BD9285F Datasheet, PDF (12/39 Pages) Rohm – Boost 1channel white LED driver For large LCDs

BD9285F
Datasheet
is hold to the external capacitance.
(For more detail on the compensation setting is described in the section " 3.6 loop compensation".)
○Pin17: CS
The CS pin has two functions.
1. DC / DC current mode Feedback terminal
The inductor current is converted to the CS pin voltage by the sense resistor RCS
and this CS pin voltage controls the output voltage by compared with the error
amp output.
VIN
9285
2. Inductor current limit (OCP) terminal
The CS terminal also has a over current protection (OCP), if it voltage is more
than 0.5V, the switching operation will be stopped compulsorily.
GATE
Both of above functions are enable after 300ns (typ.) when GATE pin asserts
high, because the leading Edge Blanking function is included into this IC to
CS
prevent the affect noise. Please refer to the section 3.5.1 “DCDC parts selection /
how to set OCP”, for detail explanation.
Rcs
GND
○Pin18: TC54
This is the 5.4V (TYP.) output pin that is used for internal power supply.
Figure 15. CS pin circuit
Available current is 100uA
TC54 can be used as a timer for the discharge of output capacitance DCDC. For detailed instructions, please refer the
section 3.4.2 “how to shutdown and set TC54 capacitance”
www.rohm.com
© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
12/36
TSZ02201-0F1F0C100030-1-2
11.Jul.2012 Rev.001