BD9011EKN_08 Datasheet, PDF (23/30 Pages) Rohm – Step-down, High-efficiency Switching Regulators (Controller type)

2) Oscillator Synchronization by External Pulse Signal
At the operation the oscillator is externally synchronized, input the synchronization signal into Fin in addition to connect a
resistor and a capacitor at RT and CT, respectively.
Input the external clock pulse on Fin, which is higher frequency than the fixed one. However, the frequency variation
should be less than 20%.
Also, the duty cycle of the pulse should be set from 10% to 90%.
Fin
： Fixed with RT and CT
CT
： Synchronized
CT Waveform during Synchronized with External Pulse
Short Fin to GND if the function of external synchronization is not needed.
Fin
Without Synchronization Signal
3)Setting the Over Current Threshold Level
The OCP detection level（Iocp）is determined by the ON resistance (R_ON) of the main MOSFET switch and the resistance
(Rcl) which is placed between CL and VCC.
Iocp ＝
Rcl
×10^-5 [A] （typ.）
R_ON
To prevent a malfunction caused by noise, place a capacitor（Ccl） parallel to Rcl.
If OCP function is not needed, short VS to VCC, and short CL to GND.
CL
VS
With OCP
VCC
Rcl
CL
Ccl
VS
To Main MOSFET Drain
Without OCP
VCC
CL, VS Pin Connection
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