Fairchild 公司的FAN6756是采用創(chuàng )新mWSaver™技術(shù)的綠色模式PWM控制器,能大大地降低待機和無(wú)負載功耗,滿(mǎn)足世界范圍的待機模式效率指引.在230VAC時(shí)待機和無(wú)負載功耗為30mW(包括EMI濾波器功耗),具有多種保護如過(guò)載/開(kāi)路保護(OLP),UVLO,VDD OVP,超溫保護(OTP)和電流檢測短路保護(SSCP),主要用于筆記本電腦,打引機,LCD監視器,游戲機控制臺.本文介紹了FAN6756主要特性,方框圖,典型應用電路以及FAN6765MR評估板指標,電路圖,材料清單和PCB元件布局圖.
The FAN6756 is a next-generation Green Mode PWM controller with innovative mWSaver™ technology, which dramatically reduces standby and no-load power consumption, enabling conformance to worldwide Standby Mode efficiency guidelines.
An innovative AX-CAP™ method minimizes losses in the EMI filter stage by eliminating the X-cap discharge resistors while meeting IEC61010-1 safety requirements. Standby Mode clamps feedback voltage and modulates feedback impedance with an impedance
modulator during Burst Mode operation, which forces the system to operate in a “deep” Burst Mode with minimum switching losses.
Protections ensure safe operation of power system in various abnormal conditions. Proprietary frequencyhopping function decreases EMI emission and built-in synchronized slope compensation allows more stable Peak-Current-Mode control over wide range of input voltage and load conditions. The proprietary internal line compensation ensures constant output power limit over entire universal line voltage range.
Requiring a minimum number of external components, FAN6756 provides a basic platform that is well suited for cost-effective flyback converter designs that require extremely low standby power consumption.

FAN6756主要特性:
 Single-Ended Topologies, such as Flyback and Forward Converters
 mWSaver™ Technology
- Achieves Low No-Load Power Consumption:
Less than 30mW at 230VAC (EMI Filter Loss Included)
- Eliminates X Capacitor Discharge Resistor Loss with AX-CAP™ Technology
- Linearly Decreases Switching Frequency to 23KHz
- Burst Mode Operation at Light-Load Condition
- Impedance Modulation in Standby Mode for “Deep” Burst Mode Operation
- Low Operating Current (450μA) in Standby Mode
- 500V High-Voltage JFET Startup Circuit to Eliminate Startup Resistor Loss
 Highly Integrated with Rich Features
- Proprietary Frequency Hopping to Reduce EMI
- High-Voltage Sampling to Detect Input Voltage
- Peak-Current-Mode Control with Slope Compensation
- Cycle-by-Cycle Current Limiting with Line Compensation
- Leading Edge Blanking (LEB)
- Built-In 8ms Soft-Start
 Advanced Protections
- Brown-In/Brownout Recovery
- Internal Overload/Open-Loop Protection (OLP)
- VDD Under-Voltage Lockout (UVLO)
- VDD Over-Voltage Protection (VDD OVP)
- Over-Temperature Protection (OTP)
- Current-Sense Short-Circuit Protection (SSCP)

FAN6756應用:
Flyback power supplies that demand extremely low standby power consumption, such as:
 Adapters for Notebooks, Printers, Game Consoles, etc.
 Open-Frame SMPS for LCD TV, LCD Monitors, Printer Power, etc.

圖1.FAN6756方框圖

圖2.FAN6756典型應用電路圖


圖3.FAN6756 65W筆記本電腦電源電路圖

FAN6765MR評估板
This user guide supports the evaluation kit for the FAN6765MR.This document describes a 65W power supply using FAN6756MR. The FAN6756MR mWSaver™ controller targets power adapters that demand extremely low standby power consumption. With innovative mWSaver™ technology, FAN6756MR dramatically reduces standby and no-load power consumption. The AX-CAP™ technology minimizes losses in the EMI filter stage by eliminating the X-cap discharge resistors while meeting IEC61010-1 safety requirements. Standby Mode switches feedback impedance during Burst Mode operation, which forces the system to operate in a “Deep” Burst Mode with minimum switching losses. Proprietary asynchronous jitter decreases EMI emission and built-in synchronized slope compensation allows more stable Peak-Current-Mode control over a wide range of input voltage and load conditions.

FAN6765MR評估板指標:

FAN6765MR評估板主要特性:

 Single-Ended Topologies, such as Flyback and Forward Converters  mWSaver™ Technology
- Achieves Low No-Load Power Consumption: Less than 30mW at 230VAC (EMI Filter Loss Included)
- Eliminates X Capacitor Discharge Resistor Loss with AX-CAP™ Technology
- Linearly Decreases Switching Frequency to 23KHz
- Burst Mode Operation at Light-Load Condition
- Impedance Modulation in Standby Mode for “Deep” Burst Mode Operation
- Low Operating Current (450μA) in Standby Mode
- 500V High-Voltage JFET Startup Circuit to Eliminate Startup Resistor Loss
 Highly Integrated with Rich Features
- Proprietary Asynchronous-Jitter to Reduce EMI
- High-Voltage Sampling to Detect Input Voltage
- Peak-Current-Mode Control with Slope Compensation
- Cycle-by-Cycle Current Limiting with Line Compensation
- Leading Edge Blanking (LEB)
- Built-In 8ms Soft-Start
 Advanced Protections
- Brown-In/Brownout Recovery
- Internal Overload/Open-Loop Protection (OLP)
- VDD Under-Voltage Lockout (UVLO)
- VDD Over-Voltage Protection (VDD OVP)
- Over-Temperature Protection (OTP)
- Current-Sense Short-Circuit Protection (SSCP)

圖4.FAN6765MR評估板外形圖

圖5.FAN6765MR評估板電路圖

FAN6765MR評估板材料清單(BOM):



圖6.FAN6765MR評估板變壓器電路和指標圖

圖7.FAN6765MR評估板元件布局圖(頂層)

圖8.FAN6765MR評估板元件布局圖(底層)