ANALOG DEVICES ADA4430-1 Service Manual

Ultralow Power Video Filter

www.BDTIC.com/ADI

FEATURES

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 typ
Low quiescent current: 1.85 mA typ
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 @ 1 MHz
Low input bias current: 0.5 μA
Small packaging: SC70
Wide operating temperature range: −40°C to +125°C

APPLICATIONS

Portable media players
Portable gaming consoles
Cell phones
Digital still cameras
Portable DVD players
Portable video cameras

with Power-Down

ADA4430-1

PIN CONFIGURATION

ADA4430-1

V

IN

GND

SAG

6.5

6.0

5.5

5.0

4.5

GAIN (dB)

4.0

3.5

3.0
11

Figure 2. Frequency Response Fla

x1

1

2*R

2

R

2*R

3

2*R

Figure 1.

VS = 5V

FREQUENCY (MHz)

tness at Various Power Supplies

+

V

6

S

5

PD

4

V

OUT

05885-001

VS = 3V

05885-006

0

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

h as 6 V while providing the dynamic range required by

as hig
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 Anal og Devices for its use, nor for any infringements of patents or ot her
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.

The ADA4430-1 also provides an on-chip dc offset to avoid
c

lipping 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
r

ated to work in the extended automotive temperature range of

−40°C to +125°C.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] www.analog.com
Fax: [phone] ©2006 Analog Devices, Inc. All rights reserved.

ADA4430-1

www.BDTIC.com/ADI

TABLE OF CONTENTS

Features .............................................................................................. 1

Theory of Operation ...................................................................... 11

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 Cir c ui t s .....................................................................................10

REVISION HISTORY

6/06—Rev. 0 to Rev. A

Changes to Figure 1.......................................................................... 1

Changes to Figure 4.......................................................................... 5

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

3/06—Revision 0: Initial Version

Rev. A | Page 2 of 16

ADA4430-1

www.BDTIC.com/ADI

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 1.85 2.3 mA
Quiescent Supply Current—Disabled 0.1 5 μA
Supply Voltage 2.5 6 V
Input Voltage Range—Low/High Limited by output range; see the Applications section 0/1.38 V
Input Resistance 10 MΩ
Input Capacitance 1 pF
Input Bias Current 0.5 μA
Output Voltage Range—Low/High 0.10/2.85 V
Output Offset Voltage 95 140 mV
PSRR Input referred 50 60 dB
Pass-Band Gain 5.85 6 dB
Input-to-Output Isolation—Disabled f = 1 MHz 92 dB

FILTER CHARACTERISTICS

−3 dB Bandwidth 7 9.7 MHz
1 dB Flatness 5.5 8.0 MHz
Out-of-Band Rejection f = 27 MHz 40 50 dB
Differential Gain Modulated 10 step ramp, sync tip at 0 V 0.25 %
Differential Phase Modulated 10 step ramp, sync tip at 0 V 0.10 Degrees
Linear Output Current 40 mA
Group Delay Variation f = 100 kHz to 5 MHz 7 ns
Signal-to-Noise Ratio 100% white signal, f = 100 kHz to 5 MHz 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 2.0 2.4 mA
Quiescent Supply Current—Disabled 0.2 10 μA
Supply Voltage 2.5 6 V
Input Voltage Range—Low/High Limited by output range; See the Applications section 0/2.35 V
Input Resistance 10 MΩ
Input Capacitance 1 pF
Input Bias Current 0.5 μA
Output Voltage Range—Low/High 0.10/4.80 V
Output Offset Voltage 100 145 mV
PSRR Input referred 50 61 dB
Pass-Band Gain 5.85 6 dB
Input-to-Output Isolation—Disabled f = 1 MHz 92 dB

FILTER CHARACTERISTICS

−3 dB Bandwidth 7.2 9.5 MHz
1 dB Flatness 5.5 7.9 MHz
Out-of-Band Rejection f = 27 MHz 40 50 dB
Differential Gain Modulated 10 step ramp, sync tip at 0 V 0.25 %
Differential Phase Modulated 10 step ramp, sync tip at 0 V 0.15 Degrees
Linear Output Current 40 mA
Group Delay Variation f = 100 kHz to 5 MHz 7.1 ns
Signal-to-Noise Ratio 100% white signal, f = 100 kHz to 5 MHz 76 dB

Rev. A | Page 3 of 16

ADA4430-1

www.BDTIC.com/ADI

ABSOLUTE MAXIMUM RATINGS

Table 3.

Parameter Rating

Supply Voltage 6 V
Power Dissipation See Figure 3
Storage Temperature Range –65°C to +125°C
Operating Temperature Range –40°C to +125°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 a device soldered in the circuit board.

Table 4. Thermal Resistance

Package Type θ

6-Lead SC70 430 °C/W

JA

Maximum Power Dissipation

The maximum safe power dissipation in the ADA4430-1
package is limited by the associated rise in junction temperature
(T

) on the die. At approximately 150°C, which is the glass

J

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

Unit

The power dissipated in the package (P
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 (V
current (I

). The power dissipated due to the load drive depends

S

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.

Airflow increases heat dissipation, effectively reducing θ
addition, more metal directly in contact with the package leads
from metal traces, through-holes, ground, and power planes
reduces the θ

.

JA

Figure 3 shows the maximum safe power dissipation in the
p

ackage vs. the ambient temperature for the 6-lead SC70

(430°C/W) on a JEDEC standard 4-layer board.

0.50

0.45

0.40

0.35

0.30

0.25

0.20

0.15

0.10

MAXIMUM POWER DISSIPATION (W)

0.05

0

–40 120100806040020–20

Figure 3. Maximum Power Dissipation vs. Temperature for a 4-Layer Board

result in changes in the silicon devices potentially causing
failure.

AMBIENT TEMP ERATURE (°C)

) is the sum of the

D

) times the quiescent

S

JA

. In

05885-002

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

www.BDTIC.com/ADI

PIN CONFIGURATION AND FUNCTION DESCRIPTIONS

ADA4430-1

V

IN

x1

1

+

V

6

S

GND

SAG

2*R

2

R

2*R

3

Figure 4. 6-Lead SC70, Top View

2*R

5

PD

4

V

OUT

05885-041

Table 5. Pin Function Descriptions

Pin Number Mnemonic Description

1 V

IN

Input Voltage.
2 GND Ground.
3 SAG Feedback Connection.
4 V
5

6 V

OUT

PD

S+

Output Voltage.

Power Down.

Positive Power Supply.

Rev. A | Page 5 of 16

ADA4430-1

www.BDTIC.com/ADI

TYPICAL PERFORMANCE CHARACTERISTICS

VS = +3 V, RL, = 150 Ω, V

9
6
3

0
–3
–6
–9

–12
–15
–18
–21
–24

GAIN (dB)

–27
–30
–33
–36
–39
–42
–45
–48

–3
–6
–9

–12
–15
–18
–21
–24

GAIN (dB)

–27
–30
–33
–36
–39
–42
–45
–48

–3
–6
–9

–12
–15
–18
–21
–24

GAIN (dB)

–27
–30
–33
–36
–39
–42
–45
–48

11

Figure 5. Frequency Response at Various Power Supplies

9

6

3

0

11

Figure 6. Frequency Response at Various Loads

9

6

3

0

11

Figure 7. Frequency Response at Various Temperatures

= 2.0 V p-p, PD = high, V

OUT

VS = 3V

V

= 5V

S

FREQUENCY (MHz)

RL = 75Ω

FREQUENCY (MHz)

RL = 150Ω

FREQUENCY (MHz)

connected directly to SAG, TA = 25°C, unless otherwise noted.

OUT

6.5

6.0

5.5

5.0

4.5

GAIN (dB)

4.0

3.5

05885-003

0010

3.0
110

Figure 8. Frequency Response Fla

FREQUENCY (MHz)

tness at Various Power Supplies

6.5

6.0

5.5

5.0

4.5

GAIN (dB)

4.0

3.5

05885-004

0010

3.0
110

FREQUENCY (MHz)

Figure 9. Frequency Response Flatness at Various Loads

+125°C
+25°C
–40°C

05885-005

0010

6.5

6.0

5.5

5.0

4.5

GAIN (dB)

4.0

3.5

3.0
110

FREQUENCY (MHz)

Figure 10. Frequency Response Flatness at Various Temperatures

VS = 5V

VS = 3V

05885-006

RL = 75Ω

RL = 150Ω

05885-007

+125°C

+25°C

–40°C

05885-008

Rev. A | Page 6 of 16

ADA4430-1

–

–

www.BDTIC.com/ADI

9
6
3

0
–3
–6
–9

–12
–15
–18
–21
–24

GAIN (dB)

–27
–30
–33
–36
–39
–42
–45
–48

11

2.0V p-p

0.2V p-p

10

FREQUENCY (MHz)

Figure 11. Frequency Response at Various Output Amplitudes

50

NOISE SPECTRUM (NTSC)

–55

INPUT REFERRED

–60

BANDWIDTH 100kHz TO 5.0MHz

–65

AMPLI TUDE (0d B = 714mV p-p)

–70

NOISE L EVEL = –76.8dB rms

–75
–80
–85
–90
–95

–100

(dB)

–105
–110
–115
–120
–125
–130
–135
–140
–145
–150

1065432

FREQUENCY (MHz)

Figure 12. Input-Referred Noise Spectral Density

40

VIN = 1V p-p
V

= 0V

DIS

–50

OUTPUT REFERRED

–60

–70

–80

–90

ISOLATION (dB)

–100

–110

–120

–130

0.01 1001010.1

Figure 13. Input-to-Output Isolatio

FREQUENCY (MHz)

n—Disabled vs. Frequency

05885-009

00

05885-010

05885-011

65

60

55

50

45

GROUP DELAY (ns)

40

35

30

110010

VS = 5V

FREQUENCY (MHz)

VS = 3V

Figure 14. Group Delay at Various Power Supplies

0

INPUT REFERRED

–5

–10

–15

–20

–25

–30

–35

PSRR (dB)

–40

–45

–50

–55

–60

–65

0.001 0.01 1001010.1

FREQUENCY (MHz)

3V

Figure 15. PSRR vs. Frequency at Various Power Supplies

10000

V

DISABLE

1000

IMPEDANCE (Ω)

100

10

0.1 1 10 100 500

Figure 16. Disabled Output Imped

FREQUENCY (MHz)

ance vs. Frequency

05885-012

5V

05885-013

=0V

05885-030

Rev. A | Page 7 of 16

ADA4430-1

–

www.BDTIC.com/ADI

3.0

2.5

2.0

1.5

1.0

OUTPUT VOLTAGE (V)

0.5

100ns/DIV

0

05885-015

3.00

2.75

2.50

2.25

2.00

1.75

1.50

1.25

1.00

OUTPUT VOLTAGE (V)

0.75

0.50

0.25

0

INPUT × 2

OUTPUT

ERROR

50ns/DIV

3.0

2.5

2.0

1.5

1.0

0.5

0

–0.5

–1.0

–1.5

–2.0

–2.5

–3.0

ERROR (%)

05885-018

Figure 17. Transient Response

3.5

3.0

2.5

2.0

1.5

1.0

OUTPUT VOLTAGE (V)

0.5

0

–0.5

DISABLEDISABLE

OUTPUT

1µs/DIV

05885-016

3.5

3.0

2.5

2.0

1.5

1.0

OUTPUT VOLTAGE (V)

0.5

0

–0.5

Figure 18. Disable Assert Time

4.0

3.5

3.0

2.5

2.0

1.5

1.0

OUTPUT (V)

0.5

0

–0.5

–1.0

OUTPUT
2× INPUT

200ns/DIV

05885-033

Figure 19. Overdrive Recovery

0.10

–0.11

(V)

–0.12

OUT

–0.13

AND V

S

–0.14

–0.15

–0.16

–0.17

–0.18

–0.19

DIFFERENCE BETWEEN V

–0.20

–40 –25 –10 5 20 35 50 65 80 95 110 125

Figure 22. Output Swing Li

Figure 20. Settling Time

DISABLE

OUTPUT

500ns/DIV

Figure 21. Disable Deassert Time

TEMPERATURE (°C)

mits vs. Temperature

05885-019

05885-031

Rev. A | Page 8 of 16

ADA4430-1

www.BDTIC.com/ADI

1.85

ENABLED (V

1.80

1.75

1.70

POWER SUPPLY CURRENT–ENABL ED (mA)

1.65

= 3V)

DIS

DISABLED (V

TEMPERATURE ( °C)

DIS

= 0V)

Figure 23. Power Supply Current vs. Temperature

400

300

200

100

POWER SUPPLY CURRENT–DIS ABLED (nA)

05885-021

0

120100806040200–20–40

2.0

1.8

1.6
+125°C

1.4

1.2

1.0

0.8

0.6

0.4

POWER SUPPL Y CURRENT (mA)

0.2

+25°C

0

–40°C

DISABLE VOLTAGE (V)

05885-022

3.02.52.01.51.00.50

Figure 24. Power Supply Current vs. Disable Voltage at Various Temperatures

Rev. A | Page 9 of 16

ADA4430-1

V

R

V

www.BDTIC.com/ADI

TEST CIRCUITS

S+

0.1µF

50Ω

1

2

3

ADA4430-1

V

IN

×1

GND

SAG

2.6kΩ

2.6kΩ

0.5V

TEST GENERATOR

50Ω

Figure 25. Test Circuit Used for Frequency Sweeps and T

ADA4430-1

TEST GE NERATO

75Ω

220µF

1.0V

150Ω

150Ω

1

V

IN

×1

GND

2

3

SAG

2.6kΩ

2.6kΩ

PD

1.3kΩ

PD

1.3kΩ

5

5

6

V

V

2.6kΩ

S+

6

V

V

2.6kΩ

S+

OUT

S+

OUT

= 150Ω

R

L

118Ω

4

ime-Domain Tests

0.1µF

R

= 150Ω

L

75Ω

4

TEST RECEIVER

50Ω86.6Ω

TEST RECEIVER

75Ω

05885-038

Figure 26. Test Circuit Used for Differential Ga

in, Differential Phase, and Noise Tests

05885-039

Rev. A | Page 10 of 16

ADA4430-1

V

V

www.BDTIC.com/ADI

THEORY OF OPERATION

OVERVIEW

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
current using the power-down pin, (
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

z and a minimum stop-band rejection of 42 dB at

5.5 MH
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
b

oth 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) a

nd 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.

PD

). Additionally, the

The internal buffer at the ADA4430-1 input isolates the source
r

esistance 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

nnected internally to the GND pin and has a nominal impedance

co
of 5.2 k. 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.

irectly. Properly terminating the line results in the DAC driving

d
two 75 Ω loads and requires in excess of 30 mA to reach a full­scale level of 1.3 V.

iven using the ADA4430-1 and a series-shunt termination. This

dr
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
f

iltering 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.

Figure 27 shows a video DAC driving a cable

Figure 28 shows the same video load being

Figure 27. The high level of

3

VIDEO

DAC/

ENCODER

75Ω

75Ω

The input range of the ADA4430-1 includes ground, while the

utput range is limited by the saturation of the output devices.

o
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.

The high input impedance and low input capacitance of the
AD

A4430-1 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.

Rev. A | Page 11 of 16

Figure 27. DAC Driving Video Cable Directly

3

0.1µF

VIDEO

DAC/

ENCODER

Figure 28. DAC Driving Video Cable Using the ADA4430-1

ADA4430-1

R

L

FILTER
G = +2

75Ω

05885-034

75Ω

05885-035

ADA4430-1

V

V

V

T

V

www.BDTIC.com/ADI

APPLICATIONS

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
n

umber of ways the ADA4430-1 can be used with a single­supply current-output DAC on its input and its output ac- and
dc-coupled.

SAG correction allows the use of two small, lower cost
ca

pacitors 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.

3

56

V

S+

V

0.1µF

OUT

47µF

4

75Ω

VIDEO OUT

05885-027

POWER-DOW N CONTROL

VIDEO

DAC/ENCODER

ADA4430-1

PD

V

1

IN

×1

R

L

2

GND

3

SAG

2.6kΩ

2.6kΩ

22µF

1.3kΩ

2.6kΩ

Figure 29. AC-Coupled Output with SAG Correction

3

POWER-DOWN CONTROL

VIDEO

DAC/ENCODER

Figure 30. Traditional AC-Coupled Output with 2

ADA4430-1

V

1

IN

R

L

2

GND

3

SAG

56

PD

×1

2.6kΩ

1.3kΩ

2.6kΩ

2.6kΩ

0.1µF

V

S+

220µF

V

4

OUT

75Ω

20 μF Coupling Capacitor

VIDEO OUT

5885-028

3

POWER-DOWN CONTROL

ADA4430-1

VIDEO

DAC/ENCODER

V

1

IN

×1

R

L

2

GND

3

SAG

2.6kΩ

2.6kΩ

Figure 31. DC-Coupled Output

Rev. A | Page 12 of 16

1.3kΩ

56

PD

2.6kΩ

0.1µF

V

S+

V

OUT

75Ω

4

IDEO OU

05885-029

ADA4430-1

www.BDTIC.com/ADI

USABLE INPUT VOLTAGE RANGE

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

V

(max) = (VOM − VOO)/2

IN

where:

(max) is the upper end of the usable input voltage range.

V

IN

is the maximum output swing.

V

OM

is the output-referred offset voltage.

V

OO

SAG CORRECTION FREQUENCY RESPONSE

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
a

nd 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 high­pass response.

ediately at the ADA4430-1 output and at the load side of the

imm

Figure 32 illustrates the SAG frequency response

47 µF capacitor.

12

10

8

6

4

2

0

GAIN (dB)

–2

–4

–6

–8

–10

1 10 100 1000 10000010000

Figure 32. SAG Corrected Frequency Response at ADA4430-1 Output and

at

the Load Side of the 47 μF Capacitor

AT ADA4430-1 OUTP UT
AT LOAD SI DE OF 47µF CAPACITOR

FREQUENCY (Hz)

Figure 29)

05885-040

Rev. A | Page 13 of 16

ADA4430-1

V

V

www.BDTIC.com/ADI

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/

AD

V7191 output DAC is shown for illustrative purposes, and

t

he remaining portions of the ADV7190/ADV7191 are omitted.

The ADV7190/ADV7191 is op

The 2.4 kΩ resistor, R

SET

erated in 4× oversampling mode.

, 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 illustrates another reconstruction filter application,
fol

lowing the ADV7174 video encoder. As in Figure 33, one

ADV7174 output DAC is shown for illustrative purposes, and

t

he remaining portions of the ADV7174 are omitted.

The 1041 Ω resistor, R

, shown in Figure 34, sets the DAC

SET

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
c

urrent of approximately 35 mA and is therefore capable of
driving the video cable directly; however, as is shown in Figure 34,
th

e ADA4430-1 offers a lower, power cable-driving option.

Figure 34 reveals the details of how the ADA4430-1 saves

wer when driving video cables with terminations at both

po
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

, but the current driven into the cable is 35 mA − twice

1.313 V

Figure 27, the output voltage is

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.

3

POWER-DOWN CONTROL

17, 25,29, 38,43, 54, 63

V

AA

ADV7190/ADV7191

DAC

R

SET

48

2.4kΩ

AGND

18, 24,26, 33,
39, 42,55, 64

0.1µF

600Ω

ADA4430-1

1

V

IN

×1

GND

2

3

SAG

2.6kΩ

2.6kΩ

PD

1.3kΩ

5

6

V

V

2.6kΩ

S+

OUT

0.1µF

4

75Ω

75Ω CABLE

75Ω

05885-036

Figure 33. Using the ADA4430-1 with the ADV7190/ADV7191 Video Encoder

3

POWER-DOWN CONTROL

0.1µF

2, 10, 18, 25, 27

V

AA

ADV7174 DAC

R

SET

31

1041Ω
(931Ω + 110Ω)

ADA4430-1

0.1µF

1

V

IN

AGND

(191Ω + 71.5Ω)

6-9, 11, 12,
17, 19, 26, 40

262.5Ω

×1

GND

2

3

SAG

2.6kΩ

2.6kΩ 2.6kΩ

Figure 34. Using the ADA4430-1 with the ADV7174 Video Encoder

PD

1.3kΩ

6

5

V

S+

V

OUT

4

75Ω

75Ω CABLE

75Ω

05885-037

Rev. A | Page 14 of 16

ADA4430-1

www.BDTIC.com/ADI

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
tra

ce 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.

When the ADA4430-1 receives its inputs from a device with
c

urrent 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.

Rev. A | Page 15 of 16

ADA4430-1

www.BDTIC.com/ADI

OUTLINE DIMENSIONS

2.20

2.00

1.80

2.40

1.35

1.25

1.15

PIN 1

1.30 BSC

1.00

0.90

0.70

0.10 MAX

0.10 COPLANARITY

COMPLIANT TO JEDEC STANDARDS MO-203-AB

Figure 35. 6-Lead Thin Shrink Small Outline Transistor Package [SC70]

4 5 6

2.10

3 2 1

1.80

0.65 BSC

0.40

0.10

0.22

0.08

0.30

0.15

1.10

0.80

SEATING
PLANE

(K

S-6)

Dimensions shown in millimeters

0.46

0.36

0.26

ORDERING GUIDE

Model Temperature Range Package Description Package Option Branding Ordering Quantity

ADA4430-1YKSZ_R2
ADA4430-1YKSZ-R7
ADA4430-1YKSZ-RL

1

Z = Pb-free part.

1

−40°C to +125°C 6-Lead SC70 KS-6 H0G 250

1

−40°C to +125°C 6-Lead SC70 KS-6 H0G 3,000

1

−40°C to +125°C 6-Lead SC70 KS-6 H0G 10,000

©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