LTC3783 Datasheet, PDF (21/24 Pages) Linear Technology – PWM LED Driver and Boost, Flyback and SEPIC Controller

U
OPERATIO
Using the LTC3783 for Buck Applications
As shown in Figure 12, high side current sensing also
allows the LTC3783 to control a functional buck con-
verter when load voltage is always sufficiently less than
LTC3783
V_IN. In this scheme the input voltage to the inductor is
lowered by the load voltage. The boost converter now
sees a V_IN’ = V_IN – V_LOAD, meaning the controller is now
boosting from (V_IN – V_LOAD) to V_IN.
V_IN
6V TO 36V
LED STRING
LTC3783
RUN
V_IN
PWMIN OV/FB
I_TH PWMOUT
SS
I_LIM
V_REF GATE
FBP SENSE
FBN INTV_CC
FREQ GND
SYNC
Figure 12. LED Buck Application
GND
3783 F12
3783f
21