Fairchild Fan6747WL Data Handbook

6747W ig ly In teg rated reen -M e P tro ller

May 2012

FAN6747WL Highly Integrated Green-Mode PWM Controller

Features Description

 High-Voltage Startup The highly integrated FAN6747WL PWM controller provides several features to enhance the performance

 AC-Line Brownout Protection by HV Pin

of flyback converters. To minimize standby power  Constant Output Power Limit by HV Pin consumption, a proprietary Green-Mode function provides off-time modulation to decrease the switching

(Full AC-Line Range)

frequency with load condition.

 Built-in 8ms Soft-Start Function

Under zero-load condition, the power supply enters

 Two-Level Over-Current Protection (OCP) with

Burst Mode and burst frequency can be low to reduce

215ms Debounce

power. Green Mode enables the power supply to meet  Short-Circuit Protection (SCP) with 15ms Debounce international power conservation requirements.

as Output Short

The FAN6747WL is specially designed for SMPS with  Peak-Current Mode Operation with Cycle-by-Cycle peak-current output. It incorporates a cycle-by-cycle Current Limiting current limiting and two-level Over-Current-Protection (OCP) that can handle peak load with a debounce time.

 Low Startup Current: 30µA

Once the current is over the threshold level, it triggers  Low Operating Current: 1.7m A the first counter 15ms and checks if VDD is below 10V; if it is, the PWM latches off for SCP. If VDD is higher than

 Over-Temperature Protection (OTP) with External

10V; it keeps counting to 215ms, then the PWM latches

Negative-Temperature-Coefficient (NTC) Thermistor

off for OCP.

 PWM Frequency Decreasing at Green-Mode

FAN6747WL also integrates a frequency-hopping  VDD Over-Voltage Protection (OVP) function that helps reduce EMI emission of a power supply with minimum line filters. The built-in

 Internal Latch Circuit for OVP, OTP, SCP, and OCP

synchronized slope compensation helps achieve stable peak-current control. To keep constant output power Applications limit over universal AC input range, the current limit and OCP threshold voltage are adjusted according to AC

General-purpose switch-mode power supplies and

line voltage detected by the HV pin. The gate output is

flyback power converters, including:

clamped at 13.5V to protect the external MOSFET from over-voltage damage.

 Power Adapters

Other protection functions include AC-line brownout

 SMPS with Peak-Current Output, such as for

protection with hysteresis and VDD over-voltage

Printers, Scanners, Motor Drivers

protection. For over-temperature protection, an external  AC/DC NB Adapters NTC thermistor is applied to sense the ambient temperature. When OCP, OVP, SCP, or OTP is

 Open-Frame SMPS

activated, an internal circuit latches off the controller. The latch is reset when VDD drops to VDD-LH.

Ordering Information

Operating

Part Number Package Packing Method

Temperature Range

8-Lead, Small-Outline Integrated Circuit (SOIC),

FAN6747WLMY -40 to +105°C Tape & Reel

JEDEC MS-012, .15-Inch Narrow Body

© 2012 Fairchild Semiconductor Corporation www.fairchildsemi.com FAN6747WL • Rev. 1.0.1