This document describes a SMPS circuit design for LCD monitors or LCD-TVs. The circuit meets global power saving requirements and uses standard thru-hole technology, which can be easily converted to SMT technology.
The document details a reference design for a 60W wide-range power supply (90-265Vrms input) delivering 5V and 12V outputs for LCD TV sets or monitors. The design utilizes the L5991 current mode primary controller and meets stringent standby power requirements of less than 0.8W at 230Vac. It features fault protections such as output short circuit and over voltage, along with safety compliance to EN60950 and EMC Class-B standards.
| Input Voltage | 90 + 265 Vrms - 45-66 Hz |
|---|---|
| Output Voltages | 5.1V+2% @2A and 12V+10% @4A |
| Standby Input Power | Less than 0.8W @230Vac |
| Safety Standard | Acc. to EN60950 |
| EMC Standard | EN50022 Class-B |
| PCB Size | 180 x 89 mm |
The power supply accepts a full range input voltage from 90 to 265Vrms at 45-66 Hz.
The design delivers 5.1V+2% at 2A for the panel and digital circuitry, and 12V+10% at 4A for the backlight and audio.
The circuit is designed to meet standby rules with an input power consumption of less than 0.8W at 230Vac.
The core of the design is the current mode primary controller, the L5991.