MB3827 Datasheet, PDF (22/41 Pages) Fujitsu Component Limited. – 6-ch DC/DC Converter IC With Synchronous Rectification for voltage step-up and step-down

MB3827
4. Soft Start Operation
(1) Operating Description
• Simultaneous “H” level of CTL1-4, 7 terminal, and CTL5 terminal, CTL6 terminal
When CTL1-4, 7 terminal (pin 27) , and CTL5 terminal (pin 28) , CTL6 terminal (pin 29) are started at the same
time, the capacitor (CDTC) connected to DTC7 terminal (pin 9) starts charging. When the DTC7 terminal (pin 9)
voltage reaches 0.6V, the capacitors (CS) connected to the CS1-6 terminal (pin 30) start charging. The error
amplifier thus provides the output voltage from channels 1 to 6 with a soft start operation in proportion to the
voltage at pin CS1-6.
CTL1−4, 7 (pin 27)
CTL5 (pin 28)
CTL6 (pin 29)
DTC7 (pin 9)
Channel 7
output voltage
CS1−6 (pin 30)
0.77 V
0.6 V
0.3 V
1.26 V
Channel 1 to 6
output voltage
t
(1) (2) (3)
(4)
(1) to (2) : Channel 7 soft start interval
(3) to (4) : Channel 1 to 6 soft start interval
22