Document
FS7M0680, FS7M0880
Fairchild Power Switch (FPSTM)
www.fairchildsemi.com
Features
• Pulse by Pulse Current Limit • Over load protection (OLP) - Latch • Over voltage protection (OVP) - Latch • Internal Thermal Shutdown (TSD) - Latch • Under Voltage Lock Out (UVLO) with hysteresis • Internal High Voltage SenseFET (800V rated) • User defined Soft Start • Precision Fixed Operating Frequency (66kHz)
Application
• PC power supply • PDP
Table 1. Maximum Output Power
OUTPUT POWER TABLE
PRODUCT
230VAC ±15%(2) Open Frame(1)
85-265VAC Open Frame(1)
FS7M0680
80W (Flyback) 150W (Forward) 180W (Forward) (3)
65W (Flyback)
FS7M0880
110W (Flyback) 200W (Forward) 250W (Forward) (3)
85W (Flyback)
Notes: 1. Maximum practical continuous power in an open frame design at 50°C ambient. 2. 230 VAC or 100/115 VAC with doubler. 3. When the cooling fan is used.
Description
The Fairchild Power Switch FS7M-series is an integrated Pulse Width Modulator (PWM) and Sense FET specifically designed for high performance offline Switch Mode Power Supplies (SMPS) with minimal external components. This device is an integrated high voltage power switching regulator which combine an avalanche rugged Sense FET with a current mode PWM control block. The PWM controller includes integrated fixed frequency oscillator, under voltage lockout, leading edge blanking (LEB), optimized gate driver, soft start, temperature compensated precise current sources for a loop compensation and self protection circuitry. Compared with discrete MOSFET and PWM controller solution, it can reduce total cost, component count, size and weight simultaneously increasing efficiency, productivity, and system reliability. This device is a basic platform well suited for cost effective designs of flyback and forward converters.
Typical Circuit
AC IN FS7M-series
S/S
PWM
VFB Vcc
Drain GND
Vo
Figure 1. Typical Forward Application
©2005 Fairchild Semiconductor Corporation
Rev.1.0.2
FS7M0680, FS7M0880
Internal Block Diagram
Vcc 3
Soft start 5
Vref
9V/15V
Reset
Vcc good
Vref
OSC
FB 4
Vcc Idelay
Vref
IFB
2.5R R
VSD Vcc
Vovp TSD
PWM
SQ RQ
LEB
Vcc Reset (Vcc<6V)
SQ
RQ
AOCP
Drain 1
Internal Bias
Gate driver
Vocp
2 GND
Figure 2. Functional Block Diagram of FS7M0680 and FS7M0880
2
Pin Definitions
FS7M0680, FS7M0880
Pin Number 1 2 3
4
5
Pin Name Drain GND Vcc
Vfb
Soft-start
Pin Function Description
High voltage power SenseFET drain connection.
This pin is the control ground and the SenseFET source.
This pin is the positive supply input. This pin provides internal operating current for both start-up and steady-state operation.
This pin is internally connected to the 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 7.5V, the over load protection triggers resulting in shutdown of the FPS.
This pin is for the soft start. Soft start time is programmed by a capacitor on this pin.
Pin Configuration
TO-3P-5L
5.S/S 4.Vfb 3.Vcc 2.GND 1.Drain
Figure 3. Pin Configuration (Top View)
3
FS7M0680, FS7M0880
Absolute Maximum Ratings
FS7M0680 Parameter Maximum Drain Voltage (1) Drain-Gate Voltage (RGS=1MΩ) Gate-Source (GND) Voltage Drain Current Pulsed (2) Single Pulsed Avalanche Energy (3) Avalanche Current (4) Continuous Drain Current (TC=25°C) Continuous Drain Current (TC=100°C) Maximum Supply Voltage Input Voltage Range
Total Power Dissipation
Operating Ambient Temperature Storage Temperature
Symbol VD,MAX VDGR
VGS IDM EAS IAS ID ID VCC,MAX VFB PD Derating TA TSTG
Value 800 800 ±30 24.0 455 20 6.0 3.8 30 -0.3 to VSD 150 1.21 -25 to +85 -55 to +150
FS7M0880 Parameter Maximum Drain Voltage (1) Drain-Gate Voltage (RGS=1MΩ) Gate-Source (GND) Voltage Drain Current Pulsed (2) Single Pulsed Avalanche Energy (3) Avalanche Current (4) Continuous Drain Current (TC=25°C) Continuous Drain Current (TC=100°C) Maximum Supply Voltage Input Voltage Range
Total Power Dissipation
Operating Ambient Temperature Storage Temperature
Symbol VD,MAX VDGR
VGS IDM EAS IAS ID ID VCC,MAX VFB PD Derating TA TSTG
Note:
1. Tj = 25°C to 150°C 2. Repetitive rating: Pulse width limited by maximum junction temperature
3. L = 24mH, VDD = 50V, RG = 25Ω, starting Tj =25°C 4. L = 13µH, starting Tj = 25°C
Value 800 800 ±30 32.0 810 15 8.0 5.6 30 -0.3 to VSD 190 1.54 -25 to +85 -55 to +150
Unit V V V
ADC mJ A ADC ADC V V W W/°C °C °C
Unit V V V
ADC mJ A ADC ADC V V W W/°C °C °C
4
FS7M0680, FS7M0880
Electrical Characteristics (SenseFET Part)
(Ta=25°C unless otherwise specified)
FS7M0680 Parameter Drain-Source Breakdown Voltage
Zero Gate Voltage Drain Current
Static Drain-Source On Resistance (note1) Input Capacitance Output Capacitance Reverse Transfer Capacitance Turn On Delay Time Rise Time Turn Off Delay Time Fall Time Total Gate Charge (Gate-Source+Gate-Drain) Gate-Source Cha.