CSOUT

HSOUT

BPOUT

VSOUT

OEOUT

COLOR

BURST

START OF FIELD 1

ODD FIELD

LINE #

1

3

4

5

6

7

9

10

11

525

2

8

3H

H

3H

3H

H

½ H

VERTICAL SYNC

SERRATION

TP2

Odd/Even

Field Output

2

1

TP3

Burst/Back

Porch Output

2

1

TP4

Composite

Sync Output

2

1

TP5

Vertical Sync

Output

2

1

TP6

Horizontal

Sync Output

2

1

100:

100:

100:

100:

100:

7

6

8

9

10

OEOUT

BPOUT

CSOUT

VSOUT

HSOUT

LMH1980

4

5

3

2

1

GND

HD

U2

10 k:

1%

0.1 PF

0.1 PF

10 PF

10 k:

100:

TP1

HD Detect Flag Output

2

1

J2

GND

TP7

GND

1

1

J1

TP8

1

1

100:

560 pF

*OPT

Q1

MMBT3904

75:

BNC

J3

LMH1980

www.ti.com

SNLS263A – JULY 2007 – REVISED MARCH 2013

LMH1980 Test Circuit

Figure 2. Test Circuit

The LMH1980 test circuit is shown in Figure 2. The video generator should provide a clean, low-noise video input

signal with minimal sync pulse overshoot over 75

Ω coaxial cable, which should be impedance-matched with a

75

Ω load termination resistor to prevent unwanted signal distortion. The output waveforms should be monitored

using a low-capacitance probe on an oscilloscope with at least 500 MHz bandwidth. See PCB LAYOUT

CONSIDERATIONS for more information about signal and supply trace routing and component placement. Also,

refer to the “LMH1980 Evaluation Board Instruction Manual” Application Note (AN-1618 [SNLA096]).

SDTV Vertical Interval Timing Diagrams (NTSC, PAL, 480I, 576I)

Figure 3. NTSC Odd Field Vertical Interval

Copyright © 2007–2013, Texas Instruments Incorporated

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