Fairchild FSQ211 service manual

FSQ211 Green Mode Fairchild Power Switch (FPS

FSQ211 ⎯ Green Mode Fairchild Power Switch (FPS

April 2007

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Features

 Internal Avalanche-Rugged SenseFET  Precision Fixed Operating Frequency (67KHz)  Burst-Mode Operation  Internal Start-up Circuit  Pulse-by-Pulse Current Limiting  Overload Protection (OLP)  Internal Thermal Shutdown Function (TSD)  Auto-Restart Mode  Under-Voltage Lockout (UVLO) with Hysteresis  Built-in Soft-Start  Secondary-Side Regulation

Applications

 Charger & Adapter for Mobile Phone, PDA, & MP3  Auxiliary Power for White Goods, PC, C-TV, &

Monitor

Related Application Notes  AN-4137 Design Guidelines for Off-line Flyback

Converters using FPS™

 AN-4141 Troubleshooting and Design Tips for

Fairchild Power Switch (FPS™) Flyback Applications

 AN-4147 Design Guidelines for RCD Snubber of

Flyback

 AN-4134Design Guidelines for Off-line Forward

Converters using FPS™

 AN-4138Design Considerations for Battery Charger

Using Green Mode Fairchild Power Switch (FPS™)

Description

The FSQ211 consists of an integrated Pulse Width Modulator (PWM) and SenseFET, specifically designed for high-performance, off-line Switch Mode Power Supplies (SMPS) with minimal external components. This device is an integrated high-voltage power switching regulator that combines a VDMOS SenseFET with a voltage mode PWM control block. The integrated PWM controller features include a fixed oscillator, Under Voltage Lockout (UVLO) protection, Leading Edge Blanking (LEB), an optimized gate turn-on/turn-off driver, Thermal Shutdown (TSD) protection, and temperature compensated precision-current sources for loop compensation and fault protection circuitry.

When compared to a discrete MOSFET and controller or RCC switching converter solution, the FSQ211 device reduces total component count and design size and weight, while increasing efficiency, productivity, and system reliability. This device provides a basic platform well suited for cost-effective flyback converters.

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Ordering Information

Part Number Package Top Mark BV

FSQ211 8DIP

FSQ211L 8LSOP

FPSTM is a trademark of Fairchild Semiconductor Corporation

Q211

Q211L

f

DSS

650V 67KHz

R

OSC

DS(ON)

18Ω

Typical Application

AC

IN

Drain

Vstr

PWM

FSQ211 ⎯ Green Mode Fairchild Power Switch (FPS

DC

OUT

Internal Block Diagram

Vfb Vcc

Figure 1. Typical Flyback Application

GND

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Figure 2. Functional Block Diagram of FSQ211

Pin Assignments

FSQ211 ⎯ Green Mode Fairchild Power Switch (FPS

1

2

Vcc

Vfb

3

45

NC

Drain

8GND

Drain

7

6

Drain

Vstr

Figure 3. Pin Configuration (Top View)

Pin Definitions

Pin Name Description

1

2

3

4

5

6,7,8 Drain

GND

V

CC

V

FB

NC

Vstr

Ground. SenseFET source terminal on primary side and internal control ground. Positive supply voltage input. Although connected to an auxiliary transformer winding,

current is supplied from pin 5 (Vstr) via an internal switch during startup (see Block Diagram). It

is not until V

reaches the UVLO upper threshold (9V), that the internal start-up switch opens

CC

and device power is supplied via the auxiliary transformer winding.

Feedback. Inverts input to the PWM comparator with its normal input level between 0.5V and

2.5V. It has a 0.4mA current source connected internally, while a capacitor and opto-coupler are typically connected externally. A feedback voltage of 4.5V triggers overload protection (OLP). There is a time delay while charging external capacitor C internal 5µA current source. This time delay prevents false triggering under transient conditions, but allows the protection mechanism to operate under true overload conditions.

No Connection. Start-up. This pin connects directly to the rectified AC line voltage source. At start-up, the

internal switch supplies internal bias and charges an external storage capacitor placed between the VCC pin and ground. Once the VCC reaches 9V, the internal switch stops charging the capacitor.

SenseFET Drain. The drain pins are designed to connect directly to the primary lead of the

transformer and are capable of switching a maximum of 650V. Minimizing the length of the trace connecting these pins to the transformer decreases leakage inductance.

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from 3V to 4.5V using an

FB

FSQ211 ⎯ Green Mode Fairchild Power Switch (FPS

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 Value Unit

V

Drain Pin Voltage 650 V

DRAIN

V

Vstr Pin Voltage 650 V

STR

VDG Drain-Gate Voltage 650 V

VGS Gate-Source Voltage

VCC Supply Voltage 20 V

VFB Feedback Voltage Range -0.3 to V

PD Total Power Dissipation 1.40 W

TJ Operating Junction Temperature Internally limited °C

TA Operating Ambient Temperature -25 to +85 °C

T

Storage Temperature -55 to +150 °C

STG

Notes:

1. Repetitive rating: Pulse width is limited by maximum junction temperature.

2. L = 24mH, starting T

= 25°C.

J

=25°C unless otherwise specified.

A

±20

STOP

V

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Thermal Impedance

TA=25°C unless otherwise specified.

Symbol Parameter Value Unit

8DIP

θJA

θJC

Notes:

3. Free standing with no heatsink; without copper clad. Measurement condition – Just before junction temperature T

enters into OTP.

J

4. Measured on the DRAIN pin close to plastic interface.

5. All items are tested with the JEDEC standards: JESD 51-2 and 51-10 (DIP).

Junction-to-Ambient Thermal Impedance

Junction-to-Case Thermal Impedance

(3)

(4)

89 °C/W

14 °C/W

Fairchild FSQ211 service manual

Specifications and Main Features

Frequently Asked Questions

User Manual