Datasheet > AN-19

AN-19

更新时间： 2022-01-18 22:18:00

品牌	Logo	应用领域
其他 - ETC		/
页数	文件大小	规格书
20页	180K
描述
TOPSwitch Flyback Power Supply Efficiency

阅读下载

获取价格

数据手册

如果您发现信息不准确，欢迎纠错

AN-19 数据手册

TOPSwitch Flyback Power

Supply Efficiency

Application Note AN-19

andconventionalpowersupplydesigns,efficiencymeasurement

techniques, and general design considerations for constructing

efficient flyback power supplies using TOPSwitch. For a more

detailed treatment of flyback power supply and transformer

design refer to application notes AN-16, AN-17 and AN-18.

Introduction

Efficiency should be a major consideration when designing a

flyback switching power supply. It can impact many aspects of

a product design, from enclosure size and ventilation to safety

qualification. Many design choices affect the efficiency of a

givenpowersupplydesign, includingsuchseeminglydisparate

factors as the value of the bulk storage capacitor, transformer

core geometry and construction, choice of output rectifier, and

snubber and clipper networks. This application note will

concentrate on efficiency comparisons between TOPSwitch

TOPSwitch vs. Discrete Design

For a given output power, the efficiency attainable with a

TOPSwitch flyback power supply is equal to or better than a

conventional power supply design using a PWM IC controller

Design Type:

(On Resistance/Voltage Rating)

3842 + MOSFET

(1.2 Ω/600V)

TOPSwitch

(3.6 Ω/700V)

DISCRETE vs. TOPSwitch PERFORMANCE (@ V_IN= 120 VAC)

Output Power

Input Power

34.27 W

39.38 W

87%

34.21 W

38.63 W

88.6%

Efficiency

Power Loss

5.11 W

76 KHz

4.42 W

100 KHz

Operating Frequency

POWER LOSS BUDGET

0.37 W

0.16 W

1.07 W

None

MOSFET R_DS(ON)

Conduction Loss

Switching Loss

Current Sense Resistor

MOSFET CV²f LOSS

MOSFET Crossover Loss

Start Up Circuit

0.43 W

0.32 W

Negligible

0.05 W

0.98 W

1.07 W

1.08 W

0.03 W(1-2 W*)

0.3 W

PWM Controller

Other Losses

1.00 W

Output Diode

1.20 W

Clamp Circuit

Miscellaneous Loss

(Input Filter, Bridge,

0.54 W

0.93 W

Transformer, Output Filter,

Secondary Feedback)

*A more conventional single resistor start-up circuit will dissipate 1-2 Watts.

Figure 1. Power Loss Comparison for Discrete and TOPSwitch Supplies.

June 1996

12 3 4 5 6 7...20

下载PDF

与AN-19相关器件

型号	品牌	描述	获取价格	数据表
AN1905	STMICROELECTRONICS	ST7MC THREE-PHASE BLDC MOTOR CONTROL SOFTWARE LIBRARY	获取价格
AN-1908	TI	The LM2842 is a PWM DC/DC buck (step-down) regulator.	获取价格
AN1943	MAXIM	Improving the Performance of the MAX4455 by Reducing On-Screen Display Artifacts	获取价格
AN1950	FREESCALE	Water Level Monitoring	获取价格
AN1955	FREESCALE	Thermal Measurement Methodology of RF Power Amplifiers	获取价格
AN197	SILICON	SERIAL COMMUNICATIONS GUIDE FOR THE CP210X	获取价格