MB3881 Datasheet, PDF (19/40 Pages) Fujitsu Component Limited. – 8-ch DC/DC Converter IC with Synchronous Rectifier for Voltage Step-up and Step-down

MB3881
4. Soft Start Operation
(1) Description
• When the CTL-1 to CTL-4 pins are driven high (“H” level)
The channel-8 output voltage is soft-started by the capacitor (C+IN8) connected to the +IN8 terminal (pin 6).
The capacitor (Cs) connected to the CS terminal (pin 32) starts being charged and the output voltages of channels
1 to 4 and channel 8 are soft-started by the error amplifier in proportion to the CS pin voltage.
Input
CTL-1 ( pin 28 )
CTL-2 ( pin 29 )
CTL-3 ( pin 30 )
CTL-4 ( pin 31 )
Output
2V
VB ( pin 36)
FB8 ( pin 4)
0.3 V
CH8 output voltage
VO8
VREF ( pin 24)
2.5 V
CS ( pin 32)
1.25 V
CH1 to CH4, CH7
output voltage
VO1 to VO4, VO7
CH5, CH6 output
voltage VO5, VO6
t
(1) (2)
(3) (4)
(1) to (4) : CH1 to CH4, CH7 soft start interval
(2) to (3) : CH8 soft start interval
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