Fairchild SG6858 Low-Cost, Green-Mode PWM Controller Data Sheet for Flyback Converters
Summary
Optimize your consumer electronics designs with this highly integrated PWM Controller for Flyback Converters. Featuring proprietary Green-Mode technology, it ensures exceptional power efficiency, critically lowering standby consumption to meet stringent Blue Angel standards. The chip provides constant output limits and robust protection schemes while simplifying complex SMPS builds. It is essential for engineers developing reliable power solutions, including battery chargers, adapters, open-frame supplies, and LED drivers across various home appliances.
Page 1 Text Content
SG 6858 — Low -C ost, G reen-M ode, PW ontroller for Flyback C onverters
September 2009
SG6858 Low-Cost, Green-Mode, PWM Controller for Flyback Converters Features Description
Green-Mode PWM This highly integrated PWM controller provides several special enhancements designed to meet the low
Supports the ”Blue Angel” Standard
standby-power needs of low-power SMPS. To minimize standby power consumption, the proprietary green-
Low Startup Current: 10µA (Maximum)
mode function provides off-time modulation to linearly
Low Operating Current: 2.5m A decrease the switching frequency under light-load
conditions. This green-mode function enables the
Leading-Edge Blanking (LEB)
power supply to meet even the strictest power
Constant Output Power Limit conservation requirements. Built-in Synchronized Slope Compensation The Bi CMOS fabrication process enables reducing the
startup current to 10µA and the operating current to
Current-Mode Operation
2.5m A. To further improve power conservation, a large
Cycle-by-Cycle Current Limiting startup resistance can be used. Built-in synchronized
slope compensation ensures the stability of peak-
Under-Voltage Lockout (UVLO)
current-mode control. Proprietary internal compensation
Programmable PWM Frequency provides a constant output power limit over a universal
AC input range (90VAC to 264VAC). Pulse-by-pulse
VDD Over-Voltage Protection with Auto-Restart
current limiting ensures safe operation even during Gate Output Voltage Clamped at 17V short circuits.
Few External Components Required To protect the external power MOSFET from being
damaged by supply over voltage, the output driver is
SSOT-26 and DIP-8 Packages Available
clamped at 17V. SG6858 controllers can improve the performance and reduce the production cost of power Applications supplies. The SG6858 replaces linear and RCC-mode power adapters. It is available in 8-pin DIP and 6-pin Battery chargers for cellular phones, cordless SSOT-26 packages.
phones, PDAs, digital cameras, and power tools Power adapters for ink jet printers, video game consoles, and portable audio players Open-frame SMPS for TV/DVD standby and other auxiliary supplies, home appliances, PC 5V standby power, and consumer electronics Replacements for linear transformers and RCC SMPS Offline High Brightness (HB) LED drivers
Ordering Information
Part Number Operating Temperature Range Eco Status Package Packing Method
SG6858TZ -40 to +125°C Ro HS 6-Pin SSOT-26 Tape & Reel SG6858DZ -40 to +125°C Ro HS 8-Pin DIP-8 Tube
For Fairchild’s definition of Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com SG6858 • Rev. 1.2.4
Page Summary Contents For Fairchild SG6858 Low-Cost, Green-Mode PWM Controller Data Sheet for Flyback Converters
Manual Details
| Brand | Fairchild |
|---|---|
| Pages | 13 |
| File Size | 476.31 KB |
| Published | June 06, 2026 |
Enter the captcha to get the download link:
Frequently Asked Questions
How does the SG6858 minimize standby power consumption?
The Green-Mode PWM feature uses off-time modulation to decrease switching frequency under light-load conditions, meeting low-power SMPS standards.
What control method is used to implement constant output power limits?
Programmable PWM Frequency and Pulse-by-pulse AC current limiting ensure a steady output power limit over a wide AC input range (90V to 264V).
Which pins are utilized for sensing and monitoring operation?
The SENSE pin activates over-current protection, while the RI pin controls switching frequency using an external resistor.
What types of applications can this controller replace?
It is designed to replace linear transformers and traditional RCC-mode SMPS in various consumer electronics and chargers.