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Datasheet

Datasheet

BM1P061FJ / BM1P062FJ / BM1P101FJ / BM1P102FJ

TSZ02201-0F2F0A200090-1-2

22.NOV.2012.Rev.003

© 2012 ROHM Co., Ltd. All rights reserved.

www.rohm.com

TSZ22111・15・001

(5) Over Current limiter

BM1Pxxx is built in the Over Current limiter per cycle. If the CS pin is over a certain voltage, the switching is stopped. It is

also built in the AC voltage compensation function. The function is rise over the current limiter level by time to compensate

AC voltage.

Shown in figure-12,13,14

Figure 12. No AC voltage compensation function

Figure 13.buit-in AC compensation voltage

The primary peak current is decided as the formula below.

The primary peak current:

Ipeak = Vcs/Rs + Vdc/Lp*Tdelay

Figure 14. Over current limiter voltage

（

6）L.E.B blanking period

When the driver MOSFET is turned ON, a surge current occurs at capacitor components and the drive current.

Therefore, because of rising the CS pin voltage temporarily, the detection errors may occur in the over current limiter

circuit. To prevent detection errors, when the OUT pin is switched from high to low, the CS signal is masked for 250 ns by

the on-chip LEB (Leading Edge Blanking) function. This blanking function reduces CS pin noise filter for the noise that

occurs when the OUT pin is switched from high to low.