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SG6742HR_HL Datasheet, PDF (1/13 Pages) Fairchild Semiconductor – Highly Integrated Green-Mode PWM Controller | |||
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April 2009
SG6742HL/HR
Highly Integrated Green-Mode PWM Controller
Features
 High-Voltage Startup
 Low Operating Current: 2.7mA
 Linearly Decreasing PWM Frequency to 22KHz
 Frequency Hopping to Reduce EMI Emission
 Fixed PWM Frequency: 100KHz
 Peak-Current-Mode Control
 Cycle-by-Cycle Current Limiting
 Leading-Edge Blanking (LEB)
 Synchronized Slope Compensation
 Internal Open-Loop Protection
 GATE Output Maximum Voltage Clamp: 18V
 VDD Under-Voltage Lockout (UVLO)
 VDD Over-Voltage Protection (OVP)
 Programmable Over-Temperature Protection (OTP)
 Internal Latch Circuit (OVP, OTP)
 Internal-Sense, Short-Circuit Protection
 Built-in 6ms Soft-Start Function
 Constant Power Limit (Full AC Input Range)
 Internal OTP Sensor with Hysteresis
Applications
General-purpose switch-mode power supplies and
flyback power converters, including:
 Power Adapters
 Open-Frame SMPS
Description
The highly integrated SG6742HL/HR PWM controller
provides several features to enhance the performance
of flyback converters.
To minimize standby power consumption, a proprietary
green-mode function provides off-time modulation to
linearly decrease the switching frequency at light-load
conditions. To avoid acoustic-noise problems, the
minimum PWM frequency is set above 22KHz. This
green-mode function enables the power supply to meet
international power conservation requirements. With the
internal high-voltage startup circuitry, the power loss
due to bleeding resistors is eliminated. To further
reduce power consumption, SG6742HL/HR is
manufactured using the BiCMOS process, which allows
an operating current of 2.7mA.
SG6742HL/HR integrates a frequency-hopping function
internally that helps reduce EMI emission of a power
supply with minimum line filters. Its built-in synchronized
slope compensation achieves stable peak-current-mode
control. The proprietary, internal line compensation
ensures constant output power limit over a wide AC
input voltage range, from 90VAC to 264VAC.
SG6742HL/HR provides many protection functions. In
addition to cycle-by-cycle current limiting, the internal
open-loop protection circuit ensures safety should an
open-loop or output short-circuit failure occur. PWM
output is disabled until VDD drops below the UVLO lower
limit, when the controller starts up again. As long as VDD
exceeds ~25V, the internal OVP circuit is triggered.
SG6742HL/HR is available in an 8-pin SOP package.
Ordering Information
Part
Number
SG6742HLSY
SG6742HRSY
Operating
Temperature
Range
-40 to +105°C
-40 to +105°C
OLP
Function
Package
Eco Packing
Status Method
Latch 8-Lead Small Outline Package (SOP)
Restart 8-Lead Small Outline Package (SOP)
Green
Green
Tape & Reel
Tape & Reel
For Fairchildâs definition of âgreenâ Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.
© 2008 Fairchild Semiconductor Corporation
SG6742HL/HR ⢠Rev. 1.0.4
www.fairchildsemi.com
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