SG1843 查看數據表（PDF） - Microsemi Corporation

零件编号

产品描述 (功能)

生产厂家

SG1843

Current Mode PWM Controller

Microsemi Corporation 

Typical Application Circuits

AC

INPUT

4.7Ω 1W

673-3

+ 220µF

250V

56kΩ

1W

0.01pF

400V

1N3613

1N3613

16V

20kΩ

SG1842

VCC

VFB

0.01 µF

+

10µF

20V

150kΩ

COMP

3.6kΩ

100 pF

VREF

0.01 µF

10kΩ

RT /CT

0.0047µF

OUT

CUR

SEN

GND

27Ω

20kΩ

1kΩ

470 pF

820pF

2.5kΩ

0.85Ω

T1

USD735

+

+

4700µF

10V

5V

2 – 5A

-

T1: Coilcraft E - 4140 – b

Primary - 97 turns

single AWG 24

Secondary - 4 turns

4 parallel AWG 22

Control - 9 turns

3 parallel AWG 28

ISOLATION

BOUNDARY

Figure 27 · Off-line Flyback Regulator

SPECIFICATIONS

Input line voltage:

90VAC to 130VAC

Input frequency:

50 or 60Hz

Switching frequency:

40kHz ±10%

Output power:

25W maximum

Output voltage:

5V +5%

Output current:

2 to 5A

Line regulation:

0.01%/V

Load regulation:

8%/A*

Efficiency @ 25 Watt:

VIN = 90VAC: 70%

VIN = 130VAC: 65%

Output short-circuit current: 2.5 A 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 SG1842 error amplifier. Load regulation is therefore dependent on the

coupling between secondary and control windings, and on transformer leakage inductance.

19

Share Link: