FAN4800ASNY 데이터 시트보기 (PDF) - Fairchild Semiconductor

부품명

상세내역

제조사

FAN4800ASNY

PFC/PWM Controller Combination

Fairchild Semiconductor 

December 2010

FAN4800AS/CS/01S/2S

PFC/PWM Controller Combination

Features

ƒ Pin-to-Pin Compatible with ML4800 and FAN4800

and CM6800 and CM6800A

ƒ PWM Configurable for Current Mode or

Feedforward Voltage-Mode Operation

ƒ Internally Synchronized Leading-Edge PFC and

Trailing-Edge PWM in One IC

ƒ Low Operating Current

ƒ Innovative Switching-Charge Multiplier Divider

ƒ Average-Current Mode for Input-Current Shaping

ƒ PFC Over-Voltage and Under-Voltage Protections

ƒ PFC Feedback Open-Loop Protection

ƒ Cycle-by-Cycle Current Limiting for PFC/PWM

ƒ Power-on Sequence Control and Soft-Start

ƒ Brownout Protection

ƒ Interleaved PFC/PWM Switching

ƒ Improved Efficiency at Light Load

ƒ fRTCT=4•fPFC=4•fPWM for FAN4800AS/01S

ƒ fRTCT=4•fPFC=2•fPWM for FAN4800CS/02S

Applications

ƒ Desktop PC Power Supply

ƒ Internet Server Power Supply

ƒ LCD TV, Monitor Power Supply

ƒ UPS

ƒ Battery Charger

ƒ DC Motor Power Supply

ƒ Monitor Power Supply

ƒ Telecom System Power Supply

ƒ Distributed Power

Related Resources

ƒ AN-8027 - FAN480X PFC+PWM Combination

Controller Application

Description

The highly integrated FAN4800AS/CS/01S/02S parts

are specially designed for power supplies that consist of

boost PFC and PWM. They require very few external

components to achieve versatile protections /

compensation. They are available in 16-pin DIP and

SOP packages.

The PWM can be used in either current or voltage

mode. In voltage mode, feed-forward from the PFC

output bus can reduce the secondary output ripple.

Compared with older productions, ML4800 and

FAN4800, FAN4800AS/CS/01S/02S have lower

operation current that saves power consumption in

external devices. FAN4800AS/CS/01S/02S have

accurate 49.9% maximum duty of PWM that makes the

hold-up time longer. Brownout protection and PFC soft-

start functions available in this series are not available

in ML4800 and FAN4800.

To evaluate FAN4800AS/CS/01S/02S for replacing

existing FAN4800 and ML4800 boards, five things must

be completed before the fine-tuning procedure:

1. Change RAC resister from the old value to a higher

resister: between 6MΩ to 8MΩ.

2. Change RT/CT pin from the existing values to

RT=6.8kΩ and CT=1000pF to have fPFC=64kHz and

fPWM=64kHz.

3. The VRMS pin needs to be 1.224V at VIN=85 VAC

for universal input application from line input from

85VAC to 270VAC.

4. At full load, the average VVEA needs to be ~4.5V

and the ripple of VVEA needs to be less than

400mV.

5. For the Soft-Start pin, the soft-start current has

been reduced to half the FAN4800 capacitor.

There are two differences from FAN4800A/C/01/02 to

FAN4800AS/CS/01S/02S:

1. Under-voltage protection debounce time is

extended to one second.

2. PWM gate clamp voltage is raised to 19V.

© 2010 Fairchild Semiconductor Corporation

FAN4800AS/CS/01S/02S • Rev. 1.0.1

www.fairchildsemi.com

Share Link: