基于TOP265EG设计的30W待机电源方案

TOPSwitch-JX系列(TOP264-271)集成了725V功率MOSFET,高压开关电流源,多模式PWM控制,热关断电路,故障保护和其它控制电路, 265 VAC电压下无负载的功耗低于100mW.本文介绍了TOPSwitch-JX系列(TOP264-271)主要特性, 方框图, 通用输入高效19V 65W反激电源电路图和采用TOP265EG的12V 30W高效待机电源设计案例的电路图和所用材料清单.

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.

TOPSwitch-JX 系列主要特性:

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 highest efficiency requirements

• Accurate programmable current limit

• Optimized line feed-forward for line ripple rejection

• 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


图1.TOPSwitch-JX系列功能方框图(E 和V 封装).
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图2.TOPSwitch-JX系列通用输入高效19V 65W反激电源电路图

采用TOPSwitch-JX系列TOP265EG的12V 30W高效待机电源设计案例

12V 30W设计案例主要特性:

Highly energy efficient

Full load efficiency >90%

Efficiency >87% above 10% load

Average efficiency >90% (25%, 50%, 75%, 100% load points)

No-load input power <100 mW

Simplifies meeting ENERGY STAR 2.0, 80 Plus and EuP requirements

725 V MOSFET rating allowed high turns ratio (VOR) and use of 60 V Schottky output diode

Low cost, low component count and small PCB footprint solution

Performance met without synchronous output rectification

132 kHz operation optimized core size and efficiency performance

Low-profile eSIP package

Integrated Protection and Reliability Features

Line under-voltage lock out (UVLO)

Primary sensed latching output overvoltage shutdown (OVP) with fast AC reset

Auto recovery output over current (OCP)

Meets limited power source (LPS) <100 VA requirement with a single point of failure

Accurate thermal shutdown with large hysteresis


图3.设计案例PCB外形图(2.97 x 2.14 吋).

设计电源指标:


图4. 12V 30W设计案例电路图

设计案例材料清单:


图5. 12V 30W设计案例变压器电框图