BD9152MUV Datasheet, PDF (8/18 Pages) Rohm – Output 1.5A or Less High Efficiency Step-down Switching Regulator with Built-in Power MOSFET

BD9152MUV
Technical Note
●Description of operations
・Soft-start function
EN terminal shifted to “High” activates a soft-starter to gradually establish the output voltage with the current limited during
startup, by which it is possible to prevent an overshoot of output voltage and an inrush current.
・Shutdown function
With EN terminal shifted to “Low”, the device turns to Standby Mode, and all the function blocks including reference voltage
circuit, internal oscillator and drivers are turned to OFF. Circuit current during standby is 0μF (Typ.).
・UVLO function
Detects whether the input voltage sufficient to secure the output voltage of this IC is supplied. And the hysteresis width of
50mV (Typ.) is provided to prevent output chattering. Each the outputs have UVLO. It is possible to set output sequence
easy.
VCC
EN1,2
Hysteresis
100mV
Hysteresis
50mV
VOUT1
VOUT2
Ch1, Ch2
Standby mode
TSS
discharge ON
discharge ON
TSS
TSS
discharge ON
discharge ON
TSS
Ch1, Ch2
Operating mode
Natural discharge
Natural discharge
Natural discharge
TSS
TSS
Ch1
Standby mode
Ch2
Standby mode
Standby mode
Ch1 : standby mode
Ch2 : Operating mode
Ch1, Ch2
Operating mode
Ch1, Ch2
Operating mode
Ch1
Standby mode
Ch2
Standby mode
UVLO2 UVLO1
UVLO1
UVLO1 UVLO2
EN EN
UVLO1 UVLO2
Fig.30 Soft start, Shutdown, UVLO timing chart
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2009.05 - Rev.A