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Datasheet

Datasheet

BM1P105FJ

TSZ02201-0F2F0A200170-1-2

2.Oct.2013.Rev.001

© 2013 ROHM Co., Ltd. All rights reserved.

www.rohm.com

TSZ22111・15・001

Figure 9. Waveform of No-load Startup

Figure 10. Waveform of High-load Startup

(3) VCC pin protection function

This IC includes a VCC pin under voltage protection function VCC UVLO (Under Voltage Protection) and overvoltage

protection function VCC OVP (Over Voltage Protection).

The VCC UVLO function and VCC OVP function prevent damage to the switching MOSFET that can occur when the VCC

voltage drops or becomes excessive.

(3-1) VCC UVLO and VCC OVP functions

VCC UVLO is an auto recovery type comparator with voltage hysteresis. For VCC OVP, the BM1P105FJ has an auto

recovery type comparator.

The operation is shown in Figure 11.

A mask time T

VCC pin (pin 6) voltage continues to exceed V

OVP

This function masks surges or the like that occur at the pin. (See section (7) below.)

VCCuvlo1=13.5Vtyp

OFF

ON

OFF

ON

Vovp1=27.5Vtyp

VCCuvlo2= 8.2Vtyp

ON

OFF

ON

OFF

ON

OFF

A

BC

D E

F

OFF

G HI

J

K

L

M

Vovp2= 23.5Vtyp

N

O

ON

ON

ON

P

Figure 11. VCC UVLO / OVP Time Chart

VCC voltage

VH voltage

Secondary

output

VCC voltage

VH voltage

Secondary

output

Within 64ms

Within 64ms