Fairchild FSQ500L service manual
April 2012
FSQ500L
Compact, Green Mode, Fairchild Power Switch (FPS™)
FSQ500L — Compact, Green Mode, Fairchild Power Switch (FPS™)
Features
Single Chip 700V SenseFET Power Switch
Precision Fixed Operating Frequency: 130kHz
No-load consumption 250mW at 265V
Burst Mode and Down to 60mW with External Bias
AC
with
Internal Startup Switch
Soft-Start Time Tuned by External Capacitor
Under-Voltage Lockout (UVLO) with Hysteresis
Pulse-by-Pulse Current Limit
Overload Protection (OLP) and Internal Thermal
Shutdown Function (TSD) with Hysteresis
Auto-Restart Mode
No Need for Auxiliary Bias Winding
Applications
Cost-Effective Linear Power Supplies Replacement
Charger and Adapter for Mobile Phone, PDA, MP3,
and Cordless Phone
Related Resources
AN4137 — Design Guidelines for Off-line Flyback
Converters Using Fairchild Power Switch (FPS™)
AN4141 — Troubleshooting and Design Tips for
Fairchild Power Switch (FPS™) Flyback
Applications
AN-4147 — Design Guidelines for RCD Snubber of
Flyback Converters
AN-6075 — Compact Green Mode Adapter Using
FSQ500L for Low Cost
AN-4138 — Design Considerations for Battery
Charger Using Green Mode Fairchild Power Switch
(FPS™)
Evaluation Board: FEBFSQ500L_H257v1
Description
The FSQ500L is specially designed for a replacement of
linear power supplies with low cost. This device
combines current-mode Pulse Width Modulator (PWM)
with a senseFET. The integrated PWM controller
features include: a fixed oscillator, Under Voltage
Lockout (UVLO) protection, Overload Protection (OLP),
Leading-Edge Blanking (LEB), an optimized gate turnon/turn-off driver, Thermal Shutdown (TSD) protection
with hysteresis, and temperature-compensated
precision-current sources for loop compensation. When
compared to a linear power supply, the FSQ500L device
reduces total size and weight, while increasing
efficiency, productivity, and system reliability. This
device provides a basic platform for cost-effective
flyback converters.
Maximum Output Power
230VAC ± 15%
Adapter
Notes:
1. The junction temperature can limit the maximum
2. 230V
3. Typical continuous power in a non-ventilated
4. Maximum practical continuous power in an open
(3)
2.5W 3.0W 2.0W 2.5W
output power.
or 100/115VAC with doubler.
AC
enclosed adapter measured at 50°C ambient.
frame design at 50°C ambient.
(2)
85-265VAC
Open
Frame
(4)
Adapter
(1)
Open
(3)
Frame
(4)
Ordering Information
Part Number
FSQ500L -40°C to +85°C 4-Lead, Small Outline Package (SOT223-4L) Tape & Reel
© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com
FSQ500L • Rev. 1.0.3
Operating
Temperature Range
Package Packing Method
Application Circuit Diagram
AC
IN
Figure 1. Typical Application Circuit
FB
PWM
FSQ500L — Compact, Green Mode, Fairchild Power Switch (FPS™)
DC
OUT
D
GNDV
V
CC
Internal Block Diagram
V
3
FB
V
V
V
VSD
V
CC
BURL/VBURH
I
I
DELAY
CC
OLP
OLP
FB
I
(BURST MODE:IFB/2)
8R
R
Soft-Soft
OSC
S
Q
A/R
R
TSD
Figure 2. Internal Block Diagram
7.7V
S
Q
R
HV/REG OFF
V
CC
2
6.5V
HV/REG
Z
V
REF
UVLO
D
1
250ns
LEB
R
sense
(0.3V)
4
GND
© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com
FSQ500L • Rev. 1.0.3 2
Pin Assignments
Pin Definitions
GND
FSQ500L
V
CC VFBD
Figure 3. Package / Pin Diagram
FSQ500L — Compact, Green Mode, Fairchild Power Switch (FPS™)
Pin # Name Description
High-voltage power senseFET drain connection. In addition, at startup, the internal high-voltage
current source supplies internal bias and charges the external capacitor connected to the V
1 D
2 VCC
3 VFB
4 GND This pin is the control ground and the senseFET source.
Once V
is alive until V
irregularly to maintain V
This pin is connected to a storage capacitor. A high-voltage regulator connected between pin 1 (D)
and this pin provides the supply voltage to the FSQ500L at startup and when switching during
normal operation. The FSQ500L eliminates the need for auxiliary bias winding and associated
external components.
This pin is internally connected to the non-inverting input of the PWM comparator. The collector of
an opto-coupler is typically tied to this pin. For stable operation, a capacitor should be placed
between this pin and GND. If the voltage of this pin reaches 4.5V, the overload protection triggers,
which shuts down the FPS.
reaches 6.0V, all internal blocks are activated. The internal high-voltage current source
CC
reaches 6.5V. After that, the internal high voltage current source turns on and off
CC
at 6.5V.
CC
CC
pin.
© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com
FSQ500L • Rev. 1.0.3 3
Absolute Maximum Ratings
Stresses exceeding the absolute maximum ratings may damage the device. The device may not function or be
operable above the recommended operating conditions and stressing the parts to these levels is not recommended.
In addition, extended exposure to stresses above the recommended operating conditions may affect device reliability.
The absolute maximum ratings are stress ratings only.
Symbol Parameter Min. Max. Unit
VDS Drain Pin Voltage
VCC Supply Voltage 10 V
VFB Feedback Voltage Range -0.3 VCC V
PD Total Power Dissipation 0.78 W
IDM Drain Current Pulsed
TJ Operating Junction Temperature -40 Internally Limited
T
Storage Temperature -55 +150
STG
Notes:
5. LDMOS available drain voltage is -0.3V ~ 700V.
6. Repetitive rating: pulse width is limited by maximum junction temperature.
(5)
700 V
(6)
0.41 A
°C
°C
FSQ500L — Compact, Green Mode, Fairchild Power Switch (FPS™)
Thermal Impedance
Symbol Parameter Value Unit
θJA Junction-to-Ambient Thermal Resistance
Note:
7. Free-standing with no heat sink; minimum land pattern.
(7)
+160 °C/W
© 2008 Fairchild Semiconductor Corporation www.fairchildsemi.com
FSQ500L • Rev. 1.0.3 4
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