Datasheet AD8003 Datasheet (ANALOG DEVICES)

Triple, 1.5 GHz Op Amp

FEATURES

High speed
1650 MHz (G = +1) 730 MHz (G = +2, VO = 2 V p-p) 4300 V/μs (G = +2, 4 V step) Settling time 12 ns to 0.1%, 2 V step
Excellent for QXGA resolution video
Gain flatness 0.1 dB to 190 MHz
0.05% differential gain error, R
0.01° differential phase error, R Low voltage offset: 0.7 mV (typical) Low input bias current: 7 μA (typical) Low noise: 1.8 nV/√Hz Low distortion over wide bandwidth: SFDR −73 dBc @ 20 MHz High output drive: 100 mA output load drive Supply operation: +5 V to ±5 V voltage supply Supply current: 9.5 mA/amplifier

APPLICATIONS

High resolution video graphics Professional video Consumer video High speed instrumentation Muxing

GENERAL DESCRIPTION

The AD8003 is a triple ultrahigh speed current feedback amplifier. Using ADI’s proprietary eXtra Fast Complementary Bipolar (XFCB) process, the AD8003 achieves a bandwidth of 1.5 GHz and a slew rate of 4300 V/μs. Additionally, the amplifier provides excellent dc precision with an input bias current of 50 μA maximum and a dc input voltage of 0.7 mV.
The AD8003 has excellent video specifications with a frequency response that remains flat out to 190 MHz and 0.1% settling within 12 ns to ensure that even the most demanding video systems maintain excellent fidelity. For applications that use NTSC video, as well as high speed video, the amplifier provides a differential gain of 0.05% and a differential gain of 0.01°.
The AD8003 has very low spurious-free dynamic range (SFDR) (−73 dBc @ 20 MHz) and noise (1.8 nV/√Hz). With a supply range between 5 V and 11 V and ability to source 100 mA of output current, the AD8003 is ideal for a variety of applications.
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.
= 150 Ω
L
= 150 Ω
L
AD8003

CONNECTION DIAGRAM

S2
FEEDBACK 2
+V
19
G=+5
+V
18
FEEDBACK 3
17
–IN 3
16
+IN 3
15
POWER DOWN 3
14
–V
13
G=+1
+V
FEEDBACK 1
–IN 1
+IN 1
POWER DOWN 1
–V
–VS2POWER DOWN 2
24 23 22 21 20
1
S1
2
3
4
5
6
S1
7 8 9 10 11 12
NC
+IN 2
–IN 2
OUT 1NCOUT 2NCOUT 3
Figure 1. 24-Lead, 4 mm × 4 mm LFCSP_VQ (CP-24)
The AD8003 operates on only 9.5 mA of supply current per amplifier. The independent power-down function of the AD8003 reduces the quiescent current even further to 1.6 mA.
The AD8003 amplifier is available in a compact 4 mm × 4 mm, 24-lead LFCSP_VQ. The AD8003 is rated to work over the industrial temperature range of −40°C to +85°C.
3
VS=±5V G=+1,R
2
G=+2,+5,R R
1
V
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-L OOP GAIN (dB)
–6
–7
1 100 1000
Figure 2. Large Signal Frequency Response for Various Gains
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 ©2005–2008 Analog Devices, Inc. All rights reserved.
=150
L OUT
=432
F
=2Vp-p
= 464
F
10
FREQUENCY (MHz)
G=+2
S3
S3
05721-001
05721-009
AD8003

TABLE OF CONTENTS

Features .............................................................................................. 1
Gain Configurations .................................................................. 12
Applications ....................................................................................... 1
Connection Diagram ....................................................................... 1
General Description ......................................................................... 1
Revision History ............................................................................... 2
Specifications with ±5 V Supply ..................................................... 3
Specifications with +5 V Supply ..................................................... 4
Absolute Maximum Ratings ............................................................ 5
Thermal Resistance ...................................................................... 5
ESD Caution .................................................................................. 5
Typical Performance Characteristics ............................................. 6
Applications Information .............................................................. 12

REVISION HISTORY

9/08—Rev. A to Rev. B
Changes Applications Section ......................................................... 1
Changes to Ordering Guide .......................................................... 15
RGB Video Driver ...................................................................... 12
Printed Circuit Board Layout ....................................................... 13
Low Distortion Pinout ............................................................... 13
Signal Routing ............................................................................. 13
Exposed Paddle ........................................................................... 13
Power Supply Bypassing ............................................................ 13
Grounding ................................................................................... 14
Outline Dimensions ....................................................................... 15
Ordering Guide .......................................................................... 15
2/06—Rev. 0 to Rev. A
Changes to Figure 34 ...................................................................... 11
10/05—Revision 0: Initial Version
Rev. B | Page 2 of 16
AD8003

SPECIFICATIONS WITH ±5 V SUPPLY

TA = 25°C, VS = ±5 V, RL = 150 Ω, Gain = +2, RF = 464 Ω, unless otherwise noted.
Table 1.
Parameter Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Bandwidth G = +1, Vo = 0.2 V p-p, RF = 432 Ω 1650 MHz G = +2, Vo = 2 V p-p 730 MHz G = +10, Vo = 0.2 V p-p 290 MHz G = +5, Vo = 2 V p-p 330 MHz Bandwidth for 0.1 dB Flatness Vo = 2 V p-p 190 MHz Slew Rate G = +2, Vo = 2 V step, RL = 150 Ω 3800 V/μs Settling Time to 0.1% G = +2, Vo = 2 V step 12 ns Overload Recovery Input/Output 30/40 ns
NOISE/HARMONIC PERFORMANCE
Second/Third Harmonic @ 5 MHz G = +1, Vo = 2 V p-p 76/97 dBc Second/Third Harmonic @ 20 MHz G = +1, Vo = 2 V p-p 79/73 dBc Input Voltage Noise f = 1 MHz 1.8 nV/√Hz
Input Current Noise (I−/I+) f = 1 MHz 36/3 pA/√Hz Differential Gain Error NTSC, G = +2, RL= 150 Ω 0.05 % Differential Phase Error NTSC, G = +2, RL= 150 Ω 0.01 Degree
DC PERFORMANCE
Input Offset Voltage −9.3 +0.7 +9.3 mV T Input Offset Voltage Drift 7.4 μV/°C Input Bias Current +IB/−IB −19/−40 −7/−7 +4/+50 μA T Input Offset Current ±14.2 μA Transimpedance Vo = ±2.5 V 400 600 1100
INPUT CHARACTERISTICS
Noninverting Input Impedance 1.6/3 MΩ/pF Input Common-Mode Voltage Range ±3.6 V Common-Mode Rejection Ratio VCM = ±2.5 V −51 −48 −46 dB
OUTPUT CHARACTERISTICS
Output Voltage Swing RL = 150 Ω ±3.85 ±3.9 ±3.92 V Linear Output Current VO = 2 V p-p, second harmonic < −50 dBc 100 mA Capacitive Load Drive 40% over shoot 27 pF
POWER DOWN PINS
Power-Down Input Voltage Power down <VS − 2.5 V Enable >VS − 2.5 V Turn-Off Time
Turn-On Time
Input Current
Enabled 0.1 μA Power-Down −365 −235 −85 μA
POWER SUPPLY
Operating Range 4.5 10 V Quiescent Current per Amplifier Enabled 8.1 9.5 10.2 mA Quiescent Current per Amplifier Power down 1.2 1.4 1.6 mA Power Supply Rejection Ratio (+PSRR/−PSRR) −59/−57 −57/−53 −55/−50 dB
− T
MIN
MIN
1.08 mV
MAX
− T
(+IB/−IB) −3.8/+29.5 μA
MAX
50% of power-down voltage to 10% of V
final, VIN = 0.5 V p-p
OUT
50% of power-down voltage to 90% of V
final, VIN = 0.5 V p-p
OUT
40 ns
130 ns
Rev. B | Page 3 of 16
AD8003

SPECIFICATIONS WITH +5 V SUPPLY

TA = 25°C, VS = 5 V, RL = 150 Ω, Gain = +2, RF = 464 Ω, unless otherwise noted.
Table 2.
Parameter Conditions Min Typ Max Unit
DYNAMIC PERFORMANCE
–3 dB Bandwidth G = +1, Vo = 0.2 V p-p, RF = 432 Ω 1050 MHz G = +2, Vo = 2 V p-p 590 MHz G = +10, Vo = 0.2 V p-p 290 MHz G = +5, Vo = 2 V p-p 310 MHz Bandwidth for 0.1 dB Flatness Vo = 2 V p-p 83 MHz Slew Rate G = +2, Vo = 2 V step, RL = 150 Ω 2860 V/μs Settling Time to 0.1% G = +2, Vo = 2 V step 12 ns Overload Recovery Input/Output 40/60 ns
NOISE/HARMONIC PERFORMANCE
Second/Third Harmonic @ 5 MHz G = +1, Vo = 2 V p-p 75/78 dBc Second/Third Harmonic @ 20 MHz G = +1, Vo = 2 V p-p 66/61 dBc Input Voltage Noise f = 1 MHz 1.8 nV/√Hz
Input Current Noise (I−/I+) f = 1 MHz 36/3 pA/√Hz Differential Gain Error NTSC, G = +2, RL= 150 Ω 0.04 % Differential Phase Error NTSC, G = +2, RL= 150 Ω 0.01 Degree
DC PERFORMANCE
Input Offset Voltage −6.5 +2.7 +11 mV T Input Offset Voltage Drift 14.2 μV/°C Input Bias Current (+IB/−IB) −21/−50 −7.7/−2.3 +5/+48 μA T Input Offset Current ±5.4 μA Transimpedance 300 530 1500
INPUT CHARACTERISTICS
Noninverting Input Impedance 1.6/3 MΩ/pF Input Common-Mode Voltage Range 1.3 to 3.7 V Common-Mode Rejection Ratio −50 −48 −45 dB
OUTPUT CHARACTERISTICS
Output Voltage Swing RL = 150 Ω ±1.52 ±1.57 ±1.62 V Linear Output Current VO = 2 V p-p, second harmonic < −50 dBc 70 mA Capacitive Load Drive 45% over shoot 27 pF
POWER DOWN PINS
Power-Down Input Voltage Power down <VS − 2.5 V Enable >VS − 2.5 V Turn-Off Time
Turn-On Time
Input Current
Enabled 0.1 μA Power-Down −160 −43 +80 μA
POWER SUPPLY
Operating Range 4.5 10 V Quiescent Current per Amplifier Enabled 6.3 7.9 9.4 mA Quiescent Current per Amplifier Power down 0.8 0.9 1.1 mA Power Supply Rejection Ratio (+PSRR/−PSRR) −59/−56 −57/−53 −55/−50 dB
− T
MIN
MIN
2.06 mV
MAX
− T
(+IB/−IB) −4/−27.8 μA
MAX
50% of power-down voltage to 10% of V
final, VIN = 0.5 V p-p
OUT
50% of power-down voltage to 90% of V
final, VIN = 0.5 V p-p
OUT
125 ns
80 ns
Rev. B | Page 4 of 16
AD8003
(

ABSOLUTE MAXIMUM RATINGS

Table 3.
Parameter Rating
Supply Voltage 11 V Power Dissipation See Figure 3 Common-Mode Input Voltage −VS − 0.7 V to +VS + 0.7 V Differential Input Voltage
±V
S
Exposed Paddle Voltage −VS Storage Temperature Range −65°C to +125°C Operating Temperature Range −40°C to +85°C Lead Temperature (Soldering 10 sec) 300°C 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
24-Lead LFCSP_VQ 70 °C/W

Maximum Power Dissipation

The maximum safe power dissipation for the AD8003 is limited by the associated rise in junction temperature (T 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 AD8003. Exceeding a junction temperature of 175°C for an extended period can result in changes in silicon devices, potentially causing degradation or loss of functionality.
) on the die. At
J
RMS output voltages should be considered. If R
, as in single-supply operation, the total drive power is VS ×
−V
S
I
. If the rms signal levels are indeterminate, consider the
OUT
worst case, when V
()
D
In single-supply operation with is
V
= VS/2.
OUT
= VS/4 for RL to midsupply.
OUT
2
)
4
/V
S
+×=
IVP
SS
R
L
R
referenced to −VS, worst case
L
Airflow increases heat dissipation, effectively reducing θ
is referenced to
L
.
JA
In addition, more metal directly in contact with the package leads and exposed paddle from metal traces, through holes, ground, and power planes reduce θ
.
JA
Figure 3 shows the maximum safe power dissipation in the package vs. the ambient temperature for the exposed paddle, 4 mm × 4 mm LFCSP_VQ (70°C/W) package on a JEDEC standard 4-layer board. θ
3.0
2.5
2.0
1.5
1.0
0.5
MAXIMUM POW ER DISSIPATION (W )
0
–35 –15 5 25 45 65 85 105
–55 125
Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
values are approximations.
JA
AMBIENT TEMPERATURE (°C)
05721-037

ESD CAUTION

The power dissipated in the package (P
) is the sum of the
D
quiescent power dissipation and the power dissipated in the die due to the AD8003 drive at the output. The quiescent power is the voltage between the supply pins (V current (I
).
S
= Quiescent Power + (Total Drive PowerLoad Power)
P
D
V
V
()
D
IVP
SS
⎜ ⎝
OUTS
×+×=
R
2
L
) times the quiescent
S
⎞ ⎟
⎟ ⎠
2
V
OUT
R
L
Rev. B | Page 5 of 16
AD8003

TYPICAL PERFORMANCE CHARACTERISTICS

3
VS = ±5V R
= 464
F
2
R
= 150
L
V
= 200mV p-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
–7
1 10 100 1000
FREQUENCY (MHz)
G = –1
G = –2
Figure 4. Small Signal Frequency Response for Various Gains
05721-002
3
VS=±5V G=+1,R
2
G=+2,+10,R R
1
V
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
–7
1 100 1000
= 150
L
= 200mV p -p
OUT
=432
F
= 464
F
10
FREQUENCY (MHz)
G=+2
G=+1
G=+10
Figure 7. Small Signal Frequency Response for Various Gains
05721-003
3
G = +2 R
= 150
L
2
V
= 200mV p-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
–7
1 100 1000
10
FREQUENCY (MHz)
VS = ±5V
VS = +5V
Figure 5. Small Signal Frequency Response for Various Supplies
3
G = +2 V
= ±5V
S
2
R
= 150
L
V
= 200mV p-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
–7
1 100 1000
10
FREQUENCY (MHz)
Figure 6. Small Signal Feedback Resistor (R
RF = 392
RF = 432
RF = 464
RF = 357
) Optimization
F
3
G = +2 V
= ±5V
S
2
R
= 150
L
V
= 200mV p-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
05721-004
–7
1 100 1000
10
FREQUENCY (MHz)
T = +105°C
T = +25°C
T = –40°C
05721-005
Figure 8. Small Signal Frequency Response for Various Temperatures
3
G = +2 V
= ±5V
S
2
R
= 150
L
V
= 2V p-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-LOOP GAIN (dB)
–6
05721-007
–7
1 100 1000
10
FREQUENCY (MHz)
RF = 392
RF = 432
RF = 357
RF = 464
05721-008
Figure 9. Large Signal Feedback Resistor (RF) Optimization
Rev. B | Page 6 of 16
AD8003
6
G = +1 V
=±5V
S
R
= 150
L
V
= 200mV p-p
3
OUT
0
–3
–6
–9
NORMALIZED CL OSED-LOO P GAIN ( dB)
–12
1 10 100 1000 10000
FREQUENCY (MHz)
Figure 10. G = +1 Series Resistor (R
3
VS=±5V G=+1,R
2
G=+2,+5,R R
1
V
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-L OOP GAIN (dB)
–6
–7
1 100 1000
=150
L OUT
=432
F
=2Vp-p
= 464
F
10
FREQUENCY (MHz)
G=+2
RS = 50
) Optimization
S
G=+5
R
0
=
S
RS = 25
G=+1
Figure 11. Large Signal Frequency Response for Various Gains
30
G=+1 R
= 100
L
–40
–50
–60
–70
–80
–90
DISTORTION (dBc)
–100
–110
–120
=2Vp-p
V
OUT
SECOND
THIRD
0.1 1 10 100 FREQUENCY (MHz)
VS=±5V V
=+5V
S
Figure 12. Harmonic Distortion vs. Frequency for Various Supplies
05721-006
05721-009
05721-017
0.3 G = +2
R
= 150
0.2
L
V
= 2V p-p
OUT
0.1
0
–0.1
–0.2
–0.3
–0.4
–0.5
–0.6
–0.7
NORMALIZED CL OSED-LOO P GAIN ( dB)
–0.8
–0.9
1 10 100 1000
FREQUENCY (MHz )
VS =±5V
VS =+5V
Figure 13. 0.1 dB Flatness Response
3
VS=±5V G=+2
2
R
= 150
L
V
=2Vp-p
OUT
1
0
–1
–2
–3
–4
–5
NORMALIZED CLOSED-L OOP GAIN (dB)
–6
–7
1 100 1000
10
FREQUENCY (MHz)
T = + 105°C
T = –40° C
T = +25°C
05721-010
Figure 14. Large Signal Frequency Response for Various Temperatures
30
G=+2 R
=150
L
–40
V
=2Vp-p
OUT
–50
–60
–70
–80
–90
DISTORTION (dBc)
–100
–110
–120
0.1 1 10 100
SECOND
THIRD
FREQUENCY ( MHz)
VS=±5V V
=+5V
S
05721-018
Figure 15. Harmonic Distortion vs. Frequency for Various Supplies
05721-016
Rev. B | Page 7 of 16
AD8003
–20
–30
–40
10
G = +2 V
OUT
f
= 5MHz
C
= 2V p-p
SECOND
VS =±5V V
=+5V
S
0.20
0.15
0.10
0.05
V
VS=
G=+2 R
= 150
L
V
= 200mV p -p
+
5
V
=
S
±
5
V
OUT
2.70
2.65
2.60
2.55
–50
–60
DISTORTION (dBc)
–70
–80
–90
10 12 14 16 18 20 22 24 26 28 30
THIRD
R
()
L
Figure 16. Harmonic Distortion vs. R
L
05721-019
0
–0.05
OUTPUT VO LTAGE (V )
–0.10
–0.15
–0.20
01
1234567891011121314
Figure 19. Small Signal Pulse Response for Various Supplies
2.0 G = +2
= 150
R
L
= 2V p-p
V
1.5
OUT
1.0
0.5
0
–0.5
OUTPUT VO LTAGE (V )
–1.0
–1.5
–2.0
015
=
VS
+
5
V
V
±
5
V
=
S
1 2 3 4 5 6 7 8 9 10 11 12 13 14
TIME (ns)
4.5
4.0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
OUTPUT VOLTAGE ( V)
05721-012
Figure 17. Large Signal Pulse Response for Various Supplies
0.3
0.2
0.1
0
–0.1
OUTPUT VOLTAGE (V)
G=+2
–0.2
= 150
R
L
V
=±5V
S
= 200mV p -p
V
OUT
–0.3
0 5 10 15 20 25 30 35
Figure 20. Small Signal Pulse Response for Various Capacitive Loads
TIME (ns)
CL=0pF
C
L
TIME (ns)
= 15pF
C
L
= 27pF
2.50
2.45
OUTPUT VO LTAGE (V )
2.40
2.35
2.30
5
5721-011
05721-020
2.8
2.7
2.6
=15pF
C
2.5
CL=0pF
2.4
OUTPUT VOLTAGE (V)
G=+2
2.3
= 150
R
L
=5V
V
S
= 200mV p -p
V
OUT
2.2
0 5 10 15 20 25 30 3 5
L
C
TIME (ns)
= 27pF
L
Figure 18. Small Signal Pulse Response for Various Capacitive Loads
05721-022
Rev. B | Page 8 of 16
AMPLITUDE (V)
–0.5
–1.0
–1.5
1.5 G=+2
V
=±5V
S
R
= 150
L
1.0
0.5
0
–5
0105 152025303540 45
V
V
SETTLE
TIME (ns)
OUT
V
IN
Figure 21. Short-Term 0.1% Settling Time
0.3
0.2
0.1
0
–0.1
–0.2
–0.3
SETTLING (%)
05721-021
AD8003
(
6000
G=+2 R
= 150
L
5000
4000
3000
2000
SLEW RATE (V/µs)
1000
0
123456
07
VS=
V
+
5
V
V
OUT p-p
±
5
V
=
S
(V)
RISE FALL
05721-013
Figure 22. Slew Rate vs. Output Voltage
5
4
3
2
1
0
–1
AMPLITUDE (V)
–2
–3
–4
–5
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
OUTPUT
INPUT × 2
TIME (µs)
G = +2 V
= ±5V
S
= 150
R
L
05721-024
Figure 23. Output Overdrive Recovery
0
G=0 V
=±5V
S
R
= 150
L
–10
–20
–30
–40
COMMON-MO DE REJECTIO N (dB)
–50
5
4
3
2
1
0
–1
AMPLITUDE (V)
–2
–3
–4
–5
0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1.0
OUTPUT
INPUT
TIME (µs)
G = +1 V R
Figure 25. Input Overdrive Recovery
1000
G=+1/+2 V
=±5V
S
100
)
10
IMPEDANCE
1
0.1
0.1 1 10 100 1000 FREQUENCY (MHz)
Figure 26. Output Impedance vs. Frequency
0
G=+2 V
=±5V
S
R
= 150
L
–10
–20
–30
–40
–50
POWER SUPPLY REJECTI ON (dB)
–60
PSR–
PSR+
= ±5V
S
= 150
L
05721-023
05721-027
–60
0.1 1 10 100 FREQUENCY ( MHz)
Figure 24. Common-Mode Rejection vs. Frequency
05721-026
Rev. B | Page 9 of 16
–70
0.1 1 10 100 1000 FREQUENCY ( MHz)
Figure 27. Power Supply Rejection vs. Frequency
05721-025
AD8003
(
80
20
60
VS=±5V
40
VS=+5V
20
(mV)
OS
0
V
–20
–40
–60
–5 –4 –3 –2 –1 0 1 2 3 4
(V)
V
CM
Figure 28. Offset Voltage vs. Input Common-Mode Range
10
8
VS = +5V
6
4
VS = ±5V
2
0
(μA)
B
I
–2
–4
–6
–8
–10
–5 –4 –3 –2 –1 0 1 2 3 4
V
(V)
OUT
Figure 29. Inverting Input Bias Current Linearity
15
VS=±5V
10
VS=+5V
5
µA)
0
B
I
–5
–10
–15
05721-031
5
–20
–5 –4 –3 –2 –1 0 1 2 3 4
V
(V)
CM
05721-032
5
Figure 31. Noninverting Input Bias Current vs. Common-Mode Range
6
V
D
±
5
V
V
=
S
(
S
I
)
5
4
V
V
(
S
D
I
+
5
V
=
S
3
AMPLITUDE (V)
2
V
V
U
(
T
O
V
O
U
)
+
=
S
5
V
)
±
5
V
=
S
(
T
V
)
1
V
U
(
T
O
±
5
V
V
=
)
05721-033
5
0
01
0.1 0.2 0.3 0.4 0.5 0.6 0. 7 0.8 0.9
S
TIME (µs)
V
O
G=+2 R
=150
L
V
=0.5Vdc
IN
V
U
(
T
+
=
S
5
V
)
05721-014
.0
Figure 32. Disable Switching Time for Various Supplies
10
G=+2 R
=150
L
9
V
=±5V
S
8
7
6
I
S
D
I
5
4
3
2
POSITIVE SUPPLY CURRENT (mA)
I
1
0
4–3–2–101234
–5 5
POWERDOWNPINVOLTAGE(V
DIS
(V))
Figure 30. POWER DOWN Pin Current and Supply Current vs.
POWER DOWN Pin Voltage
200
150
100
50
0
–50
–100
–150
C
C
–200
POWER DOW N PIN CURRENT (µA)
–250
–300
05721-028
10
G=+2 R
=150
L
9
V
=5V
S
8
7
6
I
C
C
5
4
3
2
POSITIVE SUPPLY CURRENT (mA)
1
0
05
0.51.01.52.02.53.03.54.04.5 POWERDOWNPINVOLTAGE(V
DIS
(V))
40
30
20
10
I
S
D
I
0
–10
–20
–30
–40
POWER DOW N PIN CURRENT (µA)
–50
–60
.0
05721-029
Figure 33. POWER DOWN Pin Current and Supply Current vs.
POWER DOWN Pin Voltage
Rev. B | Page 10 of 16
AD8003
1000
VS =±5V R
= 1k
F
100
10
INPUT VOLTAGE NOISE (nV/√Hz)
1
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
Figure 34. Input Voltage Noise vs. Frequency
0
G=+2 R
= 150
L
–10
DRIVING: CH1 AND CH3 RECEIVING: CH2
–20
–30
–40
–50
–60
–70
–80
NORMALIZE D CLOSED-LOOP GAIN (dB)
–90
–100
0.1 1 10 100 1000 FREQUENCY ( MHz)
VS=
Figure 35. Worst-Case Crosstalk
VS=
05721-034
±
5
V
+
5
V
05721-015
10000
VS=±5V
Hz)
1000
100
10
INPUT CURRENT NOI SE (pA/
1
10 100 1k 10k 100k 1M 10M
FREQUENCY (Hz)
Figure 36. Input Current Noise vs. Frequency
1M
100k
10k
MAGNITUDE (Ω)
1k
100
1k 10k 100k 1M 10M 100M 1G
FREQUENCY (Hz)
Figure 37. Transimpedance
I–
I+
05721-035
200
180
160
140
120
100
80
PHASE (Degrees )
60
40
20
0
05721-030
Rev. B | Page 11 of 16
AD8003
T

APPLICATIONS INFORMATION

GAIN CONFIGURATIONS

Unlike conventional voltage feedback amplifiers, the feedback resistor has a direct impact on the closed-loop bandwidth and stability of the current feedback op amp circuit. Reducing the resistance below the recommended value can make the amplifier response peak and can even become unstable. Increasing the size of the feedback resistor reduces the closed-loop bandwidth.
Table 5 provides a convenient reference for quickly determining the feedback and gain set resistor values, and the small and large signal bandwidths for common gain configurations. The feedback resistors in Tab le 5 have been optimized for 0.1 dB flatness frequency response.
Table 5. Recommended Values and Frequency Response1
Gain RF (Ω) RG (Ω) RS (Ω)
−1 300 300 0 734 668 -­+1 432 N/A 24.9 1650 822 -­+2 464 464 0 761 730 190 +5 300 75 0 567 558 165 +10 300 33.2 0 446 422 170
1
Conditions: VS = ±5 V, TA = 25°C, RL = 150 Ω.
Figure 38 and Figure 39 show the typical noninverting and inverting configurations and recommended bypass capacitor values.
R
G
R
V
IN
V
IN
S
Figure 38. Noninverting Gain
R
G
R
F
AD8003
+
–V
R
F
AD8003
+
FB
–V
S
FB
–V
−3 dB SS BW (MHz)
+V
S
+V
0.1µF
10µF
+V
S
+V
0.1µF
10µF
0.1µF
10µF
0.1µF
Large Signal
−3 dB BW
V
O
V
O
Large Signal
0.1 dB BW
V
O
R
L
05721-038
V
O
R
L

RGB VIDEO DRIVER

Figure 40 shows a typical RGB driver application using bipolar
75
75
75
= RG =
F
R
OUT
G
OU
B
OUT
supplies. The gain of the amplifier is set at +2, where R 464 Ω. The amplifier inputs are terminated with shunt 75 Ω resistors, and the outputs have series 75 Ω resistors for proper video matching. In Figure 40, the POWER DOWN pins are not shown connected to any signal source for simplicity. If the power­down function is not used, it is recommended that the POWER DOWN pins be tied to the positive supply and not be left floating (not connected).
In applications that require a fixed gain of +2, as previously mentioned, the designer may consider the ADA4862-3. The ADA4862-3 is another high performance triple current feedback amplifier. The ADA4862-3 has integrated feedback and gain set resistors that reduce board area and simplify designs.
PD3
PD2
PD1
+V
14
23
5
1
R
IN
75
G
IN
75
B
IN
75
R
464
R
464
R
464
R
464
R
464
R
464
4
G
3
F
2
AD8003
22
G
21
F
20
15
G
16
F
17
6
19
24
18
13
Figure 40. RGB Video Driver
10µF
0.1µF
10µF
0.1µF
10µF
0.1µF
10µF
0.1µF
10µF
0.1µF
10µF
0.1µF
S
–V
S
+V
S
–V
S
+V
S
–V
S
05721-036
10µF
–V
S
Figure 39. Inverting Gain
05721-039
Rev. B | Page 12 of 16
AD8003

PRINTED CIRCUIT BOARD LAYOUT

Printed circuit board (PCB) layout is usually one of the last steps in the design process and often proves to be one of the most critical. A high performance design can be rendered mediocre due to poor or sloppy layout. Because the AD8003 can operate into the RF frequency spectrum, high frequency board layout considerations must be taken into account. The PCB layout, signal routing, power supply bypassing, and grounding must all be addressed to ensure optimal performance.

LOW DISTORTION PINOUT

The AD8003 LFCSP features ADI’s low distortion pinout. The pinout lowers the second harmonic distortion and simplifies the circuit layout. The close proximity of the noninverting input and the negative supply pin creates a source of second harmonic distortion. Physical separation of the noninverting input pin and the negative power supply pin reduces this distortion.
By providing an additional output pin, the feedback resistor can be connected directly between the feedback pin and the inverting input. This greatly simplifies the routing of the feedback resistor and allows a more compact circuit layout, which reduces its size and helps to minimize parasitics and increase stability.

SIGNAL ROUTING

To minimize parasitic inductances, ground planes should be used under high frequency signal traces. However, the ground plane should be removed from under the input and output pins to minimize the formation of parasitic capacitors, which degrades phase margin. Signals that are susceptible to noise pickup should be run on the internal layers of the PCB, which can provide maximum shielding.

POWER SUPPLY BYPASSING

Power supply bypassing is a critical aspect of the PCB design process. For best performance, the AD8003 power supply pins need to be properly bypassed.
Each amplifier has its own supply pins brought out for the utmost flexibility. Supply pins can be commoned together or routed to a dedicated power plane. Commoned supply connections can also reduce the need for bypass capacitors on each supply line. The exact number and values of the bypass capacitors are dictated by the design specifications of the actual circuit.
A parallel combination of different value capacitors from each of the power supply pins to ground tends to work the best. Paralleling different values and sizes of capacitors helps to ensure that the power supply pins see a low ac impedance across a wide band of frequencies. This is important for minimizing the coupling of noise into the amplifier. Starting directly at the power supply pins, the smallest value and physical-sized component should be placed on the same side of the board as the amplifier, and as close as possible to the amplifier, and connected to the ground plane. This process should be repeated for the next largest capacitor value. It is recommended that a 0.1 μF ceramic 0508 case be used for the AD8003. The 0508 offers low series inductance and excellent high frequency performance. The 0.1 μF case provides low impedance at high frequencies. A 10 μF electrolytic capacitor should be placed in parallel with the 0.1 μF. The 10 μF capacitor provides low ac impedance at low frequencies. Smaller values of electrolytic capacitors can be used depending on the circuit requirements. Additional smaller value capacitors help provide a low impedance path for unwanted noise out to higher frequencies but are not always necessary.

EXPOSED PADDLE

The AD8003 features an exposed paddle, which lowers the thermal resistance by approximately 40% compared to a standard SOIC plastic package. The paddle can be soldered directly to the ground plane of the board. Thermal vias or heat pipes can also be incorporated into the design of the mounting pad for the exposed paddle. These additional vias improve the thermal transfer from the package to the PCB. Using a heavier weight copper also reduces the overall thermal resistance path to ground.
Rev. B | Page 13 of 16
Placement of the capacitor returns (grounds), where the capacitors enter into the ground plane, is also important. Returning the capacitor grounds close to the amplifier load is critical for distortion performance. Keeping the capacitors distance short, but equal from the load, is optimal for performance.
In some cases, bypassing between the two supplies can help improve PSRR and maintain distortion performance in crowded or difficult layouts. Designers should note this as another option for improving performance.
AD8003
Minimizing the trace length and widening the trace from the capacitors to the amplifier reduces the trace inductance. A series inductance with the parallel capacitance can form a tank circuit, which can introduce high frequency ringing at the output. This additional inductance can also contribute to increased distortion due to high frequency compression at the output. The use of vias should be minimized in the direct path to the amplifier power supply pins because vias can introduce parasitic inductance, which can lead to instability. When required, use multiple large diameter vias because this lowers the equivalent parasitic inductance.

GROUNDING

The use of ground and power planes is encouraged as a method of proving low impedance returns for power supply and signal currents. Ground and power planes can also help to reduce stray trace inductance and provide a low thermal path for the amplifier. Ground and power planes should not be used under any of the pins of the AD8003. The mounting pads and the ground or power planes can form a parasitic capacitance at the amplifiers input. Stray capacitance on the inverting input and the feedback resistor form a pole, which degrades the phase margin, leading to instability. Excessive stray capacitance on the output also forms a pole, which degrades phase margin.
Rev. B | Page 14 of 16
AD8003

OUTLINE DIMENSIONS

0.60 MAX
19
18
EXPOSED
(BOTTOM VIEW)
13
12
PAD
24
6
7
1
2.50 REF
PIN 1 INDICATOR
2.25
2.10 SQ
1.95
0.25 MIN
PIN 1
INDICATOR
1.00
0.85
0.80
12° MAX
SEATING PLANE
4.00
BSC SQ
TOP
VIEW
0.80 MAX
0.65 TYP
COMPLIANT TOJEDEC STANDARDS MO-220-VGGD-2
0.30
0.23
0.18
3.75
BSC SQ
0.20 REF
0.05 MAX
0.02 NOM
0.60 MAX
0.50
BSC
0.50
0.40
0.30
COPLANARITY
0.08
Figure 41. 24-Lead Lead Frame Chip Scale Package [LFCSP_VQ]
4 mm × 4 mm Body, Very Thin Quad
(CP-24-1)
Dimensions shown in millimeters

ORDERING GUIDE

Model Temperature Range Package Description Package Option Ordering Quantity
AD8003ACPZ-R2 AD8003ACPZ-REEL AD8003ACPZ-REEL7 EVAL-AD8003-3CPEZ
1
Z = RoHS Compliant Part.
1
–40°C to +85°C 24-Lead LFCSP_VQ CP-24-1 250
1
–40°C to +85°C 24-Lead LFCSP_VQ CP-24-1 5,000
1
–40°C to +85°C 24-Lead LFCSP_VQ CP-24-1 1,500
1
Evaluation Board
Rev. B | Page 15 of 16
AD8003
NOTES
©2005–2008 Analog Devices, Inc. All rights reserved. Trademarks and registered trademarks are the property of their respective owners. D05721-0-9/08(B)
Rev. B | Page 16 of 16
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