Example: Segment output pin S11 is controlled as follows:

BLK and the Display Control

Since the LSI internal data (SD1 to SD38 and the control data) is undefined when power is first applied, the display is

off (G1 and G2 = low) by setting the BLK pin low at the same time as power is applied. Then, meaningless display at

power on can be prevented by transferring all 56 bits of serial data from the controller while the display is off and setting

BLK pin high after the transfer completes. (See Figure 3.)

Power Supply Sequence

The following sequences must be observed when power is turned on and off. (See Figure 3.)

Figure 3

No. 3587-6/10

LC7573N, 7573NM

Display data

Segment output pin S11 state

SD11

SD30

0

0

The segments corresponding to both the G1 and G2 digit output pins are off.

0

1

The segment corresponding to the G2 digit output pin is on.

1

0

The segment corresponding to the G1 digit output pin is on.

1

1

The segments corresponding to both the G1 and G2 digit output pins are on.