Datasheet

Datasheet

29/34

TSZ02201-0F1F0C100240-1-2

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

15.Feb.2016 Rev.006

www.rohm.com

TSZ22111・15・001

BD9486F

3.5.7 LED OCP Detection

STB

3.0V

Abnormal

COUNTOR

ISENSE

SS

GATE

DIMOUT

Smaller than

4count

4count

4count

NORMAL

LEDOCP

(OFF)

NORMAL

abnormal

Reset

(*1)

(*2)

(*3)

(*4) (*5)

NORMAL

Latch off

STATE

(*6)

(*7)

(*8)

abnormal

abnormal

LEDOCP

LEDOCP

PWM

0.4V

3.0V

3.0V

3.0V

3.0V

3.0V

Latch off

RT

2.0V

REG50

Figure 38. LED OCP Detection

(*1)…If ISENSE>3.0V, LEDOCP is detected, and GATE becomes L. To detect LEDOCP continuously, The DIMOUT is

compulsorily high, regardless of the PWM dimming signal.

(*2)…When the LEDOCP releases within 4 counts of the GATE frequency, the boost operation restarts.

(*3) …As the LEDOCP is detected again, the boost operation is stopped.

(*4)…If the LEDOCP detection continues up to 4 counts of GATE frequency. IC will be latched off.

(*5)…Once IC is latched off, the boost operation doesn't restart even if the LEDOCP releases.

(*6)…The latch off state can be reset by the STB=L.

(*7)…It normally starts by STB=L to H.

(*8)…The operation of the LEDOCP detection is not related to the logic of the PWM.