INPUT SELECT

AUTO/MANUAL

DETECT SELECT

SD/HD SELECT*

POWER SAVE

GND

GND

Yc

Y

GND

COLOR

DECODER

SYNC

PROCESSOR

1

2

12

11

10

9

8

7

6

5

4

3

24

23

22

21

20

19

18

17

16

15

14

13

LMH1251

SNLS193J – AUGUST 2005 – REVISED MARCH 2013

www.ti.com

Connection Diagram

Figure 1. 24-Pin TSSOP - Top View

See PW Package

Truth Table-Input Select

Pin 24

OUT

0

RGBHV input Ch

1

Truth Table- Format/Conversion Select

Pin 23

Pin 22

SYNC

Format Detection

Conversion Scheme

0

0

Bi-Level

Manual

480i/480p

0

1

Tri-Level

Manual

720p/1080i

1

Bi-Level

Auto

480i/480p

1

Tri-Level

Auto

720p/1080i

(1)

When Pin 23 is set high, the LMH1251 is in Auto Mode, in which it can detect the incoming video format (SD or HD) and apply the

appropriate color conversion and sync processing. With Auto Mode, Pin 22 becomes an output pin, and will either output a logic high or

low to notify the user of the format that is being detected by the LMH1251. If Pin 23 is set low, the LMH1251 is in Manual Mode, in

which the user must specify the format with Pin 22. With Manual Mode, Pin 22 is an input pin. Since Pin 22 is a bi-directional pin, care

must be given not to apply any voltages to it when it is in the Auto Mode, in which it functions as an output pin. The use of the Auto

Mode with Pin 22 left floating is typically recommended.

Truth Table-Power Save

Pin 21

Low Power Mode

0

Disable

1

Enabled

2

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