ADA4430-1YKSZ-R7 [ADI]
Ultralow Power Video Filter with Power-Down; 超低功耗视频滤波器具有掉电
| 型号： | ADA4430-1YKSZ-R7 |
| 厂家： | 
ADI |
| 描述： | Ultralow Power Video Filter with Power-Down |
| 文件： | 总16页 (文件大小：392K) |
| 中文： | 中文翻译 | 下载： | 下载PDF数据表文档文件 |
Ultralow Power Video Filter
with Power-Down
ADA4430-1
FEATURES
6th-order performance, low-pass video filter
PIN CONFIGURATION
ADA4430-1
1 dB flatness out to 8 MHz
50 dB rejection at 27 MHz
Ultralow power-down current: 0.1 μA typ
Low quiescent current: 1.85 mA typ
Excellent video specification
Differential gain: 0.25%
V
x1
V +
S
1
2
3
6
5
4
IN
2*R
2*R
GND
SAG
PD
R
Differential phase: 0.10°
SAG correction
2*R
V
OUT
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 @ 1 MHz
Low input bias current: 0.5 μA
Small packaging: SC70
Wide operating temperature range: −40°C to +125°C
Figure 1.
6.5
6.0
5.5
5.0
4.5
4.0
3.5
3.0
V
= 3V
S
V
= 5V
S
APPLICATIONS
Portable media players
Portable gaming consoles
Cell phones
Digital still cameras
Portable DVD players
Portable video cameras
1
10
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 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 6-lead SC70 package and is
rated to work in the extended automotive temperature range of
−40°C to +125°C.
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.
Rev. A
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 registeredtrademarks arethe property of their respective owners.
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781.329.4700
Fax: 781.461.3113
www.analog.com
©2006 Analog Devices, Inc. All rights reserved.
ADA4430-1
TABLE OF CONTENTS
Features .............................................................................................. 1
Theory of Operation ...................................................................... 11
Overview ..................................................................................... 11
Power Savings Using the ADA4430-1 ..................................... 11
Applications..................................................................................... 12
Examples Illustrating Output Coupling.................................. 12
Usable Input Voltage Range ...................................................... 13
SAG Correction Frequency Response..................................... 13
Reconstruction Filter Applications.......................................... 14
Printed Circuit Board Layout ................................................... 15
Outline Dimensions....................................................................... 16
Ordering Guide .......................................................................... 16
Applications....................................................................................... 1
Pin Configuration............................................................................. 1
General Description......................................................................... 1
Revision History ............................................................................... 2
Specifications..................................................................................... 3
Absolute Maximum Ratings............................................................ 4
Thermal Resistance ...................................................................... 4
ESD Caution.................................................................................. 4
Pin Configuration and Function Descriptions............................. 5
Typical Performance Characteristics ............................................. 6
Test Circuits ..................................................................................... 10
REVISION HISTORY
6/06—Rev. 0 to Rev. A
Changes to Figure 1.......................................................................... 1
Changes to Figure 4.......................................................................... 5
3/06—Revision 0: Initial Version
Rev. A | Page 2 of 16
ADA4430-1
SPECIFICATIONS
VS = 3 V @ TA = 25°C, VIN = 1 V p-p, RL = 150 Ω, unless otherwise noted.
Table 1.
Parameter
Test Conditions/Comments
Min Typ
Max Unit
ELECTRICAL SPECIFICATIONS
Quiescent Supply Current
Quiescent Supply Current—Disabled
Supply Voltage
1.85
0.1
2.5
2.3
5
6
mA
μA
V
Input Voltage Range—Low/High
Input Resistance
Input Capacitance
Limited by output range; see the Applications section
0/1.38
10
1
0.5
V
MΩ
pF
μA
V
mV
dB
dB
dB
Input Bias Current
Output Voltage Range—Low/High
Output Offset Voltage
PSRR
0.10/2.85
95
60
6
140
Input referred
f = 1 MHz
50
5.85
Pass-Band Gain
Input-to-Output Isolation—Disabled
FILTER CHARACTERISTICS
−3 dB Bandwidth
1 dB Flatness
Out-of-Band Rejection
Differential Gain
92
7
5.5
40
9.7
8.0
50
0.25
0.10
40
MHz
MHz
dB
f = 27 MHz
Modulated 10 step ramp, sync tip at 0 V
Modulated 10 step ramp, sync tip at 0 V
%
Differential Phase
Degrees
mA
ns
Linear Output Current
Group Delay Variation
Signal-to-Noise Ratio
f = 100 kHz to 5 MHz
100% white signal, f = 100 kHz to 5 MHz
7
76
dB
VS = 5 V @ TA = 25°C, VIN = 1 V p-p, RL = 150 Ω, unless otherwise noted.
Table 2.
Parameter
Test Conditions/Comments
Min Typ
Max Unit
ELECTRICAL SPECIFICATIONS
Quiescent Supply Current
Quiescent Supply Current—Disabled
Supply Voltage
2.0
0.2
2.4
10
6
mA
μA
V
2.5
Input Voltage Range—Low/High
Input Resistance
Input Capacitance
Limited by output range; See the Applications section
0/2.35
10
1
0.5
V
MΩ
pF
μA
V
mV
dB
dB
dB
Input Bias Current
Output Voltage Range—Low/High
Output Offset Voltage
PSRR
0.10/4.80
100
61
6
145
Input referred
f = 1 MHz
50
5.85
Pass-Band Gain
Input-to-Output Isolation—Disabled
FILTER CHARACTERISTICS
−3 dB Bandwidth
1 dB Flatness
Out-of-Band Rejection
Differential Gain
92
7.2
5.5
40
9.5
7.9
50
0.25
0.15
40
MHz
MHz
dB
f = 27 MHz
Modulated 10 step ramp, sync tip at 0 V
Modulated 10 step ramp, sync tip at 0 V
%
Differential Phase
Degrees
mA
ns
Linear Output Current
Group Delay Variation
Signal-to-Noise Ratio
f = 100 kHz to 5 MHz
100% white signal, f = 100 kHz to 5 MHz
7.1
76
dB
Rev. A | Page 3 of 16
ADA4430-1
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter
Supply Voltage
Power Dissipation
Storage Temperature Range
Operating Temperature Range
Lead Temperature (Soldering 10 sec)
Junction Temperature
The power dissipated in the package (PD) is the sum of the
quiescent power dissipation and the power dissipated in the
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.
Rating
6 V
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.
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.
Figure 3 shows the maximum safe power dissipation in the
package vs. the ambient temperature for the 6-lead SC70
(430°C/W) on a JEDEC standard 4-layer board.
THERMAL RESISTANCE
θJA is specified for the worst-case conditions, that is, θJA is
specified for a device soldered in the circuit board.
0.50
0.45
0.40
0.35
0.30
0.25
0.20
0.15
0.10
0.05
0
Table 4. Thermal Resistance
Package Type
6-Lead SC70
θJA
Unit
430
°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.
–40
–20
0
20
40
60
80
100
120
AMBIENT TEMPERATURE (°C)
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.
Rev. A | Page 4 of 16
ADA4430-1
PIN CONFIGURATION AND FUNCTION DESCRIPTIONS
ADA4430-1
V
x1
V +
S
1
2
3
6
5
4
IN
2*R
2*R
GND
SAG
PD
R
2*R
V
OUT
Figure 4. 6-Lead SC70, Top View
Table 5. Pin Function Descriptions
Pin Number
Mnemonic
Description
Input Voltage.
Ground.
Feedback Connection.
Output Voltage.
1
2
3
4
5
6
VIN
GND
SAG
VOUT
PD
Power Down.
VS+
Positive Power Supply.
Rev. A | Page 5 of 16
ADA4430-1
TYPICAL PERFORMANCE CHARACTERISTICS
PD
VS = +3 V, RL, = 150 Ω, VOUT = 2.0 V p-p,
= high, VOUT connected directly to SAG, TA = 25°C, unless otherwise noted.
9
6
3
0
–3
–6
6.5
V
= 3V
S
6.0
V
= 3V
S
V
= 5V
S
V
= 5V
S
5.5
5.0
4.5
4.0
3.5
3.0
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
1
10
1
10
FREQUENCY (MHz)
100
FREQUENCY (MHz)
Figure 5. Frequency Response at Various Power Supplies
Figure 8. Frequency Response Flatness at Various Power Supplies
9
6
3
0
–3
6.5
R
= 75Ω
L
R
= 150Ω
L
6.0
5.5
5.0
4.5
4.0
3.5
3.0
R
= 75Ω
L
R
= 150Ω
L
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
1
10
FREQUENCY (MHz)
100
1
10
FREQUENCY (MHz)
Figure 6. Frequency Response at Various Loads
Figure 9. Frequency Response Flatness at Various Loads
9
6
3
0
–3
6.5
+125°C
+25°C
–40°C
+125°C
6.0
5.5
5.0
4.5
4.0
3.5
3.0
–6
–9
+25°C
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
–40°C
1
10
100
1
10
FREQUENCY (MHz)
FREQUENCY (MHz)
Figure 7. Frequency Response at Various Temperatures
Figure 10. Frequency Response Flatness at Various Temperatures
Rev. A | Page 6 of 16
ADA4430-1
9
6
3
0
–3
65
60
55
50
45
40
35
30
V
= 3V
S
2.0V p-p
–6
–9
–12
–15
–18
–21
–24
–27
–30
–33
–36
–39
–42
–45
–48
0.2V p-p
V
= 5V
S
1
10
FREQUENCY (MHz)
100
1
10
FREQUENCY (MHz)
100
Figure 11. Frequency Response at Various Output Amplitudes
Figure 14. Group Delay at Various Power Supplies
–50
–55
–60
0
–5
NOISE SPECTRUM (NTSC)
INPUT REFERRED
INPUT REFERRED
5V
BANDWIDTH 100kHz TO 5.0MHz
AMPLITUDE (0dB = 714mV p-p)
NOISE LEVEL = –76.8dB rms
–65
–70
–75
–80
–85
–90
–95
–100
–105
–110
–115
–120
–125
–130
–135
–140
–145
–150
–10
–15
–20
–25
–30
–35
–40
–45
–50
–55
–60
–65
3V
0
1
2
3
4
5
6
0.001
0.01
0.1
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
Figure 12. Input-Referred Noise Spectral Density
Figure 15. PSRR vs. Frequency at Various Power Supplies
–40
–50
10000
V
V
= 1V p-p
IN
V
= 0V
DISABLE
= 0V
DIS
OUTPUT REFERRED
–60
1000
100
10
–70
–80
–90
–100
–110
–120
–130
0.1
1
10
100
500
0.01
0.1
1
10
100
FREQUENCY (MHz)
FREQUENCY (MHz)
Figure 13. Input-to-Output Isolation—Disabled vs. Frequency
Figure 16. Disabled Output Impedance vs. Frequency
Rev. A | Page 7 of 16
ADA4430-1
3.0
2.5
2.0
1.5
1.0
0.5
0
3.00
2.75
2.50
2.25
2.00
1.75
1.50
1.25
1.00
0.75
0.50
0.25
0
3.0
INPUT × 2
OUTPUT
2.5
2.0
1.5
1.0
0.5
0
–0.5
–1.0
–1.5
–2.0
–2.5
–3.0
ERROR
50ns/DIV
100ns/DIV
Figure 17. Transient Response
Figure 20. Settling Time
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
3.5
3.0
2.5
2.0
1.5
1.0
0.5
0
DISABLE
DISABLE
OUTPUT
OUTPUT
1µs/DIV
–0.5
–0.5
500ns/DIV
Figure 18. Disable Assert Time
Figure 21. Disable Deassert Time
4.0
3.5
3.0
–0.10
–0.11
–0.12
–0.13
–0.14
–0.15
–0.16
–0.17
–0.18
–0.19
–0.20
OUTPUT
2 × INPUT
2.5
2.0
1.5
1.0
0.5
0
–0.5
–1.0
200ns/DIV
–40 –25 –10
5
20
35
50
65
80
95 110 125
TEMPERATURE (°C)
Figure 22. Output Swing Limits vs. Temperature
Figure 19. Overdrive Recovery
Rev. A | Page 8 of 16
ADA4430-1
1.85
1.80
1.75
1.70
1.65
400
300
200
100
0
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
0
ENABLED (V
= 3V)
DIS
+125°C
+25°C
–40°C
DISABLED (V
= 0V)
60
DIS
–40
–20
0
20
40
80
100
120
0
0.5
1.0
1.5
2.0
2.5
3.0
TEMPERATURE (°C)
DISABLE VOLTAGE (V)
Figure 23. Power Supply Current vs. Temperature
Figure 24. Power Supply Current vs. Disable Voltage at Various Temperatures
Rev. A | Page 9 of 16
ADA4430-1
TEST CIRCUITS
V
S+
0.1µF
ADA4430-1
6
5
0.5V
V
PD
S+
TEST GENERATOR
R
= 150Ω
86.6Ω
L
1
V
TEST RECEIVER
IN
×1
V
118Ω
OUT
4
50Ω
50Ω
GND
2.6kΩ
2
50Ω
1.3kΩ
2.6kΩ
2.6kΩ
3 SAG
Figure 25. Test Circuit Used for Frequency Sweeps and Time-Domain Tests
V
S+
0.1µF
ADA4430-1
6
5
V
PD
S+
1.0V
150Ω
TEST GENERATOR
R
= 150Ω
L
220µF
1
V
TEST RECEIVER
IN
×1
V
75Ω
OUT
4
75Ω
150Ω
2 GND
2.6kΩ
75Ω
1.3kΩ
2.6kΩ
2.6kΩ
3 SAG
Figure 26. Test Circuit Used for Differential Gain, Differential Phase, and Noise Tests
Rev. A | Page 10 of 16
ADA4430-1
THEORY OF OPERATION
OVERVIEW
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 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
would normally indicate a single op amp with a 2- or 3-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 shutdown to draw less than 1 μA of supply
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 kꢀ. 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
PD
current using the power-down pin, ( ). Additionally, the
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 full-
scale 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 full-
scale 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.
ADA4430-1 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 minimum stop-band rejection of 42 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.
3V
VIDEO
DAC/
ENCODER
75Ω
75Ω
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 ground-
referenced 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
75Ω
VIDEO
DAC/
ENCODER
ADA4430-1
FILTER
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 large-
valued load resistor. Using a large-valued load resistor does not
interfere with the frequency response of the ADA4430-1.
R
G = +2
L
75Ω
Figure 28. DAC Driving Video Cable Using the ADA4430-1
Rev. A | Page 11 of 16
ADA4430-1
APPLICATIONS
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 single-
supply current-output DAC on its input and its output ac- and
dc-coupled.
3V
0.1µF
6
POWER-DOWN CONTROL
ADA4430-1
5
V
PD
S+
V
1
VIDEO
DAC/ENCODER
IN
47µF
×1
75Ω
V
4
OUT
VIDEO OUT
R
L
2 GND
3 SAG
2.6kΩ
2.6kΩ
1.3kΩ
2.6kΩ
22µF
Figure 29. AC-Coupled Output with SAG Correction
3V
0.1µF
POWER-DOWN CONTROL
ADA4430-1
5
6
V
PD
S+
V
VIDEO
DAC/ENCODER
1
IN
220µF
×1
75Ω
V
4
OUT
VIDEO OUT
R
L
2 GND
3 SAG
2.6kΩ
1.3kΩ
2.6kΩ
2.6kΩ
Figure 30. Traditional AC-Coupled Output with 220 μF Coupling Capacitor
3V
0.1µF
POWER-DOWN CONTROL
ADA4430-1
5
6
V
PD
S+
V
VIDEO
DAC/ENCODER
1
IN
×1
75Ω
V
4
OUT
VIDEO OUT
R
L
2 GND
3 SAG
2.6kΩ
1.3kΩ
2.6kΩ
2.6kΩ
Figure 31. DC-Coupled Output
Rev. A | Page 12 of 16
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 in the
neighborhood of 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 high-
pass response. Figure 32 illustrates the SAG frequency response
immediately at the ADA4430-1 output and at the load side of the
47 μF capacitor.
V
IN (max) = (VOM − VOO)/2
where:
V
V
V
IN (max) is the upper end of the usable input voltage range.
OM is the maximum output swing.
OO is the output-referred offset voltage.
12
10
8
6
4
2
0
–2
–4
–6
–8
AT ADA4430-1 OUTPUT
AT LOAD SIDE OF 47µF CAPACITOR
–10
1
10
100
1000
10000
100000
FREQUENCY (Hz)
Figure 32. SAG Corrected Frequency Response at ADA4430-1 Output and
at the Load Side of the 47 μF Capacitor
Rev. A | Page 13 of 16
ADA4430-1
RECONSTRUCTION FILTER APPLICATIONS
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 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.
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 is 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
POWER-DOWN CONTROL
0.1µF
ADA4430-1
6
5
0.1µF
V
PD
S+
17, 25, 29, 38, 43, 54, 63
V
AA
1
V
IN
ADV7190/ADV7191
DAC
75Ω CABLE
×1
V
75Ω
OUT
4
R
AGND
600Ω
SET
48
GND
2
2.6kΩ
2.6kΩ
75Ω
18, 24, 26, 33,
39, 42, 55, 64
2.4kΩ
1.3kΩ
2.6kΩ
3 SAG
Figure 33. Using the ADA4430-1 with the ADV7190/ADV7191 Video Encoder
3V
POWER-DOWN CONTROL
0.1µF
ADA4430-1
6
5
0.1µF
PD
V
S+
2, 10, 18, 25, 27
V
AA
1
V
IN
75Ω CABLE
ADV7174 DAC
SET
×1
V
75Ω
OUT
4
R
AGND
262.5Ω
(191Ω + 71.5Ω)
31
2.6kΩ
2.6kΩ
2 GND
3 SAG
75Ω
6-9, 11, 12,
17, 19, 26, 40
1.3kΩ
2.6kΩ
1041Ω
(931Ω + 110Ω)
Figure 34. Using the ADA4430-1 with the ADV7174 Video Encoder
Rev. A | Page 14 of 16
ADA4430-1
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.
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.
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. A | Page 15 of 16
ADA4430-1
OUTLINE DIMENSIONS
2.20
2.00
1.80
2.40
2.10
1.80
6
1
5
2
4
3
1.35
1.25
1.15
PIN 1
1.30 BSC
0.65 BSC
1.00
0.90
0.70
0.40
0.10
1.10
0.80
0.46
0.36
0.26
0.30
0.15
0.22
0.08
0.10 MAX
SEATING
PLANE
0.10 COPLANARITY
COMPLIANT TO JEDEC STANDARDS MO-203-AB
Figure 35. 6-Lead Thin Shrink Small Outline Transistor Package [SC70]
(KS-6)
Dimensions shown in millimeters
ORDERING GUIDE
Model
ADA4430-1YKSZ_R21
ADA4430-1YKSZ-R71
ADA4430-1YKSZ-RL1
Temperature Range
Package Description
6-Lead SC70
6-Lead SC70
Package Option
Branding
H0G
H0G
Ordering Quantity
−40°C to +125°C
−40°C to +125°C
−40°C to +125°C
KS-6
KS-6
KS-6
250
3,000
10,000
6-Lead SC70
H0G
1 Z = Pb-free part.
©2006 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
D05885-0-6/06(A)
Rev. A | Page 16 of 16
相关型号：
ADA4430-1YKSZ-RL
SPECIALTY CONSUMER CIRCUIT, PDSO6, ROHS COMPLIANT, MO-203AB, SC-70, 6 PIN
ROCHESTER
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