mb3881pff Fujitsu Microelectronics, Inc., mb3881pff Datasheet - Page 20

• Manufacturer Part Number: mb3881pff
• Description: 8-ch Dc/dc Converter Ic With Synchronous Rectifier For Voltage Step-up And Step-down
• Manufacturer: Fujitsu Microelectronics, Inc.

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MB3881
CH2 (CH7) output voltage
V
• When the CTL-2 (CTL-4) terminal is driven low (“L” level) after channels 1, 3, 4, and 8 have been soft-started
The capacitor (Cs) connected to the CS terminal (pin 32) starts being charged. The channel-2 (channel-7) output
voltage is soft-started by the error amplifier in proportion to the CS pin voltage.
(1) to (4)
(2) to (3)
(5) to (6)
(5)’ to (6)’
CH5, CH6 output voltage
V
O
CH8 output voltage
V
O
2 (V
CTL-3 ( pin 30)
Input
Output
5, V
O
8
CH1, CH3, CH4
output voltage
V
CTL-2 ( pin 29)
O
VREF ( pin 24)
O
(CTL-4 ( pin 31) )
7)
CTL-1 ( pin 28)
6
VB ( pin 36)
O
CS ( pin 32)
1, V
FB8 ( pin 4)
O
3, V
: Channel-2 (channel-7) soft start interval (waveform) as CTL-2 (CTL-4) goes
: Channel-2 (channel-7) soft start interval
: Channel-1, 3, 4 soft start interval
: Channel-8 soft start interval
“H” from “L” during channel-1, 3, 4 soft start interval
O
4
2.5 V
2 V
0.3 V
(1)
(2)
(5)
1.25 V
(3)
(6)
(4)
(5)
1.25 V
(6)
t