High Speed, G = +2,
Low Cost, Triple Op Amp
ADA4862-3
Rev. A
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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
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Tel: 781.329.4700 www.analog.com
Fax: 781.461.3113 © 2005 Analog Devices, Inc. All rights reserved.
FEATURES
Ideal for RGB/HD/SD video
Supports 1080i/720p resolution
High speed
−3 dB bandwidth: 300 MHz
Slew rate: 750 V/μs
Settling time: 9 ns ( 0.5%)
0.1 dB flatness: 65 MHz
Differential gain: 0.02%
Differential phase: 0.03°
Wide supply range: 5 V to 12 V
Low power: 5.3 mA/amp
Low voltage offset (RTO): 3.5 mV (typ)
High output current: 25 mA
Also configurable for gains of +1, −1
Power-down
APPLICATIONS
Consumer video
Professional video
Filter buffers
PIN CONFIGURATION
POWER DOWN 1
1
POWER DOWN 2
2
POWER DOWN 3
3
+V
S4
V
OUT
2
14
–IN 2
13
+IN 2
12
–V
S
11
+IN 1
5
+IN 3
10
–IN 1
6
–IN 3
9
V
OUT
1
7
V
OUT
3
8
ADA4862-3
550Ω550Ω
550Ω
550Ω550Ω
550Ω
05600-001
Figure 1. 14-Lead SOIC (R-14)
GENERAL DESCRIPTION
The ADA4862-3 (triple) is a low cost, high speed, internally
fixed, G = +2 op amp, which provides excellent overall
performance for high definition and RGB video applications.
The 300 MHz, G = +2, −3 dB bandwidth, and 750 V/μs slew
rate make this amplifier well suited for many high speed
applications. The ADA4862-3 can also be configured to
operate in gains of G = +1 and G = −1.
With its combination of low price, excellent differential gain
(0.02%), differential phase (0.03°), and 0.1 dB flatness out to
65 MHz, this amplifier is ideal for both consumer and
professional video applications.
The ADA4862-3 is designed to operate on supply voltages as
low as +5 V and up to ±5 V using only 5.3 mA/amp of supply
current. To further reduce power consumption, each amplifier
is equipped with a power-down feature that lowers the supply
current to 200 μA/amp. The ADA4862-3 also consumes less
board area because feedback and gain set resistors are on-chip.
Having the resistors on chip simplifies layout and minimizes the
required board space.
The ADA4862-3 is available in a 14-lead SOIC package and is
designed to work in the extended temperature range of −40°C
to +105°C.
6.1
5.1
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
1 10 100
6.0
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= +5V
V
S
= ±5V
05600-022
Figure 2. Large Signal 0.1 dB Bandwidth for Various Supplies
ADA4862-3
Rev. A | Page 2 of 16
TABLE OF CONTENTS
Features .............................................................................................. 1
Applications....................................................................................... 1
Pin Configuration............................................................................. 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 5
Thermal Resistance ...................................................................... 5
ESD Caution.................................................................................. 5
Typical Performance Characteristics ............................................. 6
Applications..................................................................................... 11
Using the ADA4862-3 in Gains = +1, −1................................ 11
Video Line Driver....................................................................... 13
Single-Supply Operation ........................................................... 13
Power Down................................................................................ 13
Layout Considerations............................................................... 14
Power Supply Bypassing ............................................................ 14
Outline Dimensions ....................................................................... 15
Ordering Guide .......................................................................... 15
REVISION HISTORY
8/05—Rev. 0 to Rev. A
Changes to Ordering Guide .......................................................... 15
7/05—Revision 0: Initial Version
ADA4862-3
Rev. A | Page 3 of 16
SPECIFICATIONS
VS = +5 V (@TA = 25oC, G = +2, RL = 150 Ω, unless otherwise noted).
Table 1.
Parameter Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Bandwidth VO = 0.2 V p-p 300 MHz
V
O = 2 V p-p 200 MHz
G = +1 VO = 0.2 V p-p 620 MHz
Bandwidth for 0.1 dB Flatness VO = 2 V p-p 65 MHz
+Slew Rate (Rising Edge) VO = 2 V p-p 750 V/μs
−Slew Rate (Falling Edge) VO = 2 V p-p 600 V/μs
Settling Time to 0.5% VO = 2 V step 9 ns
DISTORTION/NOISE PERFORMANCE
Harmonic Distortion HD2 fC = 1 MHz, VO = 2 V p-p −81 dBc
Harmonic Distortion HD3 fC = 1 MHz, VO = 2 V p-p −88 dBc
Harmonic Distortion HD2 fC = 5 MHz, VO = 2 V p-p −68 dBc
Harmonic Distortion HD3 fC = 5 MHz, VO = 2 V p-p −76 dBc
Voltage Noise (RTO) f = 100 kHz 10.6 nV/√Hz
Current Noise (RTI) f = 100 kHz, +IN 1.4 pA/√Hz
Differential Gain 0.02 %
Differential Phase 0.03 Degrees
Crosstalk Amplifier 1 driven, Amplifier 2 output
measured, f = 1 MHz
−75 dB
DC PERFORMANCE
Offset Voltage (RTO) Referred to output (RTO) −25 +3.5 +25 mV
+Input Bias Current −2.5 −0.6 +1 μA
Gain Accuracy 1.9 2 2.1 V/V
INPUT CHARACTERISTICS
Input Resistance +IN 13 MΩ
Input Capacitance +IN 2 pF
Input Common-Mode Voltage Range G = +1 1 to 4 V
POWER DOWN PIN
Input Voltage Enabled 0.6 V
Power down 1.8 V
Bias Current Enabled −3 μA
Power down 115 μA
Turn-On Time 3.5 μs
Turn-Off Time 200 ns
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time (Rise/Fall) VIN = +2.25 V to −0.25 V 85/50 ns
Output Voltage Swing RL = 150 Ω 1.2 to 3.8 V
Output Voltage Swing RL = 1 kΩ 1 to 4 V
Short-Circuit Current Sinking or sourcing 65 mA
POWER SUPPLY
Operating Range 5 12 V
Total Quiescent Current Enabled 14 16 18 mA
Quiescent Current /Amplifier Power down = +VS 0.2 0.33 mA
Power Supply Rejection Ratio (RTO) dB
+PSR +VS = 2 V to 3 V, −VS = −2.5 V −52 −55 dB
−PSR +VS = 2.5 V, −VS = −2 V to −3 V
Power Down pin = −VS
−49 −52 dB
ADA4862-3
Rev. A | Page 4 of 16
VS = ±5 V (@TA = +25oC, G = +2, RL = 150 Ω, unless otherwise noted).
Table 2.
Parameter Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Bandwidth VO = 0.2 V p-p 310 MHz
V
O = 2 V p-p 260 MHz
G = +1 VO = 0.2 V p-p 720 MHz
Bandwidth for 0.1 dB Flatness VO = 2 V p-p 54 MHz
+Slew Rate (Rising Edge) VO = 2 V p-p 1050 V/μs
−Slew Rate (Falling Edge) VO = 2 V p-p 830 V/μs
Settling Time to 0.5% VO = 2 V step 9 ns
DISTORTION/NOISE PERFORMANCE
Harmonic Distortion HD2 fC = 1 MHz, VO = 2 V p-p −87 dBc
Harmonic Distortion HD3 fC = 1 MHz, VO = 2 V p-p −100 dBc
Harmonic Distortion HD2 fC = 5 MHz, VO = 2 V p-p −74 dBc
Harmonic Distortion HD3 fC = 5 MHz, VO = 2 V p-p −90 dBc
Voltage Noise (RTO) f = 100 kHz 10.6 nV/√Hz
Current Noise (RTI) f = 100 kHz, +IN 1.4 pA/√Hz
Differential Gain 0.01 %
Differential Phase 0.02 Degrees
Crosstalk Amplifier 1 driven, Amplifier 2 output
measured, f = 1 MHz
−75 dB
DC PERFORMANCE
Offset Voltage (RTO) −25 +2 +25 mV
+Input Bias Current −2.5 −0.6 +1 μA
Gain Accuracy 1.9 2 2.1 V/V
INPUT CHARACTERISTICS
Input Resistance +IN 14 MΩ
Input Capacitance +IN 2 pF
Input Common-Mode Voltage Range G = +1 −3.7 to +3.8 V
POWER DOWN PIN
Input Voltage Enabled −4.4 V
Power down −3.2 V
Bias Current Enabled −3 μA
Power down 250 μA
Turn-On Time 3.5 μs
Turn-Off Time 200 ns
OUTPUT CHARACTERISTICS
Output Overdrive Recovery Time (Rise/Fall) VIN = ±3.0 V 85/40 ns
Output Voltage Swing RL = 150 Ω −3.5 to +3.5 V
Output Voltage Swing RL = 1 kΩ −3.9 to +3.9 V
Short-Circuit Current Sinking or sourcing 115 mA
POWER SUPPLY
Operating Range 5 12 V
Total Quiescent Current Enabled 14.5 17.9 20.5 mA
Quiescent Current/Amplifier Power down = +VS 0.3 0.5 mA
Power Supply Rejection Ratio (RTO) dB
+PSR +VS = 4 V to 6 V, −VS = −5 V −54 −57 dB
−PSR +VS = 5 V, −VS = −4 V to −6 V,
Power Down pin = −VS
+50.5 −54 dB
ADA4862-3
Rev. A | Page 5 of 16
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
Supply Voltage 12.6 V
Power Dissipation See Figure 3
Common-Mode Input Voltage ±VS
Storage Temperature −65°C to +125°C
Operating Temperature Range −40°C to +105°C
Lead Temperature JEDEC J-STD-20
Junction Temperature 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 device soldered in circuit board for surface-mount
packages.
Table 4. Thermal Resistance
Package Type θJA Unit
14-lead SOIC 90 °C/W
Maximum Power Dissipation
The maximum safe power dissipation for the ADA4862-3 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 amplifiers. Exceeding a
junction temperature of 150°C 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 amplifier’s drive at the output. The quiescent power is the
voltage between the supply pins (VS) × the quiescent current (IS).
PD = Quiescent Power + (Total Dr ive Powe r − Load Power)
()
L
OUT
L
OUT
S
SS
DR
V
R
VV
IVP
2
–
2⎟
⎠
⎞
⎜
⎝
⎛×+×=
RMS output voltages should be considered.
Airflow increases heat dissipation, effectively reducing θJA.
In addition, more metal directly in contact with the package
leads and through holes under the device reduces θJA.
Figure 3 shows the maximum safe power dissipation in the
package vs. the ambient temperature for the 14-lead SOIC
(90°C/W) on a JEDEC standard 4-layer board. θJA values are
approximations.
2.5
0
AMBIENT TEMPERATURE (°C)
MAXIMUM POWER DISSIPATION (W)
05600-036
–55 125–45 –35 –25 –15 –5 5 15 25 35 45 55 65 75 85 95 105 115
2.0
1.5
1.0
0.5
Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
ESD CAUTION
ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on
the human body and test equipment and can discharge without detection. Although this product features
proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy
electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance
degradation or loss of functionality.
ADA4862-3
Rev. A | Page 6 of 16
TYPICAL PERFORMANCE CHARACTERISTICS
8
0
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
1 10 100
7
6
5
4
3
2
1
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 0.2V p-p V
S
= +5V
V
S
= ±5V
05600-004
Figure 4. Small Signal Frequency Response for Various Supplies
8
0
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
1 10 100
7
6
5
4
3
2
1
V
S
= ±5V
V
S
= +5V
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
05600-012
Figure 5. Large Signal Frequency Response for Various Supplies
6.1
5.1
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
1 10 100
6.0
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= +5V
V
S
= ±5V
05600-022
Figure 6. Large Signal 0.1 dB Bandwidth for Various Supplies
200 2.7
–200 2.3
100 2.6
0 2.5
–100 2.4
V
S
= +5V
V
S
= ±5V
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 0.2V p-p
TIME = 5ns/DIV
05600-028
OUTPUT VOLTAGE (mV)
±V
S
= 5V
OUTPUT VOLTAGE (V)
+V
S
= 5V, –V
S
= 0V
Figure 7. Small Signal Transient Response for Various Supplies
200
–200
OUTPUT VOLTAGE (V)
150
100
50
0
–50
–100
–150
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 0.2V p-p
V
S
= ±5V
TIME = 5ns/DIV
C
L
= 9pF
C
L
= 6pF
C
L
= 4pF
05600-016
Figure 8. Small Signal Transient Response for Various Capacitor Loads
OUTPUT VOLTAGE (V)
2.7
2.3
2.6
2.5
2.4
C
L
= 6pF
C
L
= 9pF
C
L
= 4pF
G = +2
R
L
= 150Ω
V
OUT
= 0.2V p-p
V
S
= 5V
TIME = 5ns/DIV
05600-014
Figure 9. Small Signal Transient Response for Various Capacitor Loads
ADA4862-3
Rev. A | Page 7 of 16
1.5 4.0
–1.5 1.0
OUTPUT VOLTAGE (V)
±V
S
= 5V
OUTPUT VOLTAGE (V)
+V
S
= 5V, –V
S
= 0V
1.0 3.5
0.5 3.0
0 2.5
–0.5 2.0
–1.0 1.5
V
S
= +5V
V
S
= ±5V
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
TIME = 5ns/DIV
05600-010
Figure 10. Large Signal Transient Response for Various Supplies
1.5
–1.5
OUTPUT VOLTAGE (V)
1.0
0.5
0
–0.5
–1.0
C
L
= 9pF
C
L
= 6pF
C
L
= 4pF
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= ±5V
TIME = 5ns/DIV
05600-018
Figure 11. Large Signal Transient Response for Various Capacitor Loads
4.0
1.0
OUTPUT VOLTAGE (V)
3.5
3.0
2.5
2.0
1.5
C
L
= 4pF
C
L
= 9pF
C
L
= 6pF
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= 5V
TIME = 5ns/DIV
05600-019
Figure 12. Large Signal Transient Response for Various Capacitor Loads
6
–60 1000
TIME (ns)
OUTPUT AND INPUT VOLTAGE (V)
05600-042
5
4
3
2
1
0
–1
–2
–3
–4
–5
100 200 300 400 500 600 700 800 900
V
S
= ±5V
G = +2
R
L
= 150Ω
C
L
= 4pF
f = 1MHz
V
OUT
INPUT VOLTAGE × 2
Figure 13. Input Overdrive Recovery
5.5
–0.50 1000
TIME (ns)
OUTPUT AND INPUT VOLTAGE (V)
05600-041
5.0
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
100 200 300 400 500 600 700 800 900
V
S
= 5V
G = +2
R
L
= 150Ω
C
L
= 4pF
f = 1MHz
V
OUT
INPUT VOLTAGE × 2
Figure 14. Output Overdrive Recovery
ADA4862-3
Rev. A | Page 8 of 16
TIME (ns)
V
OUT
AND V
IN
(V)
V
OUT
EXPANDED (mV)
05600-043
1.5
–1.505
0
1.0
0.5
0
–0.5
–1.0
5 1015202530354045 –20
–15
–10
–5
0
5
10
15
20
1.5
–1.5050
TIME (ns)
VOUT AND VIN (V)
VOUT EXPANDED (mV)
05600-046
–20
–15
–10
–5
0
5
10
15
20
V
S
= ±5V, +5V
G = +2
V
OUT
= 2V p-p
R
L
=150Ω
C
L
= 4pF
V
OUT
EXPANDED
V
OUT
V
IN
Figure 15. Settling Time Falling Edge
1600
00 5.0
OUTPUT VOLTAGE STEP (V p-p)
SLEW RATE (V/μs)
1400
1200
1000
800
600
400
200
0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
G = +2
V
S
= ±5V
R
L
= 150Ω
C
L
= 4pF POSITIVE SLEW RATE
NEGATIVE SLEW RATE
05600-005
Figure 16. Slew Rate vs. Output Voltage
100
110 100M
05600-037
FREQUENCY (Hz)
VOLTAGE NOISE (nV/ Hz)
100 1k 10k 100k 1M 10M
10
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= ±5V
V
S
= +5V
Figure 17. Voltage Noise vs. Frequency Referred to Output (RTO)
VOUT
1.0
0.5
0
–0.5
–1.0
VIN
VOUT
EXPANDED VS = ±5V, +5V
G = +2
VOUT = 2V p-p
RL = 150Ω
CL = 4pF
5 1015202530354045
Figure 18. Settling Time Rising Edge
800
00 3.0
OUTPUT VOLTAGE STEP (V p-p)
SLEW RATE (V/
μ
s)
700
600
500
400
300
200
100
0.5 1.0 1.5 2.0 2.5
G = +2
V
S
= 5V
R
L
= 150Ω
C
L
= 4pF POSITIVE SLEW RATE
NEGATIVE SLEW RATE
05600-006
Figure 19. Slew Rate vs. Output Voltage
0
–120
0.1 1000
FREQUENCY (MHz)
CROSSTALK (dB)
1 10 100
–20
–40
–60
–80
–100
G = +2
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
V
S
= ±5V
V
S
= +5V
05600-023
Figure 20. Large Signal Crosstalk
ADA4862-3
Rev. A | Page 9 of 16
19
15412
SUPPLY VOLTAGE (V)
TOTAL SUPPLY CURRENT (mA)
18
17
16
567891011
05600-026
Figure 21. Total Supply Current vs. VSUPPLY
20
12
–40 125
TEMPERATURE (°C)
TOTAL SUPPLY CURRENT (mA)
19
18
17
16
15
14
13
–25–105 203550658095110
V
S
= ±5V
V
S
= +5V
05600-021
Figure 22. Total Supply Current at Various Supplies vs. Temperature
0
–70
0.01 1000
FREQUENCY (MHz)
POWER SUPPLY REJECTION (dB)
05600-051
0.1 1 10 100
–10
–20
–30
–40
–50
–60
VS = ±5V
–PSR
+PSR
Figure 23. Power Supply Rejection vs. Frequency
0
0.01 1000
FREQUENCY (MHz)
POWER SUPPLY REJECTION (dB)
05600-052
0.1 1 10 100
–10
–20
–30
–40
–50
–60
V
S
= ±2.5V
–PSR
+PSR
Figure 24. Power Supply Rejection vs. Frequency
ADA4862-3
Rev. A | Page 10 of 16
–50
–11004
OUTPUT VOLTAGE (V p-p)
DISTORTION (dBc)
05600-049
–60
–70
–80
–90
–100
123
f
O
= 1MHz
f
O
= 2MHz
f
O
= 5MHz
f
O
= 10MHz f
O
= 20MHz
G = +2
R
L
= 150Ω
C
L
= 4pF
HD2
V
S
= ±5V
Figure 25. HD2 vs. Frequency vs. Output Voltage
–50
–1100 2.5
OUTPUT VOLTAGE (V p-p)
DISTORTION (dBc)
05600-050
–60
–70
–80
–90
–100
G = +2
R
L
= 150Ω
C
L
= 4pF
HD2
V
S
= 5V
f
O
= 2MHz
f
O
= 1MHz
f
O
= 10MHz
f
O
= 20MHz
f
O
= 5MHz
0.5 1.0 1.5 2.0
Figure 26. HD2 vs. Frequency vs. Output Voltage
–50
–13004
OUTPUT VOLTAGE (V p-p)
DISTORTION (dBc)
05600-054
–60
–70
–80
–90
–100
–110
–120
123
G = +2
R
L
= 150Ω
C
L
= 4pF
HD3
V
S
= ±5V f
O
= 20MHz
f
O
= 5MHz
f
O
= 2MHz
f
O
= 1MHz
f
O
= 10MHz
Figure 27. HD3 vs. Frequency vs. Output Voltage
–50
–1300 2.5
OUTPUT VOLTAGE (V p-p)
DISTORTION (dBc)
05600-048
–60
–70
–80
–90
–100
–110
–120
0.5 1.0 1.5 2.0
f
O
= 20MHz
f
O
= 5MHz
f
O
= 2MHz
f
O
= 1MHz G = +2
R
L
= 150Ω
C
L
= 4pF
HD3
V
S
= +5V
f
O
= 10MHz
Figure 28. HD3 vs. Frequency vs. Output Voltage
ADA4862-3
Rev. A | Page 11 of 16
APPLICATIONS
USING THE ADA4862-3 IN GAINS = +1, −1
The ADA4862-3 was designed to offer outstanding video
performance, simplify applications, and minimize board area.
The ADA4862-3 is a triple amplifier with on-chip feedback and
gain set resistors. The gain is fixed internally at G = +2. The
inclusion of the on-chip resistors not only simplifies the design
of the application but also eliminates six surface-mount
resistors, saving valuable board space and lowers assembly
costs. A typical schematic is shown in Figure 29.
0.01μF
0.01μF
VIN RT
VOUT
+VS
–VS
GAIN OF +2
05600-029
10μF
10μF
Figure 29. Noninverting Configuration (G = +2)
While the ADA4862-3 has a fixed gain of G = +2, it can be used
in other gain configurations, such as G = −1 and G = +1, which
are discussed next.
Unity-Gain Operation (Option 1)
There are two options for obtaining unity gain (G = +1). The
first is shown in Figure 30. In this configuration, the –IN input
pin is left floating (feedback is provided via the internal 550 Ω),
and the input is applied to the noninverting input. The noise
gain for this configuration is 1. Frequency performance and
transient response are shown in Figure 31 through Figure 33.
0.01μF
10μF
10μF
0.01μF
V
IN
R
T
V
OUT
+V
S
–V
S
GAIN OF +1
05600-032
Figure 30. Unity Gain of Option 1
4
–4
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
05600-053
1 10 100
3
2
1
0
–1
–2
–3
G = +1
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 200mV p-p
V
S
= ±5V
V
S
= +5V
Figure 31. Small Signal Unity Gain
3
–6
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
05600-002
1 10 100
2
1
0
–1
–2
–3
–4
–5
V
S
= +5V
V
S
= ±5V
G = +1
R
L
= 150Ω
C
L
= 4pF
V
OUT
= 2V p-p
Figure 32. Large Signal Gain +1
2.0
–2.0
OUTPUT VOLTAGE (V)
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
C
L
= 4pF
C
L
= 9pF
C
L
= 6pF
G = +1
R
L
= 150Ω
V
OUT
= 2V p-p
V
S
= ±5V
TIME = 5ns/DIV
05600-020
Figure 33. Large Signal Transient Response for Various Capacitor Loads
ADA4862-3
Rev. A | Page 12 of 16
Option 2
Another option exists for running the ADA4862-3 as a unity-
gain amplifier. In this configuration, the noise gain is 2, see
Figure 34. The frequency response and transient response for
this configuration closely match the gain of +2 plots because the
noise gains are equal. This method does have twice the noise
gain of Option 1; however, in applications that do not require
low noise, Option 2 offers less peaking and ringing. By tying the
inputs together, the net gain of the amplifier becomes 1.
Equation 1 shows the transfer characteristic for the schematic
shown in Figure 34. Frequency and transient response are
shown in Figure 35 and Figure 36.
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛+
+
⎟
⎟
⎠
⎞
⎜
⎜
⎝
⎛−
=
G
G
F
i
G
F
i
OR
RR
V
R
R
VV (1)
which simplifies to VO = Vi.
0.01μF
0.01μF
V
IN
R
T
V
OUT
+V
S
–V
S
GAIN OF +1
05600-030
10μF
10μF
R
F
R
G
Figure 34. Unity Gain of Option 2
1
–7
0.1 1000
FREQUENCY (MHz)
GAIN (dB)
1 10 100
0
–1
–2
–3
–4
–5
–6
G = +1
R
L
= 150Ω
05600-027
Figure 35. Frequency Response of Option 2
05600-039
G = +1
V
S
= ±5V
R
L
= 150Ω
TIME = 2ns/DIV
200
OUTPUT VOLTAGE (mV)
150
100
50
0
–50
–100
–150
–200
Figure 36. Small Signals Transient Response of Option 2
0.01μF
0.01μF
V
IN
R
T
V
OUT
+V
S
–V
S
GAIN OF –1
05600-031
10μF
10μF
Figure 37. Inverting Configuration (G = −1)
2.0
–2.0
OUTPUT VOLTAGE (V)
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
C
L
= 9pF
C
L
= 6pF
C
L
= 4pF
G = –1
R
L
= 150Ω
V
OUT
= 2V p-p
V
S
= ±5V
TIME = 5ns/DIV
05600-017
Figure 38. Large Signal Transient Response for Various Capacitor Loads
ADA4862-3
Rev. A | Page 13 of 16
VIDEO LINE DRIVER
The ADA4862-3 was designed to excel in video driver
applications. Figure 39 shows a typical schematic for a video
driver operating on a bipolar supplies.
75Ω
CABLE
75Ω
75ΩV
OUT
–V
S
+V
S
V
IN
0.1μF
0.1μF
10μF
10μF
75Ω
CABLE
75Ω
05600-033
ADA4862-3
+
–
Figure 39. Video Driver Schematic
In applications that require two video loads be driven
simultaneously, the ADA4862-3 can deliver. Figure 40 shows
the ADA4862-3 configured with dual video loads. Figure 41
shows the dual video load performance.
75Ω
CABLE
75Ω
CABLE
75Ω
75Ω
75Ω
75Ω
V
OUT
2
V
OUT
1
–V
S
+V
S
V
IN
0.1μF
0.1μF
10μF
10μF
75Ω
CABLE
75Ω
05600-034
+
2
1
8
7
6
–
Figure 40. Video Driver Schematic for Two Video Loads
8
0
0.1 1000
FREQUENCY (MHz)
CLOSED-LOOP GAIN (dB)
1 10 100
7
6
5
4
3
2
1
G = +2
R
L
= 75Ω
C
L
= 4pF
V
OUT
= 2V p-p V
S
= ±5V
V
S
= +5V
05600-008
Figure 41. Large Signal Frequency Response for Various Supplies, RL = 75 Ω
SINGLE-SUPPLY OPERATION
The ADA4862-3 can also operate in single-supply applications.
Figure 42 shows the schematic for a single 5 V supply video
driver. Resistors R2 and R4 establish the midsupply reference.
Capacitor C2 is the bypass capacitor for the midsupply
reference. Capacitor C1 is the input coupling capacitor, and C6
is the output coupling capacitor. Capacitor C5 prevents constant
current from being drawn through the internal gain set resistor.
Resistor R3 sets the circuits ac input impedance.
For more information on single-supply operation of op amps,
see www.analog.com/library/analogDialogue/archives/35-
02/avoiding/.
C2
1μF
R2
50kΩR4
50kΩ
R3
1kΩ
C1
22μF
R1
50Ω
C6
220μF
R5
75ΩR6
75Ω
C5
22μF
ADA4862-3
+5V
05600-035
V
OUT
V
IN
–V
S
C3
2.2μF
C4
0.01μF
+5V
Figure 42. Single-Supply Video Driver Schematic
POWER DOWN
The ADA4862-3 is equipped with an independent Power Down
pin for each amplifier allowing the user to reduce the supply
current when an amplifier is inactive. The voltage applied to the
−VS pin is the logic reference, making single-supply applications
useful with conventional logic levels. In a typical 5 V single-
supply application, the −VS pin is connected to analog ground.
The amplifiers are powered down when applied logic levels are
greater than −VS + 1 V. The amplifiers are enabled whenever the
disable pins are left either floating (disconnected) or the
applied logic levels are lower than 1 V above −VS.
ADA4862-3
Rev. A | Page 14 of 16
LAYOUT CONSIDERATIONS
As is the case with all high speed applications, careful attention
to printed circuit board layout details prevents associated board
parasitics from becoming problematic. Proper RF design
technique is mandatory. The PCB should have a ground plane
covering all unused portions of the component side of the
board to provide a low impedance return path. Removing the
ground plane on all layers from the area near the input and
output pins reduces stray capacitance. Termination resistors and
loads should be located as close as possible to their respective
inputs and outputs. Input and output traces should be kept as
far apart as possible to minimize coupling (crosstalk) though
the board. Adherence to microstrip or stripline design
techniques for long signal traces (greater than about 1 inch) is
recommended.
POWER SUPPLY BYPASSING
Careful attention must be paid to bypassing the power supply
pins of the ADA4862-3. High quality capacitors with low
equivalent series resistance (ESR), such as multilayer ceramic
capacitors (MLCCs), should be used to minimize supply voltage
ripple and power dissipation. A large, usually tantalum, 10 μF to
47 μF capacitor located in proximity to the ADA4862-3 is
required to provide good decoupling for lower frequency
signals. In addition, 0.1 μF MLCC decoupling capacitors should
be located as close to each of the power supply pins as is
physically possible, no more than 1/8 inch away. The ground
returns should terminate immediately into the ground plane.
Locating the bypass capacitor return close to the load return
minimizes ground loops and improves performance.
ADA4862-3
Rev. A | Page 15 of 16
OUTLINE DIMENSIONS
CONTROLLING DIMENSIONS ARE IN MILLIMETERS; INCH DIMENSIONS
(IN PARENTHESES) ARE ROUNDED-OFF MILLIMETER EQUIVALENTS FOR
REFERENCE ONLY AND ARE NOT APPROPRIATE FOR USE IN DESIGN
COMPLIANT TO JEDEC STANDARDS MS-012-AB
COPLANARITY
0.10
14 8
7
1
6.20 (0.2441)
5.80 (0.2283)
4.00 (0.1575)
3.80 (0.1496)
8.75 (0.3445)
8.55 (0.3366)
1.27 (0.0500)
BSC
SEATING
PLANE
0.25 (0.0098)
0.10 (0.0039)
0.51 (0.0201)
0.31 (0.0122)
1.75 (0.0689)
1.35 (0.0531)
8°
0°
0.50 (0.0197)
0.25 (0.0098)
1.27 (0.0500)
0.40 (0.0157)
0.25 (0.0098)
0.17 (0.0067)
× 45°
Figure 43. 14-Lead Standard Small Outline Package [SOIC_N]
Narrow Body
(R-14)
Dimensions shown in millimeters and (inches)
ORDERING GUIDE
Model Temperature Range Package Description Ordering Quantity Package Option
ADA4862-3YRZ1–40°C to +105°C 14-Lead SOIC_N 1 R-14
ADA4862-3YRZ-RL1–40°C to +105°C 14-Lead SOIC_N 2,500 R-14
ADA4862-3YRZ-RL71–40°C to +105°C 14-Lead SOIC_N 1,000 R-14
1 Z = Pb-free part.
ADA4862-3
Rev. A | Page 16 of 16
NOTES
© 2005 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05600–0–8/05(A)
