DD311 Datasheet, PDF (6/15 Pages) Silicon Touch Technology Inc. – HIGH CONSTANT CURRENT LED DRIVER

點晶科技股份有限公司
SILICON TOUCH TECHNOLOGY INC.
新竹市科學園區展業一路 9 號 7 樓之 1
9-7F-1, Prosperity RoadⅠ, Hsin-Chu, Taiwan, R.O.C.
Tel：886-3-5645656
Fax：886-3-5645626
Optional
R
C
IREF
REXT
EN
OUT
VSS
GND
DD311
VL
RL
CLED
Optional
CL
Switching Characteristics Test Circuit
Transient Characteristics
In order to reduce the overshoot or undershoot(Vout) during switching large current, it is
recommended adding a large enough capacitor between VLED and GND to keep LED supply
voltage(VLED) stable. The longer rise time and fall time of the EN dimming signal, adjustable by
RC filter, produce the smooth transient response of output current. The two output waveforms
illustrating the EN dimming signal with and without RC filter are given below:
without RC filter
HIGH CONSTANT CURRENT LED DRIVER
with RC filter
Version:PRE.001
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