias Current vs. Temperature for Various Supplies Rev. B | Page 10 of 16 Figure 34. Current vs. Temperature for Various Supplies 125 ADA4850-1/ADA4850-2 –20 0 –10 –30 –20 –30 +PSR –40 –50 –60 –PSR –70 –80 –90 –40 –50 CHANNEL 1 –60 –70 CHANNEL 2 –80 –90 –100 –110 –110 100 –120 1k 1k 10k 100k 1M 10M 05320-094 –100 100M FREQUENCY (Hz) 0.7 INPUT OFFSET VOLTAGE (mV) 0.6 0.5 VS = 5V 0.4 0.3 VS = 3V 0.2 0.1 05320-093 0 –25 –10 5 20 35 50 65 80 95 110 100k 1M 10M 100M FREQUENCY (Hz) Figure 37. Common-Mode Rejection (CMR) vs. Frequency Figure 35. Power Supply Rejection (PSR) vs. Frequency –0.1 –40 10k 125 TEMPERATURE (°C) Figure 36. Input Offset Voltage vs. Temperature for Various Supplies Rev. B | Page 11 of 16 05320-034 COMMON-MODE REJECTION (dB) POWER SUPPLY REJECTION (dB) VS = 5V VS = 5V ADA4850-1/ADA4850-2 CIRCUIT DESCRIPTION The ADA4850-1/ADA4850-2 feature a high slew rate input stage that is a true single-supply topology, capable of sensing signals at or below the negative supply rail. The rail-to-rail output stage can swing to within 80 mV of either supply rail when driving light loads and within 0.17 V when driving 150 Ω. High speed performance is maintained at supply voltages as low as 2.7 V. Higher frequency signals require more headroom than the lower frequencies to maintain distortion performance. Figure 39 illustrates how the rising edge settling time for the amplifier configured as a unity-gain follower stretches out as the top of a 1 V step input approaches and exceeds the specified input common-mode voltage limit. 3.6 HEADROOM AND OVERDRIVE RECOVERY CONSIDERATIONS Exceeding the headroom limit is not a concern for any inverting gain on any supply voltage, as long as the reference voltage at the amplifier’s positive input lies within the amplifier’s input common-mode range. The input stage sets the headroom limit for signals when the amplifier is used in a gain of +1 for signals approaching the positive rail. For high speed signals, however, there are other considerations. Figure 38 shows −3 dB bandwidth vs. dc input voltage for a unity-gain follower. As the common-mode voltage approaches the positive supply, the bandwidth begins to drop when within 2 V of +VS. This can manifest itself in increased distortion or settling time. 2 VCM = 3V VCM = 3.1V VCM = 3.2V 0 VCM = 3.3V –3 –5 –6 0.1 VSTEP = 2V TO 3V VSTEP = 2.1V TO 3.1V 2.6 VSTEP = 2.2V TO 3.2V 2.4 VSTEP = 2.3V TO 3.3V VSTEP = 2.4V TO 3.4V 2.0 1.8 0 10 20 30 40 50 60 70 80 90 100 TIME (ns) Figure 39. Pulse Response, Input Headroom Limits The recovery time from input voltages 2.2 V or closer to the positive supply is approximately 50 ns, which is limited by the settling artifacts caused by transistors in the input stage coming out of saturation. The ADA4850-1/ADA4850-2 do not exhibit phase reversal, even for input voltages beyond the voltage supply rails. Going more than 0.6 V beyond the power supplies turns on protection diodes at the input stage, which greatly increase the current draw of the devices. Output For signals approaching the negative supply and inverting gain, and high positive gain configurations, the headroom limit is the output stage. The ADA4850-1/ADA4850-2 amplifiers use a common-emitter output stage. This output stage maximizes the available output range, limited by the saturation voltage of the output transistors. The saturation voltage increases with drive current, due to the output transistor collector resistance. As the saturation point of the output stage is approached, the output signal shows increasing amounts of compression and clipping. As in the input headroom case, higher frequency signals require a bit more headroom than the lower frequency signals. –2 –4 2.8 2.2 VS = 5V G = +1 RL = 1kΩ VOUT = 0.1V p-p 1 Output overload recovery is typically within 40 ns after the amplifier’s input is brought to a nonoverloading value. 10 100 FREQUENCY (MHz) 1000 05320-096 GAIN (dB) –1 3.0 05320-061 The ADA4850-1/ADA4850-2 are designed for use in low voltage systems. To obtain optimum performance, it is useful to understand the behavior of the amplifier as input and output signals approach the amplifier’s headroom limits. The input common-mode voltage range extends 200 mV below the negative supply voltage or ground for single-supply operation to within 2.2 V of the positive supply voltage. Therefore, in a gain of +3, the ADA4850-1/ADA4850-2 can provide full railto-rail output swing for supply voltage as low as 3.3 V, assuming the input signal swing is from −VS (or ground) to 1.1 V. OUTPUT VOLTAGE (V) 3.2 Input 1 VS = 5V G = +1 RL = 1kΩ 3.4 Figure 38. Unity-Gain Follower Bandwidth vs. Frequency for Various Input Common-Mode Rev. B | Page 12 of 16 ADA4850-1/ADA4850-2 Figure 40 shows the output recovery transients for the amplifier recovering from a saturated output from the top and bottom supplies to a point at midsupply. 6.5 4.5 3.5 INPUT 2.5 VOLTAGE EDGES 1.5 0.5 VOUT = –2.5V TO 0V –0.5 –1.5 0 10 The ADA4850-1/ADA4850-2 can operate on bipolar supplies up to ±5 V. The only restriction is that the voltage between −VS and the POWER DOWN pin must not exceed 6 V. Voltage differences greater than 6 V can cause permanent damage to the amplifier. For example, when operating on ±5 V supplies, the POWER DOWN pin must not exceed +1 V. POWER-DOWN PINS 20 30 40 50 60 70 TIME (ns) 80 90 100 05320-042 INPUT AND OUTPUT VOLTAGE (V) VS = 5V G = –1 RL = 1kΩ VOUT = +2.5V TO 0V 5.5 OPERATING THE ADA4850-1/ADA4850-2 ON BIPOLAR SUPPLIES The ADA4850-1/ADA4850-2 feature an ultralow power-down mode that lowers the supply current to less than 150 nA. When a power-down pin is brought to within 0.6 V of the negative supply, the amplifier is powered down. Table 5 outlines the power-down pins functionality. To ensure proper operation, the power-down pins (PD1, PD2) should not be left floating. Table 5. Power-Down Pins Functionality Figure 40. Overload Recovery Supply Voltage Power Down Enabled Rev. B | Page 13 of 16 3 V and 5 V ADA4850-1 0 V to 0.7 V 0.8 to +VS ADA4850-2 0 V to 0.6 V 1.7 V to +VS ADA4850-1/ADA4850-2 OUTLINE DIMENSIONS 3.25 3.00 SQ 2.75 0.60 MAX 5 2.95 2.75 SQ 2.55 TOP VIEW PIN 1 INDICATOR 8 12° MAX 1.60 1.45 1.30 EXPOSED PAD (BOTTOM VIEW) 4 1 0.50 0.40 0.30 0.70 MAX 0.65 TYP 0.90 MAX 0.85 NOM 0.50 BSC 0.60 MAX 1.89 1.74 1.59 PIN 1 INDICATOR 0.05 MAX 0.01 NOM 0.20 REF 061507-B 0.30 0.23 0.18 SEATING PLANE Figure 41. 8-Lead Lead Frame Chip Scale Package [LFCSP_VD] 3 mm × 3 mm Body, Very Thin, Dual Lead (CP-8-2) Dimensions shown in millimeters 3.00 BSC SQ 0.60 MAX 13 12 0.45 PIN 1 INDICATOR TOP VIEW 2.75 BSC SQ 0.80 MAX 0.65 TYP 12° MAX SEATING PLANE 16 1 PIN 1 INDICATOR *1.65 1.50 SQ 1.35 EXPOSED PAD 0.50 BSC 0.90 0.85 0.80 0.50 0.40 0.30 9 (BOTTOM VIEW) 4 8 5 0.25 MIN 1.50 REF 0.05 MAX 0.02 NOM 0.30 0.23 0.18 0.20 REF *COMPLIANT TO JEDEC STANDARDS MO-220-VEED-2 EXCEPT FOR EXPOSED PAD DIMENSION. Figure 42. 16-Lead Lead Frame Chip Scale Package [LFCSP_VQ] 3 mm × 3 mm Body, Very Thin Quad (CP-16-3) Dimensions shown in millimeters ORDERING GUIDE Model ADA4850-1YCPZ-R2 1 ADA4850-1YCPZ-RL1 ADA4850-1YCPZ-RL71 ADA4850-2YCPZ-R21 ADA4850-2YCPZ-RL1 ADA4850-2YCPZ-RL71 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 Package Description 8-Lead Lead Frame Chip Scale Package (LFCSP_VD) 8-Lead Lead Frame Chip Scale Package (LFCSP_VD) 8-Lead Lead Frame Chip Scale Package (LFCSP_VD) 16-Lead Lead Frame Chip Scale Package (LFCSP_VQ) 16-Lead Lead Frame Chip Scale Package (LFCSP_VQ) 16-Lead Lead Frame Chip Scale Package (LFCSP_VQ) Z = RoHS Compliant Part. Rev. B | Page 14 of 16 Package Option CP-8-2 CP-8-2 CP-8-2 CP-16-3 CP-16-3 CP-16-3 Branding HWB HWB HWB HTB HTB HTB ADA4850-1/ADA4850-2 NOTES Rev. B | Page 15 of 16 ADA4850-1/ADA4850-2 NOTES ©2005–2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05320-0-12/07(B) Rev. B | Page 16 of 16