This reference design provides isolated +24V (45W), ±16 V (4.5W), and +6V (0.5W) outputs to power the control electronics in variable speed drives. The power supply can be either powered directly from 3-phase AC mains (380Vac to 690Vac) or can be powered from the DC-link voltage (400Vdc to 1200Vdc). This design uses a quasi-resonant flyback topology and is rated for 50-Watt total output power. The line and load regulation of the power supply is designed to be within 5% using primary-side regulation (eliminating costly feedback components). The power supply is designed to meet the clearance, creepage, and isolation test voltages as per IEC61800-5 requirements.
- Versatile input: can be either 400V-1200V DC or 380V-690V AC
- <5% line and load regulation
- Protection against input UV/OV, output overload, short-circuit and loss of feedback
- Low-cost solution by implementing primary-side regulation (eliminates feedback loop) and use of 1000V rated MOSFETSs
- Quasi-resonant mode controller improves EMI performance
- Designed to comply to IEC 61800-5