Changhong Electric PF2939, Service Manual, Page: 21 / 47

SERVICE MANUAL
19
STR-G8656 (IC801)
The Series STR-G 86656/5653/F6654 is specifically designed to satisfy the requirements for increased
integration and reliability in off-line quasi-resonant flyback converters. The series incorporates a
high-precise error amplifying control and drive circuit with discrete avalanche-rated power MOSFET,
featuring fewer external components, small-size and standard power supply.
Covering the power range from below 25 watts up to 300 watts for 100/115/230 VAC inputs, and up to
150 watts for 85 to 265 VAC universal input, these devices can be used in a range of applications,
from battery chargers and set top boxes, to televisions, monitors, and industrial power supply units.
Cycle-by-cycle current limiting, under-voltage lockout with hysteresis, over-voltage protection, and
thermal shutdown protects the power supply during the normal overload and fault conditions.
Low-current startup and a low-power standby mode selected from the secondary circuit completes
a comprehensive suite of features. The series is provided in a five-pin overmolded SIP style package,
affording dielectric isolation without compromising thermal characteristics.
1. Features
·
Flyback Operation with Quasi-Resonant Soft Switching for Low Power Dissipation and EMI
·
Rugged Avalanche-Rated MOSFET
Soft drive circuit MOSFET
Adjustable MOSFET switching speed
·
Choice of MOSFET Voltage and Rds(on)
·
Full Over-Current Protection (no blanking)
·
Under-Voltage Lockout with Hysteresis
·
Over-Voltage Protection
·
Direct Voltage Feedback
·
Low Start-up Current (100
μ
Amax)
·
Low-Frequency, Low-Power Standby Operation
·
Overmolded 5-Pin Package
2
.
Circuit Block Diagram
Fig.13