BD8381EFV-M
Technical Note
8. Setting of the soft-start
The soft-start allows minimization of the coil current as well as the overshoot of the output voltage at the start-up.
For the capacitance we recommend in the range of 0.001 0.1µF. For the capacitance less than 0.001µF may cause
overshoot of the output voltage. For the capacitance greater than 0.1µF may cause massive reverse current through the
parasitic elements of the IC and damage the whole device. In case it is necessary to use the capacitance greater than
0.1µF, ensure to have a reverse current protection diode at the Vcc or a bypass diode placed between the SS-pin and the
Vcc.
Soft-start time TSS
TSS = CSSX0.7V / 5uA [s]
CSS: The capacitance at the SS-pin
9. Verification of the operation by taking measurements
The overall characteristic may change by load current, input voltage, output voltage, inductance, load capacitance,
switching frequency, and the PCB layout. We strongly recommend verifying your design by taking the actual
measurements.
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2011.04 - Rev.A