ADA4424-6

Rev. C | Page 12 of 16

Fixed Offset Cancellation Mode

In addition to the automatic mode, there are two levels of fixed

offset correction available. In high offset mode, fixed voltages of

1.0 V and 1.1 V are subtracted from the Y_IN and HY_IN inputs,

respectively. In low offset mode, a fixed voltage of 0.33 V is

subtracted from both Y_IN and HY_IN. The various modes of

offset cancellation are outlined in Table 6.

Table 6. Offset Cancellation Mode Selection

MODE1

(Pin 23)

MODE0

(Pin 16)

Output Offset Cancellation

Low (0)

Low (0)

Auto-cancel, sync-tip sampling mode.

Clamps the input referred SD sync tip

to −214 mV, and the input referred

ED/HD sync tip to −300 mV.

Low (0)

High (1)

Auto-cancel, back porch sampling

mode. Sets the output blanking level

to 0 V, independent of sync depth.

High (1)

Low (0)

Fixed cancellation mode, high dc

offset.

Subtracts 1.0 V from the Y_IN signal;

subtracts 1.1 V from the HY_IN signal.

High (1)

High (1)

Fixed cancellation mode, low dc offset.

Subtracts 0.33 V from both the Y_IN

and HY_IN signals.

Offset Cancellation Disable

The offset cancellation function can be enabled or disabled via

the OFFSET_ENB pin, as described in Table 7.

Table 7. Offset Cancellation Enable/Disable

OFFSET_ENB

(Pin 17)

Offset Cancellation State

Low (0)

Offset cancellation is disabled.

High (1)

Offset cancellation is enabled. Function is

determined by the MODE1 and MODE0 pins

(see Table 6).

D-TERMINAL AND S-TERMINAL SUPPORT

Full D-terminal support (EIAJ RC-5237 D5) is provided for the

component channels (HY_OUT, HPb_OUT, HPr_OUT). Level

D1 through Level D5 are supported for vertical resolution, scan

type, and aspect ratio selection. Details are shown in Table 8,

Table 9, and Table 10.

S-terminal (also known as S_DC or S1/S2) support for S-video

aspect ratio selection is also provided, as described in Table 11.

The VDD5 pin (Pin 38) provides 5 V power for these outputs.

If D- or S-terminal support is not required, it is recommended

that Pin 2 to Pin 5 and Pin 34 to Pin 38 remain unconnected.

Table 8. D-Terminal Control for Vertical Resolution Selection

Input Logic

Level D1 (Pin 2)

Nominal Output (V)

L1_OUT (Pin 37)

RL = 100 kΩ

Vertical Resolution

(Number of Lines)

Low (0)

0.0

480

Mid or open

2.1

720

High (1)

4.5

1080

Table 9. D-Terminal Control for Scan Selection

Input Logic Level

D2 (Pin 3)

Nominal Output (V)

L2_OUT (Pin 36)

RL = 100 kΩ

Scan Type

Low (0)

0.0

Interlaced

Mid or open

2.1

N/A

High (1)

4.5

Progressive

Table 10. D-Terminal Control for Aspect Ratio Selection

Input Logic Level

D3 (Pin 4)

Nominal Output (V)

L3_OUT (Pin 35)

RL = 100 kΩ

Aspect Ratio

Low (0)

0.0

4:3

Mid or open

2.1

4:3 letterbox

High (1)

4.5

16:9

Table 11. S-Terminal Control for Aspect Ratio Selection

Input Logic Level

S (Pin 5)

Nominal Output (V)

S1/S2_OUT (Pin 34)

RL = 100 kΩ

Aspect Ratio

Low (0)

0.0

4:3

Mid or open

2.1

4:3 letterbox

High (1)

4.5

16:9