This reference design report introduces the design method of using TOP258PN to make a 35W power supply, which supports 90VAC to 265VAC input, 5V 2.2A and 12V 2A output, and can be applied to LCD monitors.
This engineering report describes a 35 W dual‑output power supply built around the TOP258PN controller. It provides specifications, schematics, bill of materials, transformer details, PCB layout and performance data for an LCD monitor application.
The document includes safety and EMI compliance information, thermal performance, waveforms and control‑loop measurements, and a revision history. It is intended as an evaluation platform for designers working with Power Integrations' TOPSwitch‑HX family.
| Input Voltage | 90‑265 VAC |
|---|---|
| Output Voltage 1 | 4.75‑5.25 V ±5 % |
| Output Current 1 | 2.2 A |
| Output Voltage 2 | 9.6‑12 V ±20 % |
| Output Current 2 | 2 A |
| Continuous Output Power | 35 W |
| Full‑Load Efficiency | 82 % |
| No‑load Input Power (230 VAC) | 0.3 W |
| Standby Input Power | 1 W |
| EMI Compliance | Meets CISPR‑22B / EN55022B |
| Safety Class | II |
| Ambient Temperature Range | 0‑50 °C |
The design operates from 90 VAC to 265 VAC.
The power supply can deliver up to 35 W of continuous output.
Full‑load efficiency is measured at 82 %.
Yes, it meets CISPR‑22B and EN55022B conducted EMI requirements.