Data Sheet

ADA4830-1/ADA4830-2

Rev. C | Page 19 of 22

−

+

ADV7180

INN

VOUT

GND

INP

ADA4830-1

75

Ω

+

STB

ENA

+VS

4.7µF

0.1µF

0.1µF

21

25

24

23

19

20

13

11

32

1

31

4

12

26

28

17

82nF

10nF

ELPF

27

ALSB

SCLK

SCLK

SDA

SDATA

XTAL1

XTAL

0.1µF

+VS

ENABLE

(INPUT)

STB FLAG

(OUTPUT)

2.2µF

0.1µF

5k

Ω

(2.9V TO 5.5V)

VREF

0.1µF

10nF

0.1µF

10nF

0.1µF

10nF

0.1µF

10nF

KEEP VREFN AND VREFP CAPACITORS AS CLOSE AS

POSSIBLE TO THE ADV7180 AND ON THE SAME SIDE

OF THE PCB AS THE ADV7180.

LOCATE CLOSE TO, AND

ON THE SAME SIDE AS,

THE ADV7180

ALSB TIED HI

ALSB TIED LOW

RESET

RESET

P0

P1

P2

P3

P4

P5

P6

P7

P0

YCrCb

8-BIT

656 DATA

P[0:7]

P1

P2

P3

P4

P5

P6

P7

16

15

10

9

8

7

6

5

VREFN

VREFP

28.63636MHz

47pF

47pF

1M

Ω

4k

Ω

LLC

1.69k

Ω

INTRQ

SFL

VS/FIELD

EXTERNAL

LOOP FILTER

KEEP CLOSE TO THE ADV7180 AND ON

THE SAME SIDE OF PCB AS THE ADV7180.

HS

LLC

INTRQ

SFL

VS/FIELD

HS

×1

Figure 41. ADA4830-1 Driving an ADV7180 Video Decoder

The ADA4830-1 and ADA4830-2 are differential receivers whose

overall performance is independent of the transmitter IC used

and whether the transmission line is ac-coupled or dc-coupled.

The ADA4830-1 and ADA4830-2 are specifically designed to

perform as differential line receivers. The circuit in Figure 41

shows a detailed schematic of the ADA4830-1 and the ADV7180

configured for this function. The signal is received differentially

relative to the common of the source circuitry, and that voltage

is exactly reproduced with an attenuating gain of 0.50 V/V. This

is designed to keep the video signal within the allowed range of

the video decoder, which is typically 1 V p-p or less.

The common-mode rejection vs. frequency, shown in Figure 14,

typically 65 dB at low frequencies, enables the recovery of video

signals in the presence of large common-mode noise. The high

input impedance permits the ADA4830-1 and ADA4830-2 to

operate as a bridging amplifier across low impedance terminations

with negligible loading.