UC3845AD Microsemi Analog Mixed Signal Group, UC3845AD Datasheet - Page 8
UC3845AD
Manufacturer Part Number
UC3845AD
Description
IC CTRLR PWM CURRENT MODE 14SOIC
Manufacturer
Microsemi Analog Mixed Signal Group
Datasheet
1.UC3844AM.pdf
(8 pages)
Specifications of UC3845AD
Pwm Type
Current Mode
Number Of Outputs
1
Frequency - Max
500kHz
Duty Cycle
50%
Voltage - Supply
8.2 V ~ 25 V
Buck
Yes
Boost
Yes
Flyback
Yes
Inverting
No
Doubler
No
Divider
No
Cuk
No
Isolated
Yes
Operating Temperature
0°C ~ 70°C
Package / Case
14-SOIC (3.9mm Width), 14-SOL
Frequency-max
500kHz
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
UC3845AD1
Manufacturer:
TI
Quantity:
5 162
Part Number:
UC3845AD8TR
Manufacturer:
TI/UNITRODE
Quantity:
20 000
Company:
Part Number:
UC3845AD8TRG4
Manufacturer:
ST
Quantity:
16 109
Company:
Part Number:
UC3845ADM-TR
Manufacturer:
VIA
Quantity:
30
Company:
Part Number:
UC3845ADTR
Manufacturer:
TI
Quantity:
14 698
UC184xA/284xA/384xA
8
SPECIFICATIONS
Input line voltage:
Input frequency:
Switching frequency:
Output power:
Output voltage:
Output current:
Line regulation:
Load regulation:
Efficiency @ 25 Watts,
Output short-circuit current:
INPUT
AC
V
V
IN
IN
3.6k
= 90VAC:
= 130VAC:
1N4004
1N4004
0.01µF
20k
100pF
150k
1N4004
1N4004
10k
.0022µF
4.7k
T Y P I C A L A P P L I C A T I O N C I R C U I T S
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
1W
2
1
8
4
UC3844A
V
COMP
V
R
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
T
FB
REF
/C
C
220µF
250V
16V
T
U R R E N T
P
R O D U C T I O N
GND
V
7
5
CC
FIGURE 8. — OFF-LINE FLYBACK REGULATOR
OUT
CUR
SEN
140k
1/2W
6
3
M
0.01µF
O D E
4.7k
27k
2W
470pF
P W M C
1k
* This circuit uses a low-cost feedback scheme in which the DC
1N4935
D
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.
10µF
20V
A T A
O N T R O L L E R
0.85k
3600pF
400V
1N4935
S
H E E T
820pF
(continued)
2.5k
BOUNDARY
ISOLATION
TI
MBR735
4700µF
10V
2-5A
5V
Copyright © 1995
Rev. 1.2a 10/25