FA7703 Datasheet, PDF (5/21 Pages) Fuji Electric – FUJI Power Supply Control IC

FA7703/04
4. Block diagram
REG
16
DT1
15
REF
14
FA7703/7704
IN1-
13
FB1
12
SEL1
11
OUT1
10
VCC
9
Reference
voltage
2.2V
1V
E r.A m p1
+
-
+
O N /O F F
ICS
+ PW M.Comp1
UVLO
BIAS
Power Good Signal ^BIAS
OSC
Er.Am p2
1.5V
1.3V
+
-
-
S.C.DET
+
-
+
+ _{PW M.Comp2}
S.C.P
2.0V
ON/OFF
FA7704
1
2
3
4
5
6
7
8
RT
CS
DT2
IN2+
IN2-
FB2
GND
OUT2
5. Selection Gide
FA7703 ^Ch.1(OUT1)
Ch.2(OUT2)
Buck, Boost, Fly-back
Buck, Inverting (Pch driven)
FA7704
Ch.1(OUT1)
Ch.2(OUT2)
Buck, Boost, Fly-back
Boost, Fly-back (Nch driven)
6. Pin assignment
Pin No
Pin
symbol
Description
1
RT
Oscillator timing resistor
2
CS
Soft start, Timer latched short circuit protection, ON/OFF control
3
DT2 Ch.2 Dead Time Adjustment
4
IN2+ Ch.2 non-inverting input to error amplifier
5
IN2- Ch.2 inverting input to error amplifier
6
FB2 Ch.2 output o error amplifier
7
GND Ground
8
OUT2 Ch.2 output
9
VCC Power supply
10
OUT1 Ch.1 output
11
SEL Selection of type of driven MOSFET (OUT1)
12
FB1 Ch.1 output o error amplifier
13
IN1- Ch.1 inverting input to error amplifier
14
REF Reference voltage
15
DT1 Ch.1 Dead Time Adjustment
16
REG Regulated voltage output
Fuji Electric Systems Co., Ltd.
AN-057E Rev.1.0
Jun-2010
5
http://www.fujielectric.co.jp/fdt/scd/