SG6860 Datasheet, PDF (1/11 Pages) Fairchild Semiconductor – Low-Cost, Green-Mode PWM Controller for Flyback Converters

March 2008
SG6860
Low-Cost, Green-Mode PWM Controller for
Flyback Converters
Features
ƒ Green-Mode PWM
ƒ Supports the “Blue Angel” Eco Standard
ƒ Low Start-up Current: 9µA
ƒ Low Operating Current: 3mA
ƒ Leading-Edge Blanking
ƒ Constant Output Power Limit
ƒ Universal Input
ƒ Built-in Synchronized Slope Compensation
ƒ Current Mode Operation
ƒ Cycle-by-cycle Current Limiting
ƒ Under-Voltage Lockout (UVLO)
ƒ Programmable PWM Frequency with Frequency
Hopping
ƒ VDD Over-Voltage Protection (Latch off)
ƒ Gate Output Voltage Clamped at 17V
ƒ Low Cost
ƒ Few External Components Required
ƒ Small SOT-26 Package
Applications
ƒ Power Adaptors
ƒ Open-Frame SMPS
Description
This highly integrated PWM controller provides several
enhancements designed to meet the low standby-power
needs of low-power SMPS. To minimize standby power
consumption, a proprietary green-mode function
provides off-time modulation to linearly decrease the
switching frequency under light-load conditions. This
green-mode function enables the power supply to meet
even strict power conservation requirements.
The BiCMOS fabrication process enables reducing the
start-up current to 9µA and the operating current to
3mA. To further improve power conservation, a large
start-up resistance can be used. Built-in synchronized
slope compensation ensures the stability of peak
current mode control. Proprietary internal compensation
provides a constant output power limit over a universal
AC input range (90VAC to 264VAC). Pulse-by-pulse
current limiting ensures safe operation even during
short-circuits.
To protect the external power MOSFET from being
damaged by supply over voltage, the SG6860’s output
driver is clamped at 17V. SG6860 controllers can
improve the performance and reduce the production
cost of power supplies. The SG6860 can replace linear
and RCC-mode power adapters. It is available in 8-pin
DIP and 6-pin SOT-26 packages.
Ordering Information
Part Number
SG6860TZ
SG6860DZ
Operating Temperature Range
Package
-40°C to +85°C
Small SOT-26 Package
-40°C to +85°C
8-pin Dual in-line Package (DIP)
Packing Method
Tape & Reel
Rail
All packages are lead free per JEDEC: J-STD-020B standard.
© 2008 Fairchild Semiconductor Corporation
SG6860 • Rev. 1.0.1
www.fairchildsemi.com