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Datasheet

Datasheet

BM2PXX4 Series

TSZ02201-0F2F0A200070-1-2

28.NOV.2012.Rev.003

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

www.rohm.com

TSZ22111・15・001

(5) Over Current limiter

BM2PXX4 is built in Over Current limiter per cycle. If the SOURCE pin over a certain voltage, switching is stopped. It is also

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

Shown in figure-12,13, 14.

Figure 12. No AC voltage compensation function

Figure13. buit-in AC compensation voltage

Primary peak current is decided as the formula below.

Primary peak current:

Figure 14. Over current limiter voltage

（

6）L.E.B blanking period

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

Therefore, when SOURCE pin voltage rises temporarily, the detection errors may occur in the over current limiter circuit.

To prevent detection errors, DRAIN is switched from high to low and the SOURCE signal is masked for 250 ns by the on-chip

LEB (Leading Edge Blanking) function.