30W standby power supply scheme based on TOP265EG design - Power Circuit - Circuit Diagram

The TOPSwitch-JX series (TOP264-271) integrates a 725V power MOSFET, high voltage switch current source, multimode PWM control, thermal shutdown circuitry, fault protection and other control circuitry. The no-load power consumption is less than 100mW at 265 VAC. This article introduces the main features of the TOPSwitch-JX series (TOP264-271), block diagram, general-purpose input high-efficiency 19V 65W flyback power supply circuit diagram and the circuit diagram and material list of the 12V 30W high-efficiency standby power supply design case using TOP265EG.

TOPSwitch-JX TOP264-271 cost effectively incorporates a 725 V power MOSFET, high voltage switched current source, multi-mode PWM control, oscillator, thermal shutdown circuit, fault protection and other control circuitry onto a monolithic device.

Main features of the TOPSwitch-JX series:

EcoSmart® - Energy Efficient

• Energy efficient over entire load range

• No-load consumption below 100 mW at 265 VAC

• Up to 750 mW standby output power for 1 W input at 230 VAC

High Design Flexibility for Low System Cost

• Multi-mode PWM control maximizes efficiency at all loads

• 132 kHz operation reduces transformer and power supply size

• 66 kHz option for the highest efficiency requirements

• Accurate programmable current limit

• Optimized line feed-forward for line

• Frequency jittering reduces EMI filter cost

Fully integrated soft-start for minimum startup stress

• 725 V rated MOSFET

• Simplifies meeting design derating requirements

Extensive Protection Features

• Auto-restart limits power delivery to <3% during overload faults

• Output short-circuit protection (SCP)

• Output over-current protection (OCP)

• Output overload protection (OPP)

• Output overvoltage protection (OVP)

• User programmable for hysteretic/latching shutdown

• Simple fast AC reset

• Primary or secondary sensed

• Line undervoltage (UV) detection prevents turn-off glitches

• Line overvoltage (OV) shutdown extends line surge withstand

• Accurate thermal shutdown with large hysteresis (OTP)

• Heat transfer to both PCB and heat sink

• Optional external heat sink provides thermal impedance equivalent to a TO-220

• eSIP®-7C package:

• Vertical orientation for minimum PCB footprint

• Simple heat sink mounting using clip provides thermal impedance equivalent to a TO-220

• Extended creepage to DRAIN pin

• Heat sink is connected to SOURCE for low EMI


Figure 1. Functional block diagram of the TOPSwitch-JX family (E and V packages).