Power Switch. FSQ0565RQ Datasheet
Green-Mode Power Switch
for Quasi-Resonant Operation - Low EMI and High Efficiency
! Optimized for Quasi-Resonant Converters (QRC)
! Low EMI through Variable Frequency Control and AVS
(Alternating Valley Switching)
! High-Efficiency through Minimum Voltage Switching
! Narrow Frequency Variation Range over Wide Load
and Input Voltage Variation
! Advanced Burst-Mode Operation for Low Standby
! Simple Scheme for Sync Voltage Detection
! Pulse-by-Pulse Current Limit
! Various Protection Functions: Overload Protection
(OLP), Over-Voltage Protection (OVP), Internal
Thermal Shutdown (TSD) with Hysteresis,
Output Short Protection (OSP)
! Under-Voltage Lockout (UVLO) with Hysteresis
! Internal Startup Circuit
! Internal High-Voltage Sense FET (650V)
! Built-in Soft-Start (17.5ms)
! Power Supply for LCD TV and Monitor, VCR, SVR,
STB, and DVD & DVD Recorder
A Quasi-Resonant Converter (QRC) generally shows
lower EMI and higher power conversion efficiency than a
conventional hard-switched converter with a fixed
switching frequency. The FSQ-series is an integrated
Pulse-Width Modulation (PWM) controller and
SenseFET specifically designed for quasi-resonant
operation and Alternating Valley Switching (AVS). The
PWM controller includes an integrated fixed-frequency
oscillator, Under-Voltage Lockout (UVLO), Leading-
Edge Blanking (LEB), optimized gate driver, internal soft-
start, temperature-compensated precise current sources
for a loop compensation, and self-protection circuitry.
Compared with a discrete MOSFET and PWM controller
solution, the FSQ-series can reduce total cost,
component count, size, and weight; while simultaneously
increasing efficiency, productivity, and system reliability.
This device provides a basic platform for cost-effective
designs of quasi-resonant switching flyback converters.
© 2008 Semiconductor Components Industries, LLC.
October-2017, Rev. 3
Publication Order Number:
Maximum Output Power(1)
-25 to +85°C
-25 to +85°C
1. The junction temperature can limit the maximum output power.
2. 230VAC or 100/115VAC with doubler.
3. Typical continuous power in a non-ventilated enclosed adapter measured at 50°C ambient temperature.
4. Maximum practical continuous power in an open-frame design at 50°C ambient.
5. Eco Status, RoHS
FSQ0565RS Rev. 00
Figure 1. Typical Flyback Application