DM133

點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

16-Bit Constant Current LED Drivers

-12-

Version

：A.024

There’s a simple procedure to implement the sequence of open detection for a specified

LED module.

Example:

Take the 4x32 LED module as an example. Once the controller received the alarm signal, then

1.

2.

Set DATASEL=H and Shift 32 clocks of ‘1’ into the ICs to turn on all 32 outputs, then set

LATCH=H ,ENABLE=L.

3.

Turn on the SW1 and watch the alarm line to see whether its voltage level is from ‘H’ to ‘L’ or not.

Scan all the lines to identify which row has problem.

4.

Once any row has problem.

5.

Shift 32 clocks of ‘0’ into the ICs to turn off all 32 outputs.

6.

Shift an ‘1’ and follow the other 31 ‘0’s to the LED module clock-by-clock, then the controller can

watch the alarm line to see whether its voltage level is from ‘H’ to ‘L’ or not. Then the opened LED

will be identified.

7.

Switch to the next problem row and repeat the step 6.

Follow the above steps, we recognize which LED fails as the controller receives an ‘0’

at 17

module.

The procedure described above is easy for implementation, the control system

doesn’t need an extra memory to handle the patterns comparison or to switch modes

back and forth.

Alarm

DM133

Alarm

DM133

R

SW1

SW2

SW3

SW4

open