mb3881pff Fujitsu Microelectronics, Inc., mb3881pff Datasheet - Page 21

• 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.

MB3881
(2) Setting Soft Start
• Channel-8 soft start
Channel 8 can be soft-started by connecting a capacitor between the DTC8 terminal (pin 3) and GND. The soft
start time depends on the input voltage and load current.
• Channel 1 to 4 and channel 7 soft start
Soft start time
ts[s] : = 1.25
Cs[ F]
Note : The short-circuit detection function remains working even during soft start operation of channels 1 to 4 and 7.
• Channel-5, 6 soft start
Channel 5 can be soft-started by connecting a capacitor between the +IN5 terminal (pin 22) and GND.
Channel 6, like channel 5, can be soft-started by connecting a capacitor between the +IN6 terminal (pin 16) and
GND.
SETTING THE OSCILLATION FREQUENCY
The oscillation frequency can be set by connecting the timing capacitor (C
) to the CT terminal (pin 34) and the
T
timing resistor (R
) to the RT terminal (pin 33).
T
Oscillation frequency
550000
f
(kHz) : =
OSC
C
(pF)
R
(k )
T
T
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