Fairchild FSQ0370RLA, FSQ0370RNA, FSQ0370RLA, FSQ0370RNA Schematic

FSQ0370RNA, FSQ0370RLA Green Mode Fairchild Power Switch (FPS™)

FSQ0370RNA / FSQ0370RLA — Green Mode Fairchild Power Switch (FPS™)

March 2012

Features

 Internal Avalanche Rugged 700V SenseFET  Consumes Only 0.8W at 230V

Burst-Mode Operation

& 0.5W Load with

AC

 Precision Fixed Operating Frequency: 100kHz  Internal Startup Circuit and Built-in Soft-Start  Pulse-by-Pulse Current Limiting, Auto-Restart Mode  Over-Voltage Protection (OVP), Overload

Protection (OLP), Internal Thermal Shutdown Function (TSD)

 Under-Voltage Lockout (UVLO)  Low Operating Current: 3mA  Adjustable Peak Current Limit

Applications

 Auxiliary Power Supply for PC and Server  SMPS for VCR, SVR, STB, DVD, and DVCD Player  Printer, Facsimile, and Scanner  Adapter for Camcorder

Description

The FSQ0370 consists of an integrated Current Mode Pulse Width Modulator (PWM) and an avalanche rugged 700V SenseFET. It is specifically designed for highperformance offline Switched Mode Power Supplies (SMPS) with minimal external components. The integrated PWM controller features include: a fixedfrequency generating oscillator, Under-Voltage Lockout (UVLO) protection, Leading-Edge Blanking (LEB), an optimized gate turn-on / turn-off driver, Thermal Shutdown (TSD) protection, and temperaturecompensated precision current sources for loop compensation and fault protection circuitry.

Compared to a discrete MOSFET and controller or RCC switching converter solution, the FSQ0370 reduces total component count, design size, and weight while increasing efficiency, productivity, and system reliability. These devices provide a basic platform that is well suited for the design of cost-effective flyback converters, such as in PC auxiliary power supplies.

Related Application Notes

AN-4134 — Design Guidelines for Off-line Forward



Converters Using Fairchild Power Switch (FPS™)

 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

Ordering Information

Part Number Package Marking Code BV

FSQ0370RNA 8-Lead, Dual Inline Package (DIP)

FSQ0370RLA 8-Lead, LSOP

Q0370RA 700V 100KHz

f

DSS

R

OSC

DS(ON)(MAX)

4.75Ω

Application Circuit

AC

IN

FSQ0370RNA / FSQ0370RLA — Green Mode Fairchild Power Switch (FPS™)

DC

OUT

Vstr

Ipk

Vfb Vcc

Drain

PWM

Source

Figure 1. Typical Flyback Application

Table 1. Output Power Table

Product

FSQ0370RNA

FSQ0370RLA

(1)

(2)

Adapter

230V

(3)

±15%

AC

Open Frame

85-265VAC

(4)

Adapter

(3)

Open Frame

(4)

20W 27W 13W 19W

Notes:

1. The maximum output power can be limited by junction temperature.

2. 230V

or 100/115VAC with doubler.

AC

3. Typical continuous power in a non-ventilated enclosed adapter with sufficient drain pattern as a heat sink at 50°C ambient.

4. Maximum practical continuous power in an open-frame design with sufficient drain pattern as a heat sink at 50°C ambient.

Internal Block Diagram

Figure 2. Functional Block Diagram

Pin Assignments

Figure 3. Pin Configuration (Top View)

Pin Definitions

Pin# Name Description

1 GND SenseFET source terminal on the primary side and internal control ground.

Positive supply voltage input. Although connected to an auxiliary transformer winding,

2 Vcc

3 Vfb

4 Ipk

5 Vstr

6, 7, 8 Drain

current is supplied from pin 5 (Vstr) via an internal switch during startup (see Figure 2).

It is not until V opens and device power is supplied via the auxiliary transformer winding.

The feedback voltage pin is the non-inverting input to the PWM comparator. It has a

0.9mA current source connected internally, while a capacitor and optocoupler are typically connected externally. A feedback voltage of 6V triggers overload protection (OLP). There is a delay while charging external capacitor C current source. This delay prevents false triggering under transient conditions, but allows the protection mechanism to operate in true overload conditions.

This pin adjusts the peak current limit of the SenseFET. The 0.9mA feedback current source is diverted to the parallel combination of an internal 2.8kΩ resistor and any external resistor to GND on this pin. This determines the peak current limit. If this pin is tied to Vcc or left floating, the typical peak current limit is 1.1A.

This pin is connected to the rectified AC line voltage source. At startup, the internal switch supplies internal bias and charges an external storage capacitor placed between the Vcc pin and ground. Once V

The drain pins are designed to connect directly to the primary lead of the transformer and are capable of switching a maximum of 700V. Minimizing the length of the trace connecting these pins to the transformer decreases leakage inductance.

reaches the UVLO upper threshold (12V) that the internal startup switch

CC

from 3V to 6V using an internal 5µA

fb

reaches 12V, the internal switch is opened.

CC

FSQ0370RNA / FSQ0370RLA — 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 Min. Max. Unit

V

Drain Pin Voltage 700 V

DRAIN

V

Vstr Pin Voltage 700 V

STR

IDM Drain Current Pulsed

EAS Single Pulsed Avalanche Energy

V

Supply Voltage 20 V

CC

V

Feedback Voltage Range -0.3 V

FB

P

Total Power Dissipation 1.5 W

D

T

Recommended Operating Junction Temperature -40 Internally Limited

J

Operating Ambient Temperature

Storage Temperature

T

TA

STG

Notes:

5. Non-repetitive rating: pulse-width limited by maximum junction temperature.

6. L=51mH, starting T

=25°C.

J

(5)

12 A

(6)

230 mJ

=25°C, unless otherwise specified.

A

-40 +85

-55 +150

V

CC

°C

Thermal Impedance

Symbol Parameter Value Unit

θJA Junction-to-Ambient Thermal Resistance

θJC Junction-to-Case Thermal Resistance

ΨJT

Junction-to-Top Thermal Resistance

Notes:

7. Free-standing with no heat-sink, without copper clad.

8. Measured on the drain pin, close to the plastic interface.

9. Measured on the package top surface.

(7)

80

(8)

20

(9)

35

°C/W

Electrical Characteristics

T A=25°C unless otherwise specified.

Symbol Parameter Condition Min. Typ. Max. Unit

SenseFET Section

I

Zero-Gate-Voltage Drain Current

DSS

R

DS(ON)

C

Input Capacitance VGS=0V, VDS=25V, f=1MHz 315 pF

ISS

C

Output Capacitance VGS=0V, VDS=25V, f=1MHz 47 pF

OSS

C

Reverse Transfer Capacitance VGS=0V, VDS=25V, f=1MHz 9 pF

RSS

t

Turn-On Delay VDD=350V, ID=1A 11.2 ns

d(on)

tr Rise Time VDD=350V, ID=1A 34 ns

t

Turn-Off Delay VDD=350V, ID=1A 28.2 ns

d(off)

tf Fall Time VDD=350V, ID=1A 32 ns

Control Section

f

Switching Frequency 92 100 108 kHZ

OSC

Δf

OSC

D

Maximum Duty Cycle Measured at 0.1 x VDS 55 60 650 %

MAX

D

Minimum Duty Cycle 0 0 0 %

MIN

V

START

V

7 8 9

STOP

IFB Feedback Source Current VFB=GND 0.7 0.9 1.1 mA

t

Internal Soft-Start Time

S/S

Burst-Mode Section

V

BURH

V

0.3 0.4 0.5 V

BURL

V

100 200 300 mV

BUR(HYS)

Protection Section

I

Peak Current Limit di/dt=240mA/µs 0.97 1.10 1.23 A

LIM

t

Current Limit Delay

CLD

TSD Thermal Shutdown Temperature

VSD Shutdown Feedback Voltage 5.5 6.0 6.5 V

V

Over-Voltage Protection 18 19 V

OVP

I

Shutdown Delay Current VFB=4V 3.5 5.0 6.5 µA

DELAY

t

Leading-Edge Blanking Time

LEB

Total Device Section

IOP

ICH Startup Charging Current VCC=0V 0.70 0.85 1.00 mA

V

STR

Notes:

10. Pulse test: Pulse width ≤ 300μs, duty ≤ 2%.

11. These parameters, although guaranteed, are not 100% tested in production.

(10)

=700V, VGS=0V 50

V

DS

VDS=560V, VGS=0V,

=125°C

T

C

Drain-Source On-State Resistance

(10)

Switching Frequency Variation

VGS=10V, ID=0.5A 4.00 4.75 Ω

(11)

-25°C < TJ < 85°C

UVLO Threshold Voltage VFB=GND

(11)

V

=4V

FB

200

±5 ±10 %

11 12 13

10 ms

µA

V

0.5 0.6 07 V

Burst-Mode Voltage T

(11)

500 ns

(11)

200 ns

Operating Supply Current (Control Part Only)

Supply Voltage VCC=0V 24 V

STR

=25°C

J

125 140 °C

VCC=14V 1 3 5 mA

FSQ0370RNA / FSQ0370RLA — Green Mode Fairchild Power Switch (FPS™)

Typical Performance Characteristics

Characteristic graphs are normalized at TA=25°C.

FSQ0370RNA / FSQ0370RLA — Green Mode Fairchild Power Switch (FPS™)

Figure 4. Operating Frequency (f

Figure 6. Maximum Duty Cycle (D

) vs. TA Figure 5. Over-Voltage Protection (V

OSC

) vs. TA Figure 7. Operating Supply Current (IOP) vs. TA

MAX

OVP

) vs. TA

Figure 8. Start Threshold Voltage (V

) vs. TA Figure 9. Stop Threshold Voltage(V

START

STOP

) vs. TA

Fairchild FSQ0370RLA, FSQ0370RNA, FSQ0370RLA, FSQ0370RNA Schematic [ru]

Specifications and Main Features

Frequently Asked Questions

User Manual