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Low Cost, High Speed, Rail-to-Rail, Output Op Amps ADA4851-1/ADA4851-2/ADA4851-4
FEATURES
High speed 130 MHz, -3 dB bandwidth 375 V/s slew rate 55 ns settling time to 0.1% Excellent video specifications 0.1 dB flatness: 11 MHz Differential gain: 0.08% Differential phase: 0.09 Fully specified at +3 V, +5 V, and 5 V supplies Rail-to-rail output Output swings to within 60 mV of either rail Low voltage offset: 0.6 mV Wide supply range: 3 V to 10 V Low power: 2.5 mA/amplifier Power-down mode Available in space-saving packages 6-lead SOT-23, 8-lead MSOP, and 14-lead TSSOP
PIN CONFIGURATIONS
VOUT 1 -VS 2 +IN 3
ADA4851-1
6 5 4
+VS POWER DOWN
05143-001
-IN
TOP VIEW (Not to Scale)
Figure 1. ADA4851-1, 6-Lead SOT-23 (RJ-6)
ADA4851-2
OUT1 1 -IN1 2 +IN1 3 -VS 4 TOP VIEW (Not to Scale)
8 7 6 5
+VS OUT -IN2 +IN2
05143-058
Figure 2. ADA4851-2, 8-Lead MSOP (RM-8)
VOUT 1 1 -IN 1 2 +IN 1
3 14 13 12 11 10 9 8
VOUT 4 -IN 4 +IN 4 -VS +IN 3 -IN 3 VOUT 3
05143-054
APPLICATIONS
Consumer video Professional video Video switchers Active filters Clock buffers
+VS 4 +IN 2 5 -IN 2 6 VOUT 2 7
TOP VIEW (Not to Scale)
ADA4851-4
Figure 3. ADA4851-4, 14-Lead TSSOP (RU-14)
GENERAL DESCRIPTION
The ADA4851-1 (single)/ADA4851-2 (dual)/ADA4851-4 (quad) are low cost, high speed, voltage feedback rail-to-rail output op amps. Despite their low price, these parts provide excellent overall performance and versatility. The 130 MHz, -3 dB bandwidth and high slew rate make these amplifiers well suited for many general-purpose, high speed applications. The ADA4851 family is designed to operate at supply voltages as low as +3 V and up to 5 V. These parts provide true singlesupply capability, allowing input signals to extend 200 mV below the negative rail and to within 2.2 V of the positive rail. On the output, the amplifiers can swing within 60 mV of either supply rail. With their combination of low price, excellent differential gain (0.08%), differential phase (0.09), and 0.1 dB flatness out to 11 MHz, these amplifiers are ideal for consumer video applications. The ADA4851 family is designed to work over the extended temperature range (-40C to +125C).
4 3 2
CLOSED-LOOP GAIN (dB)
G = +1 VS = 5V RL = 1k CL = 5pF
1 0 -1 -2 -3 -4 -5 1 10 100 1k
05143-004
-6
FREQUENCY (MHz)
Figure 4. Small Signal Frequency Response
Rev. E
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.
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ADA4851-1/ADA4851-2/ADA4851-4 TABLE OF CONTENTS
Features .............................................................................................. 1 Applications....................................................................................... 1 Pin Configurations ........................................................................... 1 General Description ......................................................................... 1 Revision History ............................................................................... 2 Specifications..................................................................................... 3 Specifications with +3 V Supply................................................. 3 Specifications with +5 V Supply................................................. 4 Specifications with 5 V Supply................................................. 5 Absolute Maximum Ratings............................................................ 6 Thermal Resistance .......................................................................6 ESD Caution...................................................................................6 Typical Performance Characteristics ..............................................7 Circuit Description......................................................................... 13 Headroom Considerations........................................................ 13 Overload Behavior and Recovery ............................................ 14 Single-Supply Video Amplifier................................................. 15 Video Reconstruction Filter...................................................... 15 Outline Dimensions ....................................................................... 16 Ordering Guide .......................................................................... 17
REVISION HISTORY
8/07--Rev. D to Rev. E Changes to Applications .................................................................. 1 Changes to Common-Mode Rejection Ratio, Conditions.......... 5 Changes to Headroom Considerations Section ......................... 13 4/06--Rev. C to Rev. D Added Video Reconstruction Filter Section ............................... 15 5/05--Rev. B to Rev. C Changes to General Description .................................................... 1 Changes to Input Section............................................................... 14 4/05--Rev. A to Rev. B Added ADA4851-2.............................................................Universal Added 8-Lead MSOP .........................................................Universal Changes to Features.......................................................................... 1 Changes to General Description .................................................... 1 Changes to Table 1............................................................................ 3 Changes to Table 2............................................................................ 4 Changes to Table 3............................................................................ 5 Changes to Table 4 and Figure 5..................................................... 6 Changes to Figure 12, Figure 15, and Figure 17 ........................... 8 Changes to Figure 18........................................................................ 9 Changes to Figure 28 Caption....................................................... 10 Changes to Figure 33...................................................................... 11 Changes to Figure 36 and Figure 38............................................. 12 Added Figure 39.............................................................................. 12 Changes to Circuit Description Section ...................................... 13 Changes to Headroom Considerations Section ......................... 13 Changes to Overload Behavior and Recovery Section .............. 14 Added Single-Supply Video Amplifier Section .......................... 15 Updated Outline Dimensions ....................................................... 16 Changes to Ordering Guide .......................................................... 17 1/05--Rev. 0 to Rev. A Added ADA4851-4.............................................................Universal Added 14-Lead TSSOP ......................................................Universal Changes to Features ..........................................................................1 Changes to General Description .....................................................1 Changes to Figure 3...........................................................................1 Changes to Specifications.................................................................3 Changes to Figure 4...........................................................................6 Changes to Figure 8...........................................................................7 Changes to Figure 11.........................................................................8 Changes to Figure 22.........................................................................9 Changes to Figure 23, Figure 24, and Figure 25 ......................... 10 Changes to Figure 27 and Figure 28............................................. 10 Changes to Figure 29, Figure 30, and Figure 31 ......................... 11 Changes to Figure 34...................................................................... 11 Added Figure 37 ............................................................................. 12 Changes to Ordering Guide .......................................................... 15 Updated Outline Dimensions....................................................... 15 10/04--Revision 0: Initial Version
Rev. E | Page 2 of 20
ADA4851-1/ADA4851-2/ADA4851-4 SPECIFICATIONS
SPECIFICATIONS WITH +3 V SUPPLY
TA = 25C, RF = 0 for G = +1, RF = 1 k for G > +1, RL = 1 k, unless otherwise noted. Table 1.
Parameter DYNAMIC PERFORMANCE -3 dB Bandwidth Conditions G = +1, VO = 0.1 V p-p G = +1, VO = 0.5 V p-p G = +2, VO = 1 V p-p, RL = 150 G = +2, VO = 1 V p-p, RL = 150 G = +2, VO = 1 V step G = +2, VO = 1 V step, RL = 150 fC = 1 MHz, VO = 1 V p-p, G = -1 f = 100 kHz f = 100 kHz G = +3, NTSC, RL = 150 , VO = 2 V p-p G = +3, NTSC, RL = 150 , VO = 2 V p-p f = 5 MHz, G = +2, VO = 1.0 V p-p Min 104 80 Typ 130 105 40 15 100 50 -73/-79 10 2.5 0.44 0.41 -70/-60 0.6 4 2.3 6 20 105 0.5/5.0 1.2 -0.2 to +0.8 60/60 -103 <1.1 >1.6 0.7 60 4 -14 70/100 0.03 to 2.94 90/70 12 2.7 0.3 6 -20 3.3 4.0 Max Unit MHz MHz MHz MHz V/s ns dBc nV/Hz pA/Hz % Degrees dB mV V/C A nA/C nA dB M pF V ns dB V V s ns A A ns V mA V mA mA dB dB
Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Harmonic Distortion, HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase Crosstalk (RTI)--ADA4851-2/ADA4851-4 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 Enabled Power-Down OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range Quiescent Current per Amplifier Quiescent Current (Power-Down) Positive Power Supply Rejection Negative Power Supply Rejection
VO = 0.25 V to 0.75 V Differential/common-mode
80
VIN = +3.5 V, -0.5 V, G = +1 VCM = 0 V to 0.5 V Power-down Enabled
-81
Power-down = 3 V Power-down = 0 V VIN = +0.7 V, -0.1 V, G = +5 0.05 to 2.91 Sinking/sourcing 2.7 Power-down = low +VS = +2.5 V to +3.5 V, -VS = -0.5 V +VS = +2.5 V, -VS = -0.5 V to -1.5 V
-81 -80
2.4 0.2 -100 -100
Rev. E | Page 3 of 20
ADA4851-1/ADA4851-2/ADA4851-4
SPECIFICATIONS WITH +5 V SUPPLY
TA = 25C, RF = 0 for G = +1, RF = 1 k for G > +1, RL = 1 k, unless otherwise noted. Table 2.
Parameter DYNAMIC PERFORMANCE -3 dB Bandwidth Conditions 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 G = +2, VO = 1.4 V p-p, RL = 150 G = +2, VO = 2 V step G = +2, VO = 2 V step, RL = 150 fC = 1 MHz, VO = 2 V p-p, G = +1 f = 100 kHz f = 100 kHz G = +2, NTSC, RL = 150 , VO = 2 V p-p G = +2, NTSC, RL = 150 , VO = 2 V p-p f = 5 MHz, G = +2, VO = 2.0 V p-p Min 96 72 Typ 125 96 35 11 200 55 -80/-100 10 2.5 0.08 0.11 -70/-60 0.6 4 2.2 6 20 107 0.5/5.0 1.2 -0.2 to +2.8 50/45 -105 <1.1 >1.6 0.7 50 33 -22 60/70 0.06 to 4.94 110/90 12 2.8 0.3 40 -30 3.4 3.9 Max Unit MHz MHz MHz MHz V/s ns dBc nV/Hz pA/Hz % Degrees dB mV V/C A nA/C nA dB M pF V ns dB V V s ns A A ns V mA V mA mA dB dB
Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Harmonic Distortion, HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase Crosstalk (RTI)--ADA4851-2/ADA4851-4 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 Enabled Power-Down OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range Quiescent Current per Amplifier Quiescent Current (Power-Down) Positive Power Supply Rejection Negative Power Supply Rejection
VO = 1 V to 4 V Differential/common-mode
97
VIN = +5.5 V, -0.5 V, G = +1 VCM = 0 V to 2 V Power-down Enabled
-86
Power-down = 5 V Power-down = 0 V VIN = +1.1 V, -0.1 V, G = +5 0.09 to 4.91 Sinking/sourcing 2.7 Power-down = low +VS = +5 V to +6 V, -VS = 0 V +VS = +5 V, -VS = -0 V to -1 V
-82 -81
2.5 0.2 -101 -101
Rev. E | Page 4 of 20
ADA4851-1/ADA4851-2/ADA4851-4
SPECIFICATIONS WITH 5 V SUPPLY
TA = 25C, RF = 0 for G = +1, RF = 1 k for G > +1, RL = 1 k, unless otherwise noted. Table 3.
Parameter DYNAMIC PERFORMANCE -3 dB Bandwidth Conditions G = +1, VO = 0.1 V p-p G = +1, VO = 1 V p-p G = +2, VO = 2 V p-p, RL = 150 G = +2, VO = 2 V p-p, RL = 150 G = +2, VO = 7 V step G = +2, VO = 2 V step G = +2, VO = 2 V step, RL = 150 fC = 1 MHz, VO = 2 V p-p, G = +1 f = 100 kHz f = 100 kHz G = +2, NTSC, RL = 150 , VO = 2 V p-p G = +2, NTSC, RL = 150 , VO = 2 V p-p f = 5 MHz, G = +2, VO = 2.0 V p-p Min 83 52 Typ 105 74 40 11 375 190 55 -83/-107 10 2.5 0.08 0.09 -70/-60 0.6 4 2.2 6 20 106 0.5/5.0 1.2 -5.2 to +2.8 50/25 -105 < -3.9 > -3.4 0.7 30 100 -50 80/50 -4.92 to +4.92 125/110 12 3.2 0.3 130 -60 3.5 4.0 Max Unit MHz MHz MHz MHz V/s V/s ns dBc nV/Hz pA/Hz % Degrees dB mV V/C A nA/C nA dB M pF V ns dB V V s ns A A ns V mA V mA mA dB dB
Bandwidth for 0.1 dB Flatness Slew Rate Settling Time to 0.1% NOISE/DISTORTION PERFORMANCE Harmonic Distortion, HD2/HD3 Input Voltage Noise Input Current Noise Differential Gain Differential Phase Crosstalk (RTI)--ADA4851-2/ADA4851-4 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 Enabled Power-Down OUTPUT CHARACTERISTICS Output Overdrive Recovery Time (Rise/Fall) Output Voltage Swing Short-Circuit Current POWER SUPPLY Operating Range Quiescent Current per Amplifier Quiescent Current (Power-Down) Positive Power Supply Rejection Negative Power Supply Rejection
VO = 2.5 V Differential/common-mode
99
VIN = 6 V, G = +1 VCM = 0 V to -4 V Power-down Enabled
-90
Power-down = +5 V Power-down = -5 V VIN = 1.2 V, G = +5 -4.87 to +4.88 Sinking/sourcing 2.7 Power-down = low +VS = +5 V to +6 V, -VS = -5 V +VS = +5 V, -VS = -5 V to -6 V
-82 -81
2.9 0.2 -101 -102
Rev. E | Page 5 of 20
ADA4851-1/ADA4851-2/ADA4851-4 ABSOLUTE MAXIMUM RATINGS
Table 4.
Parameter Supply Voltage Power Dissipation Common-Mode Input Voltage Differential Input Voltage Storage Temperature Range Operating Temperature Range Lead Temperature Junction Temperature Rating 12.6 V See Figure 5 -VS - 0.5 V to +VS + 0.5 V +VS to -VS -65C to +125C -40C to +125C JEDEC J-STD-20 150C
PD = Quiescent Power + (Total Drive Power - Load Power)
V V V 2 PD = (VS x I S ) + S x OUT - OUT RL RL 2
RMS output voltages should be considered. If RL is referenced to -VS, as in single-supply operation, the total drive power is VS x IOUT. If the rms signal levels are indeterminate, consider the worst case, when VOUT = VS/4 for RL to midsupply.
PD = (VS x I S ) +
(VS / 4 )2
RL
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.
In single-supply operation with RL referenced to -VS, worst case is VOUT = VS/2. Airflow increases heat dissipation, effectively reducing JA. In addition, more metal directly in contact with the package leads and through holes under the device reduces JA. Figure 5 shows the maximum safe power dissipation in the package vs. the ambient temperature for the 6-lead SOT-23 (170C/W), the 8-lead MSOP (150C/W), and the 14-lead TSSOP (120C/W) on a JEDEC standard 4-layer board. JA values are approximations.
2.0
THERMAL RESISTANCE
JA is specified for the worst-case conditions, that is, JA is specified for device soldered in circuit board for surface-mount packages. Table 5. Thermal Resistance
MAXIMUM POWER DISSIPATION (W)
Package Type 6-lead SOT-23 8-lead MSOP 14-lead TSSOP
JA 170 150 120
Unit C/W C/W C/W
TSSOP 1.5 MSOP 1.0
Maximum Power Dissipation
The maximum safe power dissipation for the ADA4851-1/ ADA4851-2/ADA4851-4 is limited by the associated rise in junction temperature (TJ) on the die. At approximately 150C, 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 amplifiers. Exceeding a junction temperature of 150C for an extended period can result in changes in silicon devices, potentially causing degradation or loss of functionality. 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 drive of the amplifier at the output. The quiescent power is the voltage between the supply pins (VS) times the quiescent current (IS).
SOT-23-6 0.5
-55 -45 -35 -25 -15 -5
5
15 25 35 45 55 65 75 85 95 105 115 125
AMBIENT TEMPERATURE (C)
Figure 5. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
ESD CAUTION
Rev. E | Page 6 of 20
05143-057
0
ADA4851-1/ADA4851-2/ADA4851-4 TYPICAL PERFORMANCE CHARACTERISTICS
TA = 25C, RF = 0 for G = +1, RF = 1 k for G > +1, RL = 1 k, unless otherwise noted.
1 0
CLOSED-LOOP GAIN (dB)
VS = 5V RL = 150 VOUT = 0.1V p-p
4 3 2 G = +1 VS = 5V RL = 1k VOUT = 0.1V p-p
10pF
CLOSED-LOOP GAIN (dB)
-1 -2 -3 G = +10 -4 -5 -6 -7 1 10 FREQUENCY (MHz) G = +2
G = -1
1 0 -1 -2 -3 -4 -5 5pF 0pF
05143-006
100
1
10 FREQUENCY (MHz)
100
300
Figure 6. Small Signal Frequency Response for Various Gains
1 RL = 150 0
CLOSED-LOOP GAIN (dB)
Figure 9. Small Signal Frequency Response for Various Capacitor Loads
1 +125C 0 +85C VS = 5V G = +1 VOUT = 0.1V p-p -40C +25C
-1 -2 -3 -4 -5 -6
CLOSED-LOOP GAIN (dB)
VS = 5V G = +1 VOUT = 0.1V p-p
RL = 1k
-1 -2 -3 -4 -5 -6
05143-009
1
10 FREQUENCY (MHz)
100
300
1
10 FREQUENCY (MHz)
100
300
Figure 7. Small Signal Frequency Response for Various Loads
2 1
Figure 10. Small Signal Frequency Response for Various Temperatures
1
G = +1 RL = 150 VOUT = 0.1V p-p
VS = +5V
0
VS = 5V RL = 150 VOUT = 1V p-p
CLOSED-LOOP GAIN (dB)
CLOSED-LOOP GAIN (dB)
0 -1 -2 -3 -4 -5 -6 VS = 5V
-1 -2 -3 -4 -5 -6 -7 1 10 FREQUENCY (MHz) 100 G = +10 G = +2
G = -1
1
10 FREQUENCY (MHz)
100
300
Figure 8. Small Signal Frequency Response for Various Supplies
Figure 11. Large Signal Frequency Response for Various Gains
Rev. E | Page 7 of 20
05143-012
05143-007
05143-008
05143-010
-6
ADA4851-1/ADA4851-2/ADA4851-4
6.2 6.1 VS = 5V G = +2 RL = 150 RF = 1k
DISTORTION (dBc)
-40 -50 -60 G = -1 VS = 3V RL = 150 VOUT = 2V HD2
CLOSED-LOOP GAIN (dB)
6.0 5.9 5.8 5.7 5.6 5.5 5.4 0.1 VOUT = 100mV p-p VOUT = 1V p-p VOUT = 2V p-p
-70 -80 HD3 -90 -100 -110 0.1
05143-021
1
10 FREQUENCY (MHz)
100
1 FREQUENCY (MHz)
10
Figure 12. 0.1 dB Flatness Response
1 0 VS = 5V G = +1 VOUT = 1V p-p -50 -60
Figure 15. Harmonic Distortion vs. Frequency
HARMONIC DISTORTION (dBc)
G = +2 VS = 5V RL = 1k f = 2MHz
CLOSED-LOOP GAIN (dB)
HD2
-1 -2 RL = 150 -3 -4 -5 -6 RL = 1k
-70 -80 -90 -100 -110 -120
HD3
1
10 FREQUENCY (MHz)
100
300
05143-015
0
1
2
3
4
5
6
7
8
9
10
OUTPUT AMPLITUDE (V p-p)
Figure 13. Large Frequency Response for Various Loads
140 VS = 5V 120 100 80 60 40 GAIN 20 0 -20 10 -180 -210 -240 1G PHASE -30 0
Figure 16. Harmonic Distortion vs. Output Voltage
-40 -50
OPEN-LOOP PHASE (Degrees)
G = +1 VOUT = 2V p-p VS = 5V
OPEN-LOOP GAIN (dB)
-60 -90 -120 -150
HARMONIC DISTORTION (dBc)
-60 RL = 1k HD2 -70 -80 -90 -100 -110 0.1 RL = 150 HD2 RL = 150 HD3 RL = 1k HD3
1 FREQUENCY (MHz)
10
FREQUENCY (Hz)
Figure 14. Open-Loop Gain and Phase vs. Frequency
Figure 17. Harmonic Distortion vs. Frequency for Various Loads
Rev. E | Page 8 of 20
05143-016
100
1k
10k
100k
1M
10M
100M
05143-029
05143-017
05143-014
ADA4851-1/ADA4851-2/ADA4851-4
-40
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
0.075
-50
0.050
2.550
-60 RL = 1k HD2 -70 -80 -90 -100 -110 0.1
0.025
2.525
0
2.500
RL = 150 HD2
RL = 150 HD3
-0.025 VS = +5V -0.050
VS = 5V
2.475
2.450
RL = 1k HD3 1 FREQUENCY (MHz) 10
05143-013
0
50
100 TIME (ns)
150
Figure 18. Harmonic Distortion vs. Frequency for Various Loads
6 5 OUTPUT 5 x INPUT
Figure 21. Small Signal Transient Response for Various Supplies
2.575 G = +1 VS = 5V RL = 150
INPUT AND OUTPUT VOLTAGE (V)
4 3 2 1 0 -1 -2 -3 -4 -5 0 100 200 300 400 500 600 700
G = +5 VS = 5V RL = 150 f = 1MHz
10pF 0pF
2.550
OUTPUT VOLTAGE (V)
2.525
2.500
2.475
2.450
800
900
1k
05143-019
0
20
40
60
80
100
120
140
160
180
200
TIME (ns)
TIME (ns)
Figure 19. Output Overdrive Recovery
6 5 INPUT
Figure 22. Small Signal Transient Response for Capacitive Load
1.5 3.0
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
INPUT AND OUTPUT VOLTAGE (V)
4 3 2 1 0 -1 -2 -3 -4 -5 OUTPUT
1.0 VS = 5V 0.5 VS = +5V
2.5
2.0
0
1.5
-0.5
1.0
-1.0
0.5
05143-022
0
100
200
300
400
500
600
700
800
900
1k
0
50
100 TIME (ns)
150
TIME (ns)
Figure 20. Input Overdrive Recovery
Figure 23. Large Signal Transient Response for Various Supplies
Rev. E | Page 9 of 20
05143-028
-6
-1.5
0 200
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
G = +1 VS = 5V RL = 150 f = 1MHz
G = +2 RL = 150
05143-026
-6
2.425
05143-024
-0.075
2.425 200
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
G = +1 VOUT = 2V p-p VS = 5V
G = +1 OR +2 RL = 1k
2.575
HARMONIC DISTORTION (dBc)
ADA4851-1/ADA4851-2/ADA4851-4
1.5 3.0
6
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
OUTPUT VOLTAGE FOR 5V SUPPLY (V)
G = +1 RL = 150 1.0 VS = 5V 0.5 VS = +5V 2.0 2.5
5 4
VOLTAGE (V)
G = +2 VS = 5V fIN = 400kHz VDISABLE
3 2 1 0 VOUT 0 15 TIME (s) 30 45
05143-033
0
1.5
-0.5
1.0
-1.0
0.5
0
50
100 TIME (ns)
150
05143-027
-1.5
0 200
-1
Figure 24. Large Signal Transient Response for Various Supplies
0.5
Figure 27. Enable/Disable Time
3.5 3.0 VS = 5V
SUPPLY CURRENT (mA)
DC VOLTAGE DIFFERENTIAL FROM VS (V)
0.4
+VS - VOUT VS = 5V
VS = +3V 0.3
2.5 2.0 1.5 1.0 0.5
VS = +5V
VS = +3V
0.2
-VS - VOUT
0.1
0
5
10
15
20
25
30
35
05143-049
-4
-3
-2
-1
0
1
2
3
4
5
LOAD CURRENT (mA)
DISABLE VOLTAGE (V)
Figure 25. Output Saturation Voltage vs. Load Current
600
Figure 28. ADA4851-1, Supply Current vs. POWER DOWN Pin Voltage
300 200
500
INPUT OFFSET VOLTAGE (V)
G = +2 VS = 5V RL = 1k 25% TO 75% OF VO NEGATIVE SLEW RATE
SLEW RATE (V/s)
400
100 VS = 5V 0 -100 -200 -300 -400 -40 VS = +5V
VS = +3V
300 POSITIVE SLEW RATE 200
100
-25
-10
5
20
35
50
65
80
95
110
125
OUTPUT VOLTAGE STEP (V p-p)
TEMPERATURE (C)
Figure 26. Slew Rate vs. Output Voltage
Figure 29. Input Offset Voltage vs. Temperature for Various Supplies
Rev. E | Page 10 of 20
05143-035
0
1
2
3
4
5
6
7
8
9
10
05143-032
0
05143-034
0
0 -5
ADA4851-1/ADA4851-2/ADA4851-4
2.2
1000 G = +1
2.0
INPUT BIAS CURRENT (A)
VOLTAGE NOISE (nV/ Hz)
1.8 IB+, VS = +5V 1.6
IB+, VS = 5V IB-, VS = 5V
100
IB-, VS = +5V 1.4
10
100
1k
10k
100k
1M
10M
100M
TEMPERATURE (C)
FREQUENCY (Hz)
Figure 30. Input Bias Current vs. Temperature for Various Supplies
0.09 100 VS = 5V 0.08 +VS - VOUT 0.07 +VS - VOUT 0.06 -VS - VOUT VS = +5V
Figure 33. Voltage Noise vs. Frequency
DC VOLTAGE DIFFERENTIAL FROM VS (V)
G = +2
CURRENT NOISE (pA/ Hz)
10
0.05 -VS - VOUT 0.04 -40 1
05143-037
-25
-10
5
20
35
50
65
80
95
110
125
10
100
1k
10k
100k
1M
10M
100M
TEMPERATURE (C)
FREQUENCY (Hz)
Figure 31. Output Saturation vs. Temperature for Various Supplies
3.2 VS = 5V 3.0
80 70 60
Figure 34. Current Noise vs. Frequency
VS = 5V N = 420 x = -260V = 780V
SUPPLY CURRENT (mA)
2.8 VS = +5V
50
2.6
COUNT
40 30
2.4 VS = +3V 2.2
20 10 0
05143-038
-25
-10
5
20
35
50
65
80
95
110
125
-4
-3
-2
-1
0
1
2
3
4
TEMPERATURE (C)
VOFFSET (mV)
Figure 32. Supply Current vs. Temperature for Various Supplies
Figure 35. Input Offset Voltage Distribution
Rev. E | Page 11 of 20
05143-047
2.0 -40
05143-045
05143-044
-25
-10
5
20
35
50
65
80
95
110
125
05143-036
1.2 -40
1 10
ADA4851-1/ADA4851-2/ADA4851-4
-30 -40
COMMON-MODE REJECTION (dB)
0 VS = 5V -10 -20 -30
CROSSTALK (dB)
-50 -60 -70 -80 -90 -100 -110
05143-020
G = +2 VS = 5V RL = 1k VIN = 1V p-p DRIVE AMPS 1, 2, AND 4 LISTEN AMP 3
-40 -50 -60 -70 -80 -90 DRIVE AMP 1 LISTEN AMP 2
1k
10k
100k
1M
10M
100M
1G
1
10 FREQUENCY (MHz)
100
FREQUENCY (Hz)
Figure 36. Common-Mode Rejection Ratio (CMRR) vs. Frequency
0 -10 VS = 5V
Figure 38. ADA4851-4, RTI Crosstalk vs. Frequency
0 -10 -20 G = +2 VS = 5V RL = 1k VIN = 1V p-p
POWER SUPPLY REJECTION (dB)
-20 -30 -40 -50 -60 -70 -80 -90 -100 1k 10k 100k 1M 10M 100M 1G
05143-023
CROSSTALK (dB)
-30 -40 -50 -60 -70 -80 -90 1 10 FREQUENCY (MHz) 100
05143-060
+PSR -PSR
DRIVE AMP 1 LISTEN AMP 2
DRIVE AMP 2 LISTEN AMP 1
-110 100
-100 0.1
FREQUENCY (Hz)
Figure 37. Power Supply Rejection (PSR) vs. Frequency
Figure 39. ADA4851-2, RTI Crosstalk vs. Frequency
Rev. E | Page 12 of 20
05143-055
-120
-100 0.1
ADA4851-1/ADA4851-2/ADA4851-4 CIRCUIT DESCRIPTION
The ADA4851-1/ADA4851-2/ADA4851-4 feature a high slew rate input stage that is a true single-supply topology, capable of sensing signals at or below the minus supply rail. The rail-to-rail output stage can pull within 60 mV of either supply rail when driving light loads and within 0.17 V when driving 150 . High speed performance is maintained at supply voltages as low as 2.7 V.
440 460 480 500
VOS (V)
HEADROOM CONSIDERATIONS
These amplifiers are designed for use in low voltage systems. To obtain optimum performance, it is useful to understand the behavior of the amplifiers as input and output signals approach the headroom limits of the amplifiers. The input common-mode voltage range of the amplifiers extends from the negative supply voltage (actually 200 mV below this), or from ground for singlesupply operation, to within 2.2 V of the positive supply voltage. Therefore, at a gain of 3, the amplifiers can provide full rail-torail output swing for supply voltages as low as 3.3 V and down to 3 V for a gain of 4. Exceeding the headroom limit is not a concern for any inverting gain on any supply voltage, as long as the reference voltage at the positive input of the amplifier lies within the input commonmode range of the amplifier. The input stage is the headroom limit for signals approaching the positive rail. Figure 40 shows a typical offset voltage vs. the input common-mode voltage for the ADA4851-1/ADA4851-2/ ADA4851-4 amplifiers on a 5 V supply. Accurate dc performance is maintained from approximately 200 mV below the negative supply to within 2.2 V of the positive supply. For high speed signals, however, there are other considerations. Figure 41 shows -3 dB bandwidth vs. input common-mode voltage for a unity-gain follower. As the common-mode voltage gets within 2 V of positive supply, the amplifier responds well but the bandwidth begins to drop as the common-mode voltage approaches the positive supply. This can manifest itself in increased distortion or settling time. Higher frequency signals require more headroom than the lower frequencies to maintain distortion performance.
520 540 560 580 600
-6
-5
-4
-3
-2
-1 VCM (V)
0
1
2
3
4
Figure 40. VOS vs. Common-Mode Voltage, VS = 5 V
2 1 0 -1
GAIN (dB)
G = +1 RL = 1k VS = 5V
VCM = 3.0V VCM = 3.1V
-2 -3 -4 -5 -6 0.1
VCM = 3.2V VCM = 3.3V
1
10 FREQUENCY (MHz)
100
1000
Figure 41. Unity-Gain Follower Bandwidth vs. Input Common-Mode
Rev. E | Page 13 of 20
05143-050
05143-046
ADA4851-1/ADA4851-2/ADA4851-4
Figure 42 illustrates how the rising edge settling time for the amplifier is configured as a unity-gain follower, stretching out as the top of a 1 V step input that approaches and exceeds the specified input common-mode voltage limit. For signals approaching the negative supply and inverting gain and high positive gain configurations, the headroom limit is the output stage. The ADA4851-1/ADA4851-2/ADA4851-4 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 the drive current that the output transistor is required to supply due to the collector resistance of the output transistor.
3.6 3.4 3.2
OUTPUT VOLTAGE (V)
The amplifiers 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 increases the current draw of the devices.
3.50 G = +1 RL = 1k VS = 5V VSTEP = 2.25V TO 3.25V VSTEP = 2.25V TO 3.5V, 4V, AND 5V
3.25
OUTPUT VOLTAGE (V)
3.00
2.75
2.50
G = +1 RL = 1k VS = 5V
2.25
0
100
200
300
400
500
600
700
800
900
1k
2.8 2.6 2.4 2.2 2.0 1.8 0 10 20
VSTEP = 2V TO 3V VSTEP = 2.1V TO 3.1V VSTEP = 2.2V TO 3.2V VSTEP = 2.3V TO 3.3V VSTEP = 2.4V TO 3.4V
TIME (ns)
Figure 43. Pulse Response of G = +1 Follower, Input Step Overloading the Input Stage
Output
Output overload recovery is typically within 35 ns after the input of the amplifier is brought to a nonoverloading value. Figure 44 shows output recovery transients for the amplifier configured in an inverting gain of 1 recovering from a saturated output from the top and bottom supplies to a point at midsupply.
7 6
INPUT AND OUTPUT VOLTAGE (V)
30
40
50 TIME (ns)
60
70
80
90
100
Figure 42. Output Rising Edge for 1 V Step at Input Headroom Limits
05143-052
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. Figure 16 illustrates this point by plotting the typical distortion vs. the output amplitude.
VOUT = 5V TO 2.5V
G = -1 RL = 1k VS = 5V
5 4 3 2 1 0 -1 -2 0 10 20 30 40 50 TIME (ns) 60 70 80 90 100 INPUT VOLTAGE EDGES VOUT = 0V TO 2.5V
OVERLOAD BEHAVIOR AND RECOVERY
Input
The specified input common-mode voltage of the ADA4851-1/ ADA4851-2/ADA4851-4 is 200 mV below the negative supply to within 2.2 V of the positive supply. Exceeding the top limit results in lower bandwidth and increased rise time, as seen in Figure 41 and Figure 42. Pushing the input voltage of a unitygain follower to less than 2 V from the positive supply leads to the behavior shown in Figure 43--an increasing amount of output error as well as a much increased settling time. The recovery time from input voltages 2.2 V or closer to the positive supply is approximately 55 ns, which is limited by the settling artifacts caused by transistors in the input stage coming out of saturation.
Figure 44. Overload Recovery
Rev. E | Page 14 of 20
05143-053
05143-051
3.0
2.00
ADA4851-1/ADA4851-2/ADA4851-4
SINGLE-SUPPLY VIDEO AMPLIFIER
The ADA4851 family of amplifiers is well suited for portable video applications. When operating in low voltage single-supply applications, the input signal is limited by the input stage headroom. For additional information, see the Headroom Considerations section. Table 6 illustrates the effects of supply voltage, input signal, various gains, and output signal swing for the typical video amplifier shown in Figure 45.
RF +VS C1 2.2F + RG PD U1 VIN
IOUT R2 R3 47 125 C1 51pF R4 2k +3V
An example of an 8 MHz, 3-pole, Sallen-Key, low-pass, video reconstruction filter is shown in Figure 46. This circuit features a gain of 3, has a 0.1 dB bandwidth of 8.2 MHz, and over 17 dB attenuation at 27 MHz (see Figure 47). The filter has three poles; two are active with a third passive pole (R6 and C4) placed at the output. C3 improves the filter roll-off. R6, R7, and R8 comprise the video load of 150 . Components R6, C4, R7, R8, and the input termination of the network analyzer form a 12.8 dB attenuator; therefore, the reference level is roughly -3.3 dB, as shown in Figure 47.
C2 51pF
C2 0.01F V
75
75 CABLE
VOUT
05143-059
VIDEO DAC
R6 6.8
R7 68.1 C4 1nF R8 75
R1 37.4
VOUT
75
Table 6. Recommended Values
Supply Voltage (V) 3 3 5 Input Range (V) 0 to 0.8 0 to 0.8 0 to 2.8
Figure 46. 8 MHz Video Reconstruction Filter Schematic
RG (k) 1 0.499 1
RF (k) 1 1 1
Gain (V/V) 2 3 2
V' (V) 1.6 2.4 4.9
VOUT (V) 0.8 1.2 2.45
5dB/REF -15dB
1: -3.3931dB
8.239 626MHz
1
VIDEO RECONSTRUCTION FILTER
At higher frequencies, active filters require wider bandwidths to work properly. Excessive phase shift introduced by lower frequency op amps can significantly affect the filter performance. A common application for active filters is at the output of video DACs/encoders. The filter, or more appropriately, the video reconstruction filter is used at the output of a video DAC/ encoder to eliminate the multiple images that are created during the sampling process within the DAC. For portable video applications, the ADA4851-x is an ideal choice due to its lower power requirements and high performance.
05143-062
0.03
0.1
1 FREQUENCY (MHz)
10
100
Figure 47. Video Reconstruction Filter Frequency Performance
Rev. E | Page 15 of 20
05143-061
Figure 45. Video Amplifier
R5 1k
C3 6.8pF
ADA4851-1/ADA4851-2/ADA4851-4 OUTLINE DIMENSIONS
2.90 BSC
6
5
4
1.60 BSC
1 2 3
2.80 BSC
PIN 1 INDICATOR 0.95 BSC 1.30 1.15 0.90 1.90 BSC
1.45 MAX 0.50 0.30
0.22 0.08 10 4 0 0.60 0.45 0.30
0.15 MAX
SEATING PLANE
COMPLIANT TO JEDEC STANDARDS MO-178-AB
Figure 48. 6-Lead Small Outline Transistor Package [SOT-23] (RJ-6) Dimensions shown in millimeters
3.20 3.00 2.80
3.20 3.00 2.80 PIN 1
8
5
1
5.15 4.90 4.65
4
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 49. 8-Lead Mini Small Outline Package [MSOP] (RM-8) Dimensions shown in millimeters
Rev. E | Page 16 of 20
ADA4851-1/ADA4851-2/ADA4851-4
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 50. 14-Lead Thin Shrink Small Outline Package [TSSOP] (RU-14) Dimensions shown in millimeters
ORDERING GUIDE
Model ADA4851-1YRJZ-R2 1 ADA4851-1YRJZ-RL1 ADA4851-1YRJZ-RL71 ADA4851-2YRMZ1 ADA4851-2YRMZ-RL1 ADA4851-2YRMZ-RL71 ADA4851-4YRUZ1 ADA4851-4YRUZ-RL1 ADA4851-4YRUZ-R71
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
Package Description 6-Lead Small Outline Transistor Package (SOT-23) 6-Lead Small Outline Transistor Package (SOT-23) 6-Lead Small Outline Transistor Package (SOT-23) 8-Lead Mini Small Outline Package (MSOP) 8-Lead Mini Small Outline Package (MSOP) 8-Lead Mini Small Outline Package (MSOP) 14-Lead Thin Shrink Small Outline Package (TSSOP) 14-Lead Thin Shrink Small Outline Package (TSSOP) 14-Lead Thin Shrink Small Outline Package (TSSOP)
Package Option RJ-6 RJ-6 RJ-6 RM-8 RM-8 RM-8 RU-14 RU-14 RU-14
Branding HHB HHB HHB HSB HSB HSB
Z = RoHS Compliant Part.
Rev. E | Page 17 of 20
ADA4851-1/ADA4851-2/ADA4851-4 NOTES
Rev. E | Page 18 of 20
ADA4851-1/ADA4851-2/ADA4851-4 NOTES
Rev. E | Page 19 of 20
ADA4851-1/ADA4851-2/ADA4851-4 NOTES
(c) 2004-2007 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05143-0-8/07(E)
Rev. E | Page 20 of 20

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