BD9285F ROHM [Rohm], BD9285F Datasheet - Page 18

• Manufacturer Part Number: BD9285F
• Description: Boost 1channel white LED driver For large LCDs
• Manufacturer: ROHM [Rohm]

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© 2012 ROHM Co., Ltd. All rights reserved.
TSZ22111・15・001
BD9285F
●3.4.4 . how to set DCDC oscillation frequency
This equation is an ideal equation in which correction factors are not applied.
R
○ the relationship between OSC and R
The adequate verification with an actual set needs to be performed to set frequency precisely.
[setting example]
If DCDC oscillation frequency is 200kHz, we can calculate the R
RT
which connects to RT pin set the oscillation frequency of DCDC.
R
RT
f
15000
sw
where fsw is the oscillation frequency of DCDC [kHz]
[
kHz
]
R
RT
200
15000
[
kHz
f
SW
15000
RT
]
[
kHz
(ideal)
Ideal
75
]
18/36
[
[
k
k
]
]
RT
as below.
R
RT
TSZ02201-0F1F0C100030-1-2
Figure 25. RT pin setting example
RT
11.Jul.2012 Rev.001
Frequency (fsw)
GATE
GND
Datasheet
CS
Rcs