mb3881pff Fujitsu Microelectronics, Inc., mb3881pff Datasheet - Page 24

• 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
SAMPLE POWER SUPPLY USING CHANNEL 8 AS SELF-POWER SUPPLY
Using channel 8 as the self-power supply, the MB3881 can support a wide range of supply voltages and operate
at low input voltage (Vin
The following example shows sample power supply using a transformer.
The following settings are used in “APPLICATION EXAMPLE”.
• VSS(O) is set to the number of turnings that produces Vin - 1.8 V.
• VCC and VCC(O) are set to the number of turnings that produces Vin + 2.2 V.
Note that, because channels 1 to 4 operate at VCC
produces Vin + 2.2 V or more so that they operate at Vin
H
FB8
IN8
IN8
4
5
6
1.8 V).
Error
Amp.8
64
2
OUT8
RB8
VSS (O)
4 V, they must be set to the number of turnings that
VCC
VCC (O)
1.8 V.
Vin
H
V
(15 V)
<CCD>
V
(7 V)
<LCD>
V
( 15 V)
<LCD>
V
( 7 V)
<CCD>
O
O
O
O
8-1
8-2
8-3
8-4