Fairchild FSFA2100 service manual

FSFA2100 — Fairchild Power Switch (FPS™)

for Half-Bridge PWM Converters

FSFA2100 — Fairchild Power Switch (FPS

September 2008

Features

 Optimized for Complementary Driven Half-Bridge

Soft-Switching Converters

 Can be Applied to Various Topologies: Asymmetric

PWM Half-Bridge Converters, Asymmetric PWM Flyback Converters, Asymmetric PWM Forward Converters, Active Clamp Flyback Converters

 High Efficiency through Zero-Voltage-Switching (ZVS)  Internal SuperFET™s with Fast-Recovery Type

Body Diode (t

=120ns)

rr

 Fixed Dead Time (200ns) Optimized for MOSFETs  Up to 300kHz Operating Frequency  Internal Soft-Start  Pulse-by-Pulse Current Limit  Burst-Mode Operation for Low Standby Power

Consumption

 Protection Functions: Over-Voltage Protection

(OVP), Over-Load Protection (OLP), Abnormal Over-Current Protection (AOCP), Internal Thermal Shutdown (TSD)

Applications

 PDP and LCD TVs  Desktop PCs and Servers  Adapters  Telecom Power Supplies

Description

The growing demand for higher power density and low profile in power converter designs has forced designers to increase switching frequencies. Operation at higher frequencies considerably reduces the size of passive components, such as transformers and filters. However, switching losses have been an obstacle to highfrequency operation. To reduce switching losses and allow high-frequency operation, Pulse Width Modulation (PWM) with soft-switching techniques have been developed. These techniques allow switching devices to be softly commutated, which dramatically reduces the switching losses and noise.

FSFA2100 is an integrated PWM controller and SuperFET™ specifically designed for Zero-VoltageSwitching (ZVS) half-bridge converters with minimal external components. The internal controller includes an oscillator, under-voltage-lockout, leading-edge blanking (LEB), optimized high-side and low-side gate driver, internal soft-start, temperature-compensated precise current sources for loop compensation and selfprotection circuitry. Compared with discrete MOSFET and PWM controller solution, FSFA2100 can reduce total cost; component count, size, and weight; while simultaneously increasing efficiency, productivity, and system reliability.

™

) for Half-Bridge PWM Converter

Ordering Information

Part

Number

FSFA2100

Notes:

1. The junction temperature can limit the maximum output power.

2. Maximum practical continuous power in an open-frame design at 50°C ambient.

For Fairchild’s definition of “green” Eco Status, please visit: http://www.fairchildsemi.com/company/green/rohs_green.html.

Operating

Junction

Temperature

-40 to +130°C

R

DS(ON_MAX)

0.38Ω

Maximum Output

Power without

Heatsink

=350~400V)

(V

IN

200W 450W 9-SIP

(1,2)

Maximum Output

Power with Heatsink

=350~400V)

(V

IN

(1,2)

Package

Eco

Status

RoHS

Application Circuit Diagram

FSFA2100 — Fairchild Power Switch (FPS™) for Half-Bridge PWM Converter

Ns

D1

D2

KA431

V

O

R

C

F

C

B

L

lk

Np

V

CC

C

DL

V

IN

LVcc

R

T

V

Control

FB

V

DL

Lm

HVcc

IC

V

CTR

CS

SG PG

R

sense

Figure 1. Typical Application Circuit for an Asymmetric PWM Half-Bridge Converter

C

B

Ns

D1

V

O

L

lk

Np

V

CC

LVcc

R

T

V

DL

Lm

HVcc

FB

sense

Control

IC

SG PG

V

CTR

R

C

F

KA431

C

DL

V

IN

V

CS

R

Figure 2. Typical Application Circuit for an Asymmetric PWM Flyback Converter

Block Diagram

FSFA2100 — Fairchild Power Switch (FPS™) for Half-Bridge PWM Converter

Figure 3. Internal Block Diagram

Pin Configuration

1 2 3 4 5 6 7 8 9 10

CSSGPG

LVcc

HVcc

V

DL

R

T

V

FB

Figure 4. Package Diagram

FSFA2100 — Fairchild Power Switch (FPS™) for Half-Bridge PWM Converter

V

CTR

Pin Definitions

Pin # Name Description

1 VDL This is the drain of the high-side MOSFET, typically connected to the input DC link voltage.

2 VFB

3 RT This pin programs the switching frequency using a resistor.

4 CS

5 SG This pin is the control ground.

6 PG This pin is the power ground. This pin is connected to the source of the low-side MOSFET.

7 LVCC This pin is the supply voltage of the control IC.

8 NC No connection.

9 HVCC This is the supply voltage of the high-side gate-drive circuit IC.

10 V

CTR

This pin is connected to the inverting input of the PWM comparator internally and to the opto-coupler externally. The duty cycle is determined by the voltage on this pin.

This pin senses the current flowing through the low-side MOSFET. Typically, negative voltage is applied on this pin.

This is the drain of the low-side MOSFET. Typically, a transformer is connected to this pin.

FSFA2100 — Fairchild Power Switch (FPS™) for Half-Bridge PWM Converter

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. T

Symbol Parameter Min. Max. Unit

VDS Maximum Drain-to-Source Voltage (VDL-V

LVCC Low-Side Supply Voltage -0.3 25.0 V

HVCC to V

HVCC High-Side Floating Supply Voltage -0.3 625.0 V

VFB Feedback Pin Input Voltage -0.3 LVCC V

VCS Current Sense (CS) Pin Input Voltage -5.0 1.0 V

VRT R

dV

CTR

PD Total Power Dissipation

TJ

T

MOSFET Section

V

DGR

VGS Gate Source (GND) Voltage ±30 V

IDM Drain Current Pulsed 33 A

Package Section

Torque Recommended Screw Torque 5~7 kgf·cm

Notes:

3. Per MOSFET when both MOSFETs are conducting.

4. The maximum value of the recommended operating junction temperature is limited by thermal shutdown.

High-Side VCC Pin to Low-Side Drain Voltage -0.3 25.0 V

CTR

Pin Input Voltage -0.3 5.0 V

T

/dt Allowable Low-Side MOSFET Drain Voltage Slew Rate 50 V/ns

(3)

12.0 W

Maximum Junction Temperature

(4)

Recommended Operating Junction Temperature

Storage Temperature Range -55 +150

STG

Drain Gate Voltage (RGS=1MΩ)

ID Continuous Drain Current

=25°C unless otherwise specified.

A

and V

CTR

+150

(4)

) 600 V

CTR-PG

-40 +130

°C

600 V

TC=25°C

T

=100°C

C

11

7

A

Thermal Impedance

TA=25°C unless otherwise specified.

Symbol Parameter Value Unit

θJC Junction-to-Case Center Thermal Impedance (Both MOSFETs Conducting) 10.44 ºC/W