MB3821 Datasheet, PDF (3/24 Pages) Fujitsu Component Limited. – 2-ch DC/DC Converter IC With Synchronous Rectifier

MB3821
s PIN DESCRIPTION
Pin No.
1
2
3
4
5
6
7
8
9
10
11
12
13
14
Symbol
CT
RT
GND
CS1
–IN1
FB1
SEL
OUT1-1
VS1
CB1
OUT2-1
GND(0)
VB
OUT2-2
15
CB2
16
VS2
17
OUT1-2
18
CTL
19
FB2
20
–IN2
21
CS2
22
CSCP
23
VCC
24
VREF
I/O
Descriptions
— Triangular wave oscillator frequency setting capacitance connection pin.
— Triangular wave oscillator frequency setting resistance connection pin.
— Ground pin.
— Capacitor connection pin for Channel 1 soft start (also channel control).
I Channel 1 error amplifier inverted input pin.
O Channel 1 error amplifier output pin
I Mode select pin. Set the SEL pin to “H” level to switch the IC to low power mode.
I Totem pole type output pin (external main side FET gate drive).
— Channel 1 external main side FET source connection pin.
— Channel 1 boot capacitance connection pin.
O Channel 1 totem pole output pin (external main side FET gate drive).
— Ground pin for output circuit.
— Power supply pin for output circuit.
O Channel 2 totem pole output pin (external synchronous rectifier side FET gate
drive).
— Channel 2 boot capacitance connection pin.
— Channel 2 external main side FET source connection pin.
O Channel 2 totem pole output pin (external main side FET gate drive).
I Power supply control pin. Set CTL pin to “L” to switch the IC to standby mode.
O Channel 2 error amplifier output pin.
I Channel 2 error amplifier inverted input pin.
— Channel 2 soft start capacitance connection pin(also channel control).
— Timer-latch short circuit protection capacitance connection pin.
— Reference power supply, control circuit power supply pin.
O Reference voltage output pin.
3