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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

(3) VCC pin protection function

BM1Pxxx built in VCCUVLO (Under Voltage Lock Out), VCC OVP (Over Voltage Protection) and VCC charge function that

operates in case of dropping the VCC voltage.

This function monitors VCC pin and prevent VCC pin from destroying switching MOSFET at abnormal voltage.

VCC charge function stabilizes the secondary output voltage to be charged from the high voltage line by start circuit when

dropping the VCC voltage.

(3-1) VCC UVLO ／ VCC OVP function

VCCUVLO is auto recovery comparator. BM1Pxx1 series have auto recovery type VCCOVP that has voltage hysteresis.

BM1Pxx2 series has latch type VCCOVP.

Refer to the operation figure-8.

This function built in mask time T

section (7))

VCCuvlo1

ON

OFF

Vovp

VCCuvlo2

ON

OFF

OFF

OFF

ON

OFF

A

B

CD

EF

OFF

L : Normal

H : Latch

G H

I

Vlatch

A

J

ON

ON

OFF

OFF

ON

ON

ON

ON

OFF

OFF

OFF

ON

OFF

K

Figure 8. VCC UVLO / OVP Timing Chart

A:The VH pin voltage input, the VCC pin voltage starts rising.

B:VCC>Vuvlo1, the DC/DC operation starts

C:VCC > V

D:VCC > V

OVP1

continues T

E:VCC< V

F:VCC > V

CHG2

G:Same as E.

H:Same as F.

I: The VH pin is OPEN. The VCC Voltage is fall.

J: VCC<Vuvlo2, the DC/DC operation stops

K: VCC<V

LATCH