PRODUCT DATABOOK 1996/1997
UC184xA/284xA/384xA
C
URRENT
M
ODE
PWM C
ONTROLLER
P
R O D U C T I O N
D
A T A
S
H E E T
T Y P I C A L A P P L I C AT I O N C I R C U I T S
FIGURE 8.
—
OFF-LINE FLYBACK REGULATOR
4.7kW
1W
220µF
250V
140kW
1/2W
AC
INPUT
1N4004
1N4004
1N4935
16V
20kW
4.7kW
2W
3600pF
400V
(continued)
TI
MBR735
1N4004
1N4004
4700µF
10V
5V
2-5A
1N4935
UC3844A
2
150kW
1
V
FB
COMP
7
V
CC
1N4935
0.01µF
10µF
20V
820pF
2.5kW
27kW
IRF830
OUT 6
3.6kW
100pF
8
10kW
4
R
T
/C
T
V
REF
CUR
3
SEN
GND
5
1kW
470pF
0.85kW
ISOLATION
BOUNDARY
0.01µF
.0022µF
SPECIFICATIONS
Input line voltage:
Input frequency:
Switching frequency:
Output power:
Output voltage:
Output current:
Line regulation:
Load regulation:
Efficiency @ 25 Watts,
V
IN
= 90VAC:
V
IN
= 130VAC:
Output short-circuit current:
90VAC to 130VAC
50 or 60Hz
40KHz ±10%
25W maximum
5V +5%
2 to 5A
0.01%/V
8%/A*
70%
65%
2.5Amp average
* This circuit uses a low-cost feedback scheme in which the DC
voltage developed from the primary-side control winding is
sensed by the UC3844A error amplifier. Load regulation is
therefore dependent on the coupling between secondary and
control windings, and on transformer leakage inductance.
8
Copyright © 1995
Rev. 1.2 12/95
MICROSEMI [ MICROSEMI CORPORATION ]
