PWM-QR (quasi resonant) Flyback ICs
Infineon latest 5th generation quasi-resonant flyback PWM controller ICE5QSAG offers high performance and comprehensive suite of protection to increase system robustness. With a patent pending novel quasi-resonant implementation, an intelligent adaptive digital algorithm has enabled the PWM controller to minimize the spread of switching frequency under different AC line input conditions.
This innovative approach has enabled SMPS designers to design with higher switching frequency to take advantage of smaller magnetics and lowering of system BOM cost. To increase system robustness, both line input OVP and brown IN/OUT protection have been incorporated thereby reducing BOM count with high integration. To prevent controller damage due to abnormal start-up conditions, VCC and CS pin short to ground protection have been implemented to further enhanced system robustness.
To minimize interruption to system operation, all protection modes are implemented with auto-resume to enhance user experience. 5th generation quasi-resonant PWM controller ICE5QSAG is targeted for SMPS applications such as auxiliary power supply for home appliances (e.g. washing machines, refrigerators and air-condition), set-top-box, LCD/LED monitor and general purpose power supply up to a maximum output power of 60W.
Comparison between 5Q and 2Q quasi-resonant flyback controller
|Switching Scheme||Novel QR||QR||QR|
|Zero Crossing Counters||10||7||7|
|HV Start-up Cell||Cascode||Yes||No|
|Active Burst Mode||QR||FF-52Khz||N/A|
|Selectable Active Burst Mode||Yes||No||N/A|
|Line Input OVP||Auto-restart||N/A||N/A|
|VCC pin Short to Ground||Yes||N/A||N/A|
|CS pin Short to Ground||Yes||N/A||N/A|
|Adjustable OLP Blanking Time||No||No||Yes|