SG3842DM Microsemi Analog Mixed Signal Group, SG3842DM Datasheet - Page 14

• Manufacturer Part Number: SG3842DM
• Description: IC PWM CURRENT MODE 8SOIC
• Manufacturer: Microsemi Analog Mixed Signal Group

Specifications of SG3842DM

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 500kHz
• Duty Cycle: 100%
• Voltage - Supply: 8.2 V ~ 30 V
• Buck: No
• Boost: No
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: 0°C ~ 70°C
• Package / Case: 8-SOIC
• Frequency-max: 500kHz
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

SG1842/SG1843 Series
14
INPUT
AC
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:
3.6kW
V
V
0.01µF
IN
IN
= 90VAC:
= 130VAC:
20kW
673-3
150kW
100pF
10kW
.0047µF
4.7W 1W
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
SG1842
V
COMP
V
R
T
FB
REF
/C
220µF
250V
16V
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
C
T
U R R E N T
P
GND
V
R O D U C T I O N
CC
OUT
CUR
SEN
FIGURE 25. — OFF-LINE FLYBACK REGULATOR
56kW
1W
- M
0.01µF
27W
O D E
20kW
470pF
P W M C
1kW
* This circuit uses a low-cost feedback scheme in which the DC
1N3613
D
voltage developed from the primary-side control winding is
sensed by the SG1842 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
0.85W
0.01pF
400V
1N3613
S
H E E T
820pF
(continued)
2.5kW
BOUNDARY
ISOLATION
TI
T1: Coilcraft E - 4140 - b
Primary - 97 turns
Secondary - 4 turns
Control - 9 turns
single AWG 24
4 parallel AWG 22
3 parallel AWG 28
USD 735
4700µF
10V
Copyright © 2000
Rev. 1.6a 10/04
2-5A
5V