AD ADA4430-1 Ultralow power video filter with power-down Datasheet

Ultralow Power Video Filter
with Power-Down
ADA4430-1
FEATURES
PIN CONFIGURATION
ADA4430-1
VIN
1
GND
2
×1
2×R
6
VS
5
DIS
4
VOUT
SAG
3
2×R
2×R
05885-001
R
Figure 1.
6.5
6.0
VS = 3V
VS = 5V
5.5
GAIN (dB)
Qualified for automotive applications
6th-order performance, low-pass video filter
1 dB flatness out to 8 MHz
50 dB rejection at 27 MHz
Ultralow power-down current: 0.1 μA typical
Low quiescent current: 1.85 mA typical
Excellent video specification
Differential gain: 0.25%
Differential phase: 0.10°
SAG correction
Allows use of small capacitors in ac-coupled outputs
Low supply voltage: 2.5 V to 6 V
Rail-to-rail output
High input-to-output isolation in disabled state
92 dB at 1 MHz
Low input bias current: 0.5 μA
Small packaging: SC70 and SOT-23 (automotive grade only)
Wide operating temperature range: −40°C to +125°C
5.0
4.5
APPLICATIONS
4.0
3.5
3.0
05885-006
Automotive infotainment (SOT-23 only)
Automotive rearview cameras (SOT-23 only)
Portable media players
Portable gaming consoles
Cell phones
Digital still cameras
Portable DVD players
Portable video cameras
10
1
FREQUENCY (MHz)
Figure 2. Frequency Response Flatness at Various Power Supplies
GENERAL DESCRIPTION
The ADA4430-1 is a fully integrated video reconstruction filter
that combines excellent video specifications with low power
consumption and an ultralow power disable, making it ideal
for portable video filtering applications. With 1 dB frequency
flatness out to 8 MHz and 50 dB rejection at 27 MHz, the
ADA4430-1 is ideal in SD video applications, including
NTSC and PAL.
The ADA4430-1 operates on single supplies as low as 2.5 V and
as high as 6 V while providing the dynamic range required by
the most demanding video systems.
The ADA4430-1 also provides an on-chip dc offset to avoid
clipping of the sync tips at the filter output, as well as SAG
correction that permits smaller capacitor values to be used in
applications with ac-coupled outputs.
The ADA4430-1 is available in a two 6-lead packages. The SC70
for commercial applications and the SOT-23 for automotive
applications are rated to work in the extended temperature
range of −40°C to +125°C.
Rev. C
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.
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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 ©2006–2010 Analog Devices, Inc. All rights reserved.
ADA4430-1
TABLE OF CONTENTS
Features .............................................................................................. 1
Theory of Operation ...................................................................... 12
Applications ....................................................................................... 1
Overview ..................................................................................... 12
Pin Configuration ............................................................................. 1
Power Savings Using the ADA4430-1 ..................................... 12
General Description ......................................................................... 1
Applications Information .............................................................. 13
Revision History ............................................................................... 2
Examples Illustrating Output Coupling .................................. 13
Specifications..................................................................................... 3
Usable Input Voltage Range ...................................................... 14
Absolute Maximum Ratings............................................................ 5
SAG Correction Frequency Response ..................................... 14
Thermal Resistance ...................................................................... 5
Reconstruction Filter Applications .......................................... 15
ESD Caution .................................................................................. 5
Printed Circuit Board Layout ................................................... 16
Pin Configuration and Function Descriptions ............................. 6
Outline Dimensions ....................................................................... 17
Typical Performance Characteristics ............................................. 7
Ordering Guide .......................................................................... 18
Test Circuits ..................................................................................... 11
Automotive Products ................................................................. 18
REVISION HISTORY
9/10—Rev. B to Rev. C
Change Automotive Products Section Heading ......................... 18
6/10—Rev. A to Rev. B
Updated Pin Name PD to DIS Throughout .................................. 1
Added 6-Lead SOT-23 ....................................................... Universal
Changes to Features Section, General Description Section,
Applications Section, and Figure 1 ................................................. 1
Changes to Table 1 ............................................................................ 3
Changes to Table 2 ............................................................................ 4
Changes to Table 4, Maximum Power Dissipation Section, and
Figure 3 .............................................................................................. 5
Changes to Figure 4 and Table 5 ..................................................... 6
Changes to Figure 16 ........................................................................ 8
Changes to Figure 25 and Figure 26............................................. 11
Changes to Overview Section ....................................................... 12
Changes to Figure 29, Figure 30, and Figure 31 ......................... 13
Changes to Figure 33 and Figure 34............................................. 15
Added Figure 36; Renumbered Sequentially .............................. 17
Updated Outline Dimensions ....................................................... 17
Changes to Ordering Guide .......................................................... 18
Added Automotive Products Section .......................................... 18
6/06—Rev. 0 to Rev. A
Changes to Figure 1 ...........................................................................1
Changes to Figure 4 ...........................................................................5
3/06—Revision 0: Initial Version
Rev. C | Page 2 of 20
ADA4430-1
SPECIFICATIONS
VS = 3 V @ TA = 25°C, VIN = 1 V p-p, RL = 150 Ω, unless otherwise noted.
Table 1.
Parameter
ELECTRICAL SPECIFICATIONS
Quiescent Supply Current
Quiescent Supply Current
Quiescent Supply Current—Disabled
Quiescent Supply Current—Disabled
Supply Voltage
Input Voltage Range—Low/High
Input Resistance
Input Capacitance
Input Bias Current
Output Voltage Range—Low/High
Output Offset Voltage
Output Offset Voltage
PSRR
Pass-Band Gain
Input-to-Output Isolation—Disabled
FILTER CHARACTERISTICS
−3 dB Bandwidth
1 dB Flatness
Out-of-Band Rejection
Differential Gain
Differential Phase
Linear Output Current
Group Delay Variation
Signal-to-Noise Ratio
DISABLE
Disable Input Voltage
Test Conditions/Comments
Min
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
Limited by output range; see the Applications Information
section
ADA4430-1W only: TMIN to TMAX
Input referred, ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
f = 1 MHz
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
f = 27 MHz; ADA4430-1W only: TMIN to TMAX
Modulated 10-step ramp, sync tip at 0 V
Modulated 10-step ramp, sync tip at 0 V
Typ
Max
Unit
1.85
1.85
0.1
0.1
2.3
3
5
6
6
0/1.38
mA
mA
μA
μA
V
V
10
1
0.5
0.10/2.85
95
95
60
6
92
MΩ
pF
μA
V
mV
mV
dB
dB
dB
2.5
50
5.85
f = 100 kHz to 5 MHz
100% white signal, f = 100 kHz to 5 MHz
9.7
8.0
50
0.25
0.10
40
7
76
MHz
MHz
dB
%
Degrees
mA
ns
dB
Device disabled
Device enabled
<0.7
>1.1
V
V
Rev. C | Page 3 of 20
7
5.5
40
140
200
ADA4430-1
VS = 5 V @ TA = 25°C, VIN = 1 V p-p, RL = 150 Ω, unless otherwise noted.
Table 2.
Parameter
ELECTRICAL SPECIFICATIONS
Quiescent Supply Current
Quiescent Supply Current
Quiescent Supply Current—Disabled
Quiescent Supply Current—Disabled
Supply Voltage
Input Voltage Range—Low/High
Input Resistance
Input Capacitance
Input Bias Current
Output Voltage Range—Low/High
Output Offset Voltage
Output Offset Voltage
PSRR
Pass-Band Gain
Input-to-Output Isolation—Disabled
FILTER CHARACTERISTICS
−3 dB Bandwidth
1 dB Flatness
Out-of-Band Rejection
Differential Gain
Differential Phase
Linear Output Current
Group Delay Variation
Signal-to-Noise Ratio
DISABLE
Disable Input Voltage
Test Conditions/Comments
Min
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
Limited by output range; see the Applications
Information section
ADA4430-1W only: TMIN to TMAX
Input referred, ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
f = 1 MHz
ADA4430-1W only: TMIN to TMAX
ADA4430-1W only: TMIN to TMAX
f = 27 MHz, ADA4430-1W only: TMIN to TMAX
Modulated 10-step ramp, sync tip at 0 V
Modulated 10-step ramp, sync tip at 0 V
Typ
Max
Unit
2.0
2.0
0.2
0.2
2.4
3.1
10
15
6
0/2.35
mA
mA
μA
μA
V
V
10
1
0.5
0.10/4.80
100
100
61
6
92
MΩ
pF
μA
V
mV
mV
dB
dB
dB
2.5
50
5.85
f = 100 kHz to 5 MHz
100% white signal, f = 100 kHz to 5 MHz
9.5
7.9
50
0.25
0.15
40
7.1
76
MHz
MHz
dB
%
Degrees
mA
ns
dB
Device disabled
Device enabled
<0.8
>1
V
V
Rev. C | Page 4 of 20
7.2
5.5
40
145
200
ADA4430-1
ABSOLUTE MAXIMUM RATINGS
Table 3.
Rating
6V
See Figure 3
−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 a device soldered in the circuit board.
Figure 3 shows the maximum safe power dissipation in the
package vs. the ambient temperature for the 6-lead SC70
(430°C/W) and the 6-lead SOT-23 (170°C/W) on a JEDEC
standard 4-layer board.
Unit
°C/W
°C/W
Maximum Power Dissipation
The maximum safe power dissipation in the ADA4430-1
package 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 can change the
stresses that the package exerts on the die, permanently shifting
the parametric performance of the ADA4430-1. Exceeding a
junction temperature of 150°C for an extended period can
result in changes in the silicon devices, potentially causing
failure.
1.0
0.8
SOT-23
0.6
0.4
SC70
0.2
0
–40
–20
0
20
40
60
80
AMBIENT TEMPERATURE (°C)
100
120
05885-002
θJA
430
170
Airflow increases heat dissipation, effectively reducing θJA. In
addition, more metal directly in contact with the package leads
from metal traces, through holes, ground, and power planes
reduces the θJA.
1.2
Table 4. Thermal Resistance
Package Type
6-Lead SC70
6-Lead SOT-23
The power dissipated in the package (PD) is the sum of the
quiescent power dissipation and the power dissipated in the
package due to the load drive. The quiescent power is the
voltage between the supply pins (VS) times the quiescent
current (IS). The power dissipated due to the load drive depends
upon the particular application. The power due to load drive is
calculated by multiplying the load current by the associated
voltage drop across the device. RMS voltages and currents must
be used in these calculations.
MAXIMUM POWER DISSIPATION (W)
Parameter
Supply Voltage
Power Dissipation
Storage Temperature Range
Operating Temperature Range
Lead Temperature (Soldering 10 sec)
Junction Temperature
Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board
ESD CAUTION
Rev. C | Page 5 of 20
ADA4430-1
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
ADA4430-1
VIN
1
GND
2
×1
2×R
6
VS
5
DIS
4
VOUT
SAG
3
2×R
05885-041
R
2×R
Figure 4. 6-Lead SC70 and SOT23 Top View
Table 5. Pin Function Descriptions
Pin Number
1
2
3
4
5
6
Mnemonic
VIN
GND
SAG
VOUT
DIS
VS
Description
Input Voltage.
Ground.
Feedback Connection.
Output Voltage.
Disable.
Positive Power Supply.
Rev. C | Page 6 of 20
ADA4430-1
TYPICAL PERFORMANCE CHARACTERISTICS
6.5
VS = 3V
6.0
VS = 3V
VS = 5V
VS = 5V
5.5
GAIN (dB)
5.0
4.5
4.0
3.5
1
10
3.0
100
05885-006
9
6
3
0
–3
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
05885-003
GAIN (dB)
VS = 3 V, RL, = 150 Ω, VOUT = 2.0 V p-p, DIS = high, VOUT connected directly to SAG, TA = 25°C, unless otherwise noted.
FREQUENCY (MHz)
Figure 8. Frequency Response Flatness at Various Power Supplies
6.5
RL = 75Ω
RL = 150Ω
RL = 75Ω
6.0
RL = 150Ω
GAIN (dB)
5.5
5.0
4.5
4.0
1
10
05885-007
3.5
05885-004
GAIN (dB)
Figure 5. Frequency Response at Various Power Supplies
9
6
3
0
–3
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
3.0
100
1
FREQUENCY (MHz)
Figure 9. Frequency Response Flatness at Various Loads
6.5
+125°C
+25°C
–40°C
+125°C
6.0
GAIN (dB)
5.5
+25°C
5.0
–40°C
4.5
4.0
1
10
05885-008
3.5
05885-005
GAIN (dB)
10
FREQUENCY (MHz)
Figure 6. Frequency Response at Various Loads
9
6
3
0
–3
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
10
1
FREQUENCY (MHz)
3.0
100
1
FREQUENCY (MHz)
10
FREQUENCY (MHz)
Figure 7. Frequency Response at Various Temperatures
Figure 10. Frequency Response Flatness at Various Temperatures
Rev. C | Page 7 of 20
9
6
3
0
–3
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
65
60
VS = 3V
GROUP DELAY (ns)
2.0V p-p
0.2V p-p
1
10
55
50
VS = 5V
45
40
05885-012
35
05885-009
GAIN (dB)
ADA4430-1
30
100
1
FREQUENCY (MHz)
Figure 14. Group Delay at Various Power Supplies
0
NOISE SPECTRUM (NTSC)
INPUT REFERRED
BANDWIDTH 100kHz TO 5.0MHz
AMPLITUDE (0dB = 714mV p-p)
NOISE LEVEL = –76.8dB rms
INPUT REFERRED
–5
–15
PSRR (dB)
–20
–25
–30
3V
–35
–40
–45
–50
0
1
2
3
4
5
05885-013
–55
–60
–65
0.001
6
0.01
0.1
FREQUENCY (MHz)
–50
1
10
100
FREQUENCY (MHz)
Figure 12. Input-Referred Noise Spectral Density
–40
5V
–10
05885-010
(dB)
Figure 11. Frequency Response at Various Output Amplitudes
–50
–55
–60
–65
–70
–75
–80
–85
–90
–95
–100
–105
–110
–115
–120
–125
–130
–135
–140
–145
–150
100
10
FREQUENCY (MHz)
Figure 15. PSRR vs. Frequency at Various Power Supplies
10000
VIN = 1V p-p
VDIS = 0V
OUTPUT REFERRED
VDIS = 0V
IMPEDANCE (Ω)
–70
–80
–90
–100
1000
100
–120
–130
0.01
0.1
1
10
10
0.1
100
FREQUENCY (MHz)
05885-030
–110
05885-011
ISOLATION (dB)
–60
1
10
FREQUENCY (MHz)
100
Figure 16. Disabled Output Impedance vs. Frequency
Figure 13. Input-to-Output Isolation—Disabled vs. Frequency
Rev. C | Page 8 of 20
500
ADA4430-1
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
2.5
2.0
1.5
1.0
100ns/DIV
0
2.0
2.25
1.5
2.00
1.0
1.75
0.5
1.50
0
1.25
–1.0
0.75
–1.5
–2.0
50ns/DIV
0.25
–2.5
0
–3.0
Figure 20. Settling Time
3.5
3.5
DISABLE
DISABLE
3.0
2.5
2.5
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE (V)
–0.5
ERROR
1.00
Figure 17. Transient Response
3.0
2.5
OUTPUT
2.50
0.50
05885-015
0.5
3.0
INPUT × 2
2.75
2.0
1.5
1.0
0.5
OUTPUT
2.0
1.5
1.0
0.5
OUTPUT
–0.5
0
05885-019
1µs/DIV
05885-016
0
–0.5
500ns/DIV
Figure 18. Disable Assert Time
Figure 21. Disable Deassert Time
4.0
–0.10
3.0
2.0
1.5
1.0
0.5
0
–0.5
200ns/DIV
–1.0
05885-033
OUTPUT (V)
2.5
–0.11
–0.12
–0.13
–0.14
–0.15
–0.16
–0.17
–0.18
05885-031
DIFFERENCE BETWEEN VS AND VOUT (V)
OUTPUT
2 × INPUT
3.5
–0.19
–0.20
–40
–25
–10
5
20
35
50
65
TEMPERATURE (°C)
80
95
Figure 22. Output Swing Limits vs. Temperature
Figure 19. Overdrive Recovery
Rev. C | Page 9 of 20
ERROR (%)
3.00
110
125
05885-018
3.0
ADA4430-1
1.75
200
1.70
100
DISABLED (VDIS = 0V)
1.65
–40
–20
0
20
40
60
80
100
120
0
+125°C
–40°C
1.4
+25°C
1.2
1.0
0.8
0.6
0.4
0.2
0
TEMPERATURE (°C)
Figure 23. Power Supply Current vs. Temperature
1.6
05885-022
300
1.8
POWER SUPPLY CURRENT (mA)
1.80
2.0
POWER SUPPLY CURRENT–DISABLED (nA)
400
ENABLED (V DIS = 3V)
05885-021
POWER SUPPLY CURRENT–ENABLED (mA)
1.85
0
0.5
1.0
1.5
2.0
2.5
3.0
DISABLE VOLTAGE (V)
Figure 24. Power Supply Current vs. Disable Voltage at Various Temperatures
Rev. C | Page 10 of 20
ADA4430-1
TEST CIRCUITS
VS+
0.1µF
ADA4430-1
0.5V
5
DIS
TEST GENERATOR
1 VIN
50Ω
RL = 150Ω
×1
VOUT 4
2 GND
2.6kΩ
3 SAG
2.6kΩ 1.3kΩ 2.6kΩ
118Ω
TEST RECEIVER
86.6Ω
50Ω
05885-038
50Ω
6
VS
Figure 25. Test Circuit Used for Frequency Sweeps and Time-Domain Tests
VS+
0.1µF
ADA4430-1
DIS
1.0V
TEST GENERATOR
75Ω
220µF
5
150Ω
1 VIN
150Ω
2 GND
RL = 150Ω
×1
VOUT 4
2.6kΩ
75Ω
TEST RECEIVER
75Ω
2.6kΩ 1.3kΩ 2.6kΩ
05885-039
3 SAG
6
VS
Figure 26. Test Circuit Used for Differential Gain, Differential Phase, and Noise Tests
Rev. C | Page 11 of 20
ADA4430-1
THEORY OF OPERATION
The ADA4430-1 is designed for exceptional performance as
both a filter and a low power driver for portable video applications. This performance is achieved by providing high order
filtering without trading off power consumption or device size.
While consuming only 1.85 mA quiescent supply current, the
ADA4430-1 provides video output on a single-supply as low as
2.5 V. Such low power consumption and low supply operation
normally indicates a single op amp with a two- or three-pole
roll-off; however, the ADA4430-1 achieves a sixth-order roll-off
in addition to a 10 MΩ input impedance for easy clamping and
lower DAC output power requirements. When not in use, the
ADA44330-1 can be shut down to draw less than 0.1 μA of supply
current using the disable pin (DIS). Additionally, the ADA44301 is unique in that it is a high order filter that fits into an SC70
package.
The ADA4430-1 provides a minimum 1 dB bandwidth of
5.5 MHz and a typical stop-band rejection of 50 dB at 27 MHz.
Phase response is not sacrificed in spite of the exceptional
filtering performance of the ADA4430-1, as exhibited by its
group delay, which varies by only 7 ns from 100 kHz to 5 MHz.
The ADA4430-1 is intended for use in applications that have
both ac- and dc-coupled inputs and outputs. The rail-to-rail
buffer on the ADA4430-1 output is able to drive 2 V p-p video
signals into two doubly terminated video loads (150 Ω each) on
a single 2.5 V supply. The ADA4430-1 has a gain of 2 when the
SAG correction pin is tied directly to the output, which makes
up for the 6 dB termination loss. When the SAG feature is used
(see Figure 29), the ADA4430-1 has a low frequency gain of
2.5 (≈ 8 dB) and a high frequency gain of 2. Signal offsets and
supply levels must be considered when using the SAG correction
feature to ensure that there are no headroom issues.
The internal buffer at the ADA4430-1 input isolates the source
resistance feeding the ADA4430-1 from the internal filter networks.
High input impedance is also advantageous when using video
clamping circuits.
The output buffer feedback network used to create a gain of 2 is
connected internally to the GND pin and has a nominal impedance
of 5.2 kΩ. The current required to drive this feedback network
causes the overall supply current to vary based on the output
level. The feedback impedance was chosen specifically to
minimize excess current consumption while maintaining
optimal frequency behavior.
POWER SAVINGS USING THE ADA4430-1
Using a series source termination and a shunt load termination
on a low supply voltage with the ADA4430-1 realizes significant
power savings compared with driving a video cable directly from
a DAC output. Figure 27 shows a video DAC driving a cable
directly. Properly terminating the line results in the DAC driving
two 75 Ω loads and requires in excess of 30 mA to reach a fullscale level of 1.3 V. Figure 28 shows the same video load being
driven using the ADA4430-1 and a series-shunt termination. This
requires two times the output voltage to drive the equivalent of
150 Ω but only requires a little more than 15 mA to reach a fullscale output. When running on the same supply voltage as the
DAC, this results in nearly a factor of two reduction in power
compared with the circuit in Figure 27. The high level of
filtering provided by the ADA4430-1 lowers the requirements
on the DAC oversampling ratio, realizing further power savings.
On any given DAC, 8× and 16× oversampling ratios can require
twice the power consumption of a 4× oversampling ratio.
3V
VIDEO
DAC/
ENCODER
The high input impedance and low input capacitance of the
ADA4430-1 offer advantages in a number of low power
applications. In reconstruction filter applications, the DAC can
be placed in its lowest power mode, allowing the use of a largevalued load resistor. Using a large-valued load resistor does not
interfere with the frequency response of the ADA4430-1.
75Ω
75Ω
05885-034
The input range of the ADA4430-1 includes ground, while the
output range is limited by the saturation of the output devices.
Saturation occurs several tens of mV from the positive and
negative supply rails. For accurate reproduction of groundreferenced input signals, an internal offset is used to shift the
output up by 95 mV.
Figure 27. DAC Driving Video Cable Directly
3V
0.1µF
VIDEO
DAC/
ENCODER
Rev. C | Page 12 of 20
ADA4430-1
RL
75Ω
FILTER
G = +2
Figure 28. DAC Driving Video Cable Using the ADA4430-1
75Ω
05885-035
OVERVIEW
ADA4430-1
APPLICATIONS INFORMATION
SAG correction allows the use of two small, lower cost
capacitors in place of one large capacitor in applications with
ac-coupled outputs. Circuits with ac-coupled outputs consume
less power than those with dc-coupled outputs.
EXAMPLES ILLUSTRATING OUTPUT COUPLING
The ADA4430-1 is ideally suited for use as a reconstruction
filter that follows a video DAC or encoder. The application
circuits in Figure 29, Figure 30, and Figure 31 illustrate a
number of ways the ADA4430-1 can be used with a singlesupply current-output DAC on its input and its output ac- and
dc-coupled.
3V
0.1µF
DISABLE CONTROL
ADA4430-1
RL
6
VS
×1
VOUT 4
2 GND
2.6kΩ
3 SAG
2.6kΩ
47µF
75Ω
VIDEO OUT
1.3kΩ
2.6kΩ
05885-027
1 VIN
VIDEO
DAC/ENCODER
5
DIS
22µF
Figure 29. AC-Coupled Output with SAG Correction
3V
0.1µF
DISABLE CONTROL
ADA4430-1
1 VIN
VIDEO
DAC/ENCODER
RL
5
DIS
6
VS
×1
2 GND
VOUT 4
220µF 75Ω
VIDEO OUT
2.6kΩ
2.6kΩ
1.3kΩ
2.6kΩ
05885-028
3 SAG
Figure 30. Traditional AC-Coupled Output with 220 μF Coupling Capacitor
3V
0.1µF
DISABLE CONTROL
ADA4430-1
5
DIS
VIDEO
DAC/ENCODER
RL
2 GND
3 SAG
×1
VOUT 4
75Ω
VIDEO OUT
2.6kΩ
2.6kΩ
1.3kΩ
2.6kΩ
05885-029
1 VIN
6
VS
Figure 31. DC-Coupled Output
Rev. C | Page 13 of 20
ADA4430-1
USABLE INPUT VOLTAGE RANGE
SAG CORRECTION FREQUENCY RESPONSE
The output voltage range of the ADA4430-1 limits its usable
input voltage range. The lower end of the input range is
typically 0 V. The upper end of the usable input voltage
range is calculated as
When using the SAG corrected circuit, the gain from the input
to the immediate output of the ADA4430-1 is ×2.5 (≈8 dB) at
extremely low frequencies where the outer feedback loop
formed by the 22 μF capacitor effectively opens (see Figure 29)
and exhibits a second-order peak of approximately 11 dB at
about 5 Hz. This gain is approximately 7.5 dB at 30 Hz. The
extra gain must be accounted for when considering low
frequency input and output signal swings to keep them within
their specified limits. The gain from the ADA4430-1 input to
the load side of the 47 μF capacitor does not exhibit this
behavior; rather, it appears more like a single-pole highpass response. Figure 32 illustrates the SAG frequency response
immediately at the ADA4430-1 output and at the load side of the
47 μF capacitor.
12
10
8
6
4
2
0
–2
–4
–6
–8
–10
AT ADA4430-1 OUTPUT
AT LOAD SIDE OF 47µF CAPACITOR
1
10
100
1000
10000
05885-040
where:
VIN (max) is the upper end of the usable input voltage range.
VOM is the maximum output swing.
VOO is the output-referred offset voltage.
GAIN (dB)
VIN (max) = (VOM − VOO)/2
100000
FREQUENCY (Hz)
Figure 32. SAG Corrected Frequency Response at ADA4430-1 Output and
at the Load Side of the 47 μF Capacitor
Rev. C | Page 14 of 20
ADA4430-1
RECONSTRUCTION FILTER APPLICATIONS
The 1041 Ω resistor, RSET, shown in Figure 34, sets the DAC
output current to its minimum full-scale value of 5 mA, and the
262.5 Ω load resistor produces a full-scale voltage of 1.313 V at
the ADA4430-1 input.
Figure 33 illustrates how to use the ADA4430-1 as a dc-coupled
reconstruction filter with a pass-band gain of 2 following the
low power ADV7190/ADV7191 video encoder. One ADV7190/
ADV7191 output DAC is shown for illustrative purposes, and
the remaining portions of the ADV7190/ADV7191 are omitted.
The ADV7190/ADV7191 is operated in 4× oversampling mode.
The ADV7174 can produce a maximum full-scale DAC output
current of approximately 35 mA and is therefore capable of
driving the video cable directly; however, as shown in Figure 34,
the ADA4430-1 offers a lower power cable-driving option.
The 2.4 kΩ resistor, RSET, shown in Figure 33 sets the DAC
output current to its minimum full-scale value of 2.16 mA, and
the 600 Ω load resistor produces a full-scale voltage of 1.296 V
at the ADA4430-1 input.
Figure 34 reveals the details of how the ADA4430-1 saves
power when driving video cables with terminations at both
ends. A full-scale level at the DAC output produces 2.626 V at
the ADA4430-1 output, which in turn delivers 17.5 mA into
the cable. In the case shown in Figure 27, the output voltage is
1.313 V, but the current driven into the cable is 35 mA—twice
that required when the ADA4430-1 is used. Therefore, the
ADA4430-1 allows the video encoder to be operated at its
minimum full-scale output current, and it efficiently handles
the cable-driving burden.
Figure 34 illustrates another reconstruction filter application,
following the ADV7174 video encoder. As in Figure 33, one
ADV7174 output DAC is shown for illustrative purposes, and
the remaining portions of the ADV7174 are omitted.
3V
DISABLE CONTROL
0.1µF
ADA4430-1
0.1µF
17, 25, 29, 38, 43, 54, 63
1 VIN
600Ω
×1
VOUT 4
2 GND
2.6kΩ
3 SAG
2.6kΩ 1.3kΩ 2.6kΩ
75Ω
75Ω CABLE
75Ω
05885-036
VAA
ADV7190/ADV7191
DAC
AGND
RSET
34, 48
18, 24, 26, 33,
2.4kΩ
39, 42, 55, 64
6
VS
5
DIS
Figure 33. Using the ADA4430-1 with the ADV7190/ADV7191 Video Encoder
3V
DISABLE CONTROL
0.1µF
0.1µF
ADA4430-1
2, 10, 18, 25, 27
1041Ω
(931Ω + 110Ω)
1 VIN
×1
VOUT 4
2 GND
2.6kΩ
3 SAG
2.6kΩ 1.3kΩ 2.6kΩ
75Ω
75Ω CABLE
75Ω
05885-037
VAA
ADV7174 DAC
RSET
AGND
262.5Ω
(191Ω + 71.5Ω)
31
6-9, 11, 12,
17, 19, 26, 40
5 6
DIS VS
Figure 34. Using the ADA4430-1 with the ADV7174 Video Encoder
Rev. C | Page 15 of 20
ADA4430-1
PRINTED CIRCUIT BOARD LAYOUT
As with all high speed applications, attention to printed circuit
board layout is of paramount importance. Standard high speed
layout practices should be adhered to when designing with the
ADA4430-1. A solid ground plane is recommended, and a 0.1 μF
surface-mount, ceramic power supply, decoupling capacitor should
be placed as close as possible to the supply pin.
When the ADA4430-1 receives its inputs from a device with
current outputs, the required load resistor value for the output
current is most often different from the characteristic impedance of
the signal traces. In this case, if the interconnections are sufficiently
short (less than 2 inches), the trace does not have to be
terminated in its characteristic impedance.
The GND pin should be connected to the ground plane with a
trace that is as short as possible. Controlled impedance traces of
the shortest length possible should be used to connect to the signal
I/O pins and should not pass over any voids in the ground plane. A
75 Ω impedance level is typically used in video applications. All
signal outputs of the ADA4430-1 should include series termination
resistors when driving transmission lines.
Rev. C | Page 16 of 20
ADA4430-1
OUTLINE DIMENSIONS
2.20
2.00
1.80
6
5
4
1
2
3
2.40
2.10
1.80
0.65 BSC
1.30 BSC
1.00
0.90
0.70
0.40
0.10
1.10
0.80
0.10 MAX
COPLANARITY
0.10
SEATING
PLANE
0.30
0.15
0.46
0.36
0.26
0.22
0.08
072809-A
1.35
1.25
1.15
COMPLIANT TO JEDEC STANDARDS MO-203-AB
Figure 35. 6-Lead Thin Shrink Small Outline Transistor Package [SC70]
(KS-6)
Dimensions shown in millimeters
3.00
2.90
2.80
1.70
1.60
1.50
6
5
4
1
2
3
PIN 1
INDICATOR
3.00
2.80
2.60
0.95 BSC
1.90
BSC
0.15 MAX
0.05 MIN
1.45 MAX
0.95 MIN
0.50 MAX
0.30 MIN
0.20 MAX
0.08 MIN
SEATING
PLANE
10°
4°
0°
0.60
BSC
COMPLIANT TO JEDEC STANDARDS MO-178-AB
Figure 36. 6-Lead Small Outline Transistor Package [SOT-23]
(RJ-6)
Dimensions shown in millimeters
Rev. C | Page 17 of 20
0.55
0.45
0.35
121608-A
1.30
1.15
0.90
ADA4430-1
ORDERING GUIDE
Model 1, 2
ADA4430-1YKSZ-R2
ADA4430-1YKSZ-R7
ADA4430-1YKSZ-RL
ADA4430-1WYRTZ-R7
1
2
Temperature Range
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
Package Description
6-Lead SC70
6-Lead SC70
6-Lead SC70
6-Lead SOT-23
Package Option
KS-6
KS-6
KS-6
RJ-6
Branding
H0G
H0G
H0G
H25
Ordering Quantity
250
3,000
10,000
3,000
Z = RoHS-Compliant Part.
W = Qualified for Automotive Applications.
AUTOMOTIVE PRODUCTS
The ADA4430-1W model is available with controlled manufacturing to support the quality and reliability requirements of automotive
applications. Note that these automotive models may have specifications that differ from the commercial models; therefore, designers
should review the Specifications section of this data sheet carefully. Only the automotive grade products shown are available for use in
automotive applications. Contact your local Analog Devices account representative for specific product ordering information and to
obtain the specific Automotive Reliability reports for these models.
Rev. C | Page 18 of 20
ADA4430-1
NOTES
Rev. C | Page 19 of 20
ADA4430-1
NOTES
©2006–2010 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05885-0-9/10(C)
Rev. C | Page 20 of 20