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BD906xx-C series

TSZ02201-0T1T0AL00130-1-2

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TSZ22111・15・001

15.Sep.2015 Rev.005

External Synchronization Function

In order to activate the external synchronization function, connect the frequency-setting resistor to the RT pin and then input

a synchronizing signal to the EN / SYNC pin.

is within ±20 % of the switching frequency.

Furthermore, the pulse wave

’s LOW voltage should be under 0.8 V and the HIGH voltage over 2.6 V (when the HIGH voltage

is over 11 V the EN / SYNC input current increases), and the slew rate (rise and fall) under 20 V / µS. The ON Duty of

External clock should be configured between 10 % and 90 %.

The frequency will synchronize with the external clock operation frequency after three external sync pulses is sensed.

Eternal SYNC Sample Circuit

PVIN

VIN

RT

EN / SYNC

GND

SW

FB

VC

Cbulk

D1

R3

C1

L1

R2

C2