Document
FSQ0365/0265/0165/321 — Green Mode Fairchild Power Switch (FPS™) for Valley Switching Converter
August 2011
FSQ0365, FSQ0265, FSQ0165, FSQ321 Green Mode Fairchild Power Switch (FPS™)
for Valley Switching Converter – Low EMI and High Efficiency
Features
Optimized for Valley Switching Converter (VSC) Low EMI through Variable Frequency Control and
Inherent Frequency Modulation
High Efficiency through Minimum Voltage Switching Narrow Frequency Variation Range Over Wide Load
and Input Voltage Variation
Advanced Burst-Mode Operation for Low Standby
Power Consumption
Pulse-by-Pulse Current Limit Protection Functions: Overload Protection (OLP),
Over-Voltage Protection (OVP), Abnormal OverCurrent Protection (AOCP), Internal Thermal Shutdown (TSD)
Under-Voltage Lockout (UVLO) with Hysteresis Internal Startup Circuit Internal High-Voltage SenseFET: 650V Built-in Soft-Start: 15ms
Applications
Power Supplies for DVP Player, DVD Recorder,
Set-Top Box
Adapter Auxiliary Power Supply for PC, LCD TV, and PDP TV
Description
A Valley Switching Converter 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 valley switching operation with minimal external components. The PWM controller includes an integrated fixed-frequency oscillator, under-voltage lockout, Leading-Edge Blanking (LEB), optimized gate driver, internal soft-start, temperature-compensated precise current sources for loop compensation, and self-protection circuitry.
Compared with discrete MOSFET and PWM controller solutions, the FSQ-series reduces 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 valley switching fly-back converters.
Related Application Notes
AN-4137 - Design Guidelines for Offline Flyback
Converters Using Fairchild Power Switch (FPS™)
AN-4141 - Troubleshooting and Design Tips for
Fairchild Power Switch (FPS™) Flyback Applications
AN-4147 - Design Guidelines for RCD Snubber of
Flyback Converters
AN-4150 - Design Guidelines for Flyback
Converters Using FSQ-series Fairchild Power Switch (FPS™)
AN-4134 - Design Guidelines for Off-line Forward
Converters Using Fairchild Power Switch (FPS™)
© 2007 Fairchild Semiconductor Corporation FSQ0365, FSQ0265, FSQ0165, FSQ321 • Rev. 1.0.6
www.fairchildsemi.com
FSQ0365/0265/0165/321 — Green Mode Fairchild Power Switch (FPS™) for Valley Switching Converter
Ordering Information
Part Number FSQ321
Package 8-DIP
Maximum Output Table(1)
Operating Current RDS(ON) 230VAC ±15%(2)
85-265VAC
Temperature
Limit
(Max.) Adapter(3)
Open Frame(4)
Adapter(3)
Open Frame(4)
Replaces Devices
FSQ321L FSQ321LX
8-LSOP
8-LSOP (Tape &
Reel)
-40 to +85°C
0.6A
19Ω
8W
12W
7W
10W
FSDL321 FSDM311
FSQ0165RN 8-DIP
FSQ0165RL FSQ0165RLX
8-LSOP
8-LSOP (Tape &
Reel)
-40 to +85°C
0.9A
10Ω
10W
15W
9W 13W FSDL0165RN
FSQ0265RN FSQ0265RL
8-DIP 8-LSOP
-40 to +85°C
1.2A
6Ω
14W
20W
11W
16W
FSDM0265RN FSDM0265RNB
FSQ0365RN 8-DIP -40 to +85°C 1.5A
FSQ0365RL 8-LSOP
4.5Ω
17.5W
25W
13W
19W
FSDM0365RN FSDM0365RNB
Notes: 1. The junction temperature can limit the maximum output power. 2. 230VAC or 100/115VAC with voltage doubler. The maximum power with CCM operation 3. Typical continuous power in a non-ventilated, enclosed adapter measured at 50C ambient temperature.
4. Maximum practical continuous power in an open-frame design at 50C ambient temperature.
© 2007 Fairchild Semiconductor Corporation FSQ0365, FSQ0265, FSQ0165, FSQ321 • Rev. 1.0.6
2
www.fairchildsemi.com
FSQ0365/0265/0165/321 — Green Mode Fairchild Power Switch (FPS™) for Valley Switching Converter
Application Circuit
AC IN
Sync
PWM
Vfb Vcc
Vstr Drain
GND
Vo
Figure 1. Typical Flyback Application
Internal Block Diagram
Sync 4
Vfb 3
0.7V/0.2V
+
0.35/0.55
VCC
Vref
VBurst
-
Idelay
IFB
3R
R
SoftStart
+ -
PWM
Vstr Vcc Drain 5 2 678
OSC
Vref VCC Good
+
8V/12V
LEB 200ns
SQ RQ
Gate Driver
6V VSD
Sync 6V
Vovp
TSD 2.5 s Time
Delay
VCC Good
SQ RQ
AOCP
Figure 2. Internal Block Diagram
VOCP (1.1V)
1 GND
FSQ0365RN Rev.00
© 2007 Fairchild Semiconductor Corporation FSQ0365, FSQ0265, FSQ0165, FSQ321 • Rev. 1.0.6
3
www.fairchildsemi.com
FSQ0365/0265/0165/321 — Green Mode Fairchild Power Switch (FPS™) for Valley Switching Converter
Pin Assignments
Figure 3. Pin Configuration (Top View)
Pin Definitions
Pin#
1
Name
GND
2 VCC
3 Vfb
4 Sync
5 6, 7, 8
Vstr Drain
Description
SenseFET source terminal on primary side and internal control ground.
Positive supply voltage input. Although connected to an auxiliary transformer winding, current is suppli.