SN28837

1/2-INCH PAL TIMER

SOCS031B – JULY 1991

14

POST OFFICE BOX 655303

VD (see Note A)

PS,T

PI

Power

SB (see Note A)

Powerup Operation

Normal Operation

SB

S1,S2,S3

ABIN

PD

GT

VD (see Note C)

PS,T

PI

S1,S2,S3

ABIN

GT

See Note D

1026 Pulses

Refresh Pulse

(see Note B)

290 Pulses

290 Pulses

290 Pulses

1026 Pulses

Refresh Pulses

(see Note B)

NOTES: A. A capacitor is connected to SB (between SB and GND).

B. Refresh pulses (1026 pulses) of PI, PS and T are generated even if VD is not fed back to GP.

C. VD is always fed back to GP and GPS is low.

D. PI, PS, S1, S2, S3, ABIN, and GT go low when SB is low.

Figure 10. Operation Chart of SB