FEDL9261A-01

OKI Semiconductor

ML9261A

11/16

FUNCTIONAL DESCRIPTION

Display Data Reset

When the power is turned on, the shift register outputs (PO1 to PO60) and register outputs (O1 to O60) are

indeterminate. Consequently the display of a VFD tube may flicker because unnecessary driver outputs go high.

To prevent such flicker, it is required to perform the following operations.

1. Turn on the logic power supply while the

CL input is kept low.

2. Set the LS input high.

3. Switch the CLK input from a low level to a high level at least once.

By performing the above operations, all of the shift register outputs (PO1 to PO60) and register outputs (O1 to

O60) are set low.

4. Enter display data.

5. Set the

CL input high.

Data Transfer

Write display data by using a serial transfer.

Serial data is input in the shift register at the rising edge of a CLK input pulse.

When the LS input rises, display data is written in the latch.

Driver Output Control

1. To turn on or off driver outputs by using display data transferred into the shift register, set the

CL input high

and set the CHG input low.

2. To set all the driver outputs low, set the

CL input low.

3. To set all the driver outputs high, set the

CL input and CHG input high at a time.