DM134

點晶科技股份有限公司

SILICON TOUCH TECHNOLOGY INC.

16-Bit Constant Current LED Drivers

-13-

Version

：A.013

System Configuration Example

Sink current is set by the external resistor as shown in the figure of Iout vs. Rext.

= V

To prevent too much power from dissipating by the higher V

additional R can be used to reduce the Vout when the outputs consume current is as follows:

R =

(max)

*

(max)

(min)

Bit

I

V

V

V

V

O

O

f

CE

LED

−

−

−

Note

This device has only one ground pin shared by signal, output sink current, and power ground. It is

advisable to pattern the ground layout with minimized inductance so that the switching noise induced

by the input signals and the output sink current would not cause chip malfunction. To prevent drivers’

outputs from damaging by overshoot stresses, it is also advisable not to turn off the drivers and scan

transistors simultaneously. For the QFN package, the IC’s thermal pad, which is internally connected to

the bottom side of chip, should be connected to GND. In addition, a good PCB layout pattern of the

thermal pad is required in order to have a better performance in thermal effect.

SERIAL-OUT

OUT15

OUT0

GND

R-EXT

LATCH

CPU

SERIAL-IN

SCAN

CLOCK

SERIAL-OUT

OUT15

OUT0

GND

R-EXT

LATCH

SERIAL-IN

CLOCK

R

＋

—

Vf

Vo

—

＋

ENABLE

ENABLE