Datasheet

Datasheet

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BD81A24MUV-M/EFV-M

TSZ02201-0T3T0C600070-1-2

© 2016 ROHM Co., Ltd. All rights reserved.

2016.10.19 Rev.003

www.rohm.com

TSZ22111・15・001

(9) Output Voltage Discharge Circuit (VDISC function)

When EN restart with Vout charge remaining, there is the possibility of LED flicker. Therefore restarting DC/DC must be

operated after discharging Vout. If using only pull-down resistance as setting OVP for discharge, it takes a lot time for

discharging Vout. Therefore this product has functionality of circuit for Vout discharge. Vout discharge function is

available for Buck Boost or Buck application. It is need to connect Vout and VDISC terminal and use VDISC function.

When VDISC terminal is connected to Vout, the output can be discharged when DCDC circuit becomes OFF (with EN

changing high to low or detection of protect).

The discharge time Tdisc is expressed in the following equations.

[ ] =

3×

[ ] ×

[ ]

4 ×

[ ]

Where:

Tdisc: DC/DC Output Discharge Time

COUT: DC/DC Output Capacity

Vout: DC/DC Output Voltage

IDISC: Discharge current

Please confirm IDISC value that 25% of Vout voltage from following graph and input above equation. For example,

when using Vout=20V, please use IDISC value of Vout=5V (approximately 76mA). It will take Tdisc time for Vout

discharge. Please set EN=Low time over than Tdisc for prevent LED flicker.

This Tdisc value is reference data. Please verifying by actual measurements.

Figure 10. Vout vs IDISC

0.00

0.02

0.04

0.06

0.08

0.10

0.12

0

5

10

15

20

25

30

35

40

Vout [V]

Vout vs IDISC