MB3883 Datasheet, PDF (20/39 Pages) Fujitsu Component Limited. – 6-ch DC/DC Converter IC With Synchronous Rectification for voltage step-up and step-down

MB3883
4. Soft Start Operation
1. Description
• When the CTL, CTL1,2, CTL3, CTL4, and CTL5 terminals are driven high (“H” level) at the same time
The capacitor (C+IN6) connected to the C+IN6 terminal (pin 5) starts charging. When the C+IN6 terminal voltage
falls below 0.9 V (Typ.), the capacitor (Cs) connected to the CS terminal (pin 15) starts charging and the error
amp. provides a soft start by comparing the CH1 to CH5 output voltage to the voltage at the CS terminal.
Input
CTL (pin 20)
CTL1, 2 (pin 21)
CTL3 (pin 22)
CTL4 (pin 23)
CTL5 (pin 24)
Output
2V
VB (pin 27)
C+IN6 (pin 5)
CH6 output voltage
Vo6
VREF (pin 16)
0.9 V
2.49 V
CS (pin15)
1.25 V
CH1 to CH5 output
voltage Vo1 to Vo5
t
(1)
(3) (2)
(4)
(1) to (2) : CH6 soft start interval
(3) to (4) : CH1 to CH5 soft start interval
20