Www.fairchildsemi.com Fairchild Power Switch(FPS) TV Solution Power Conversion.

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Fairchild Power Switch(FPS)

TV Solution

Power Conversion

2

Features and Advantages of FSCQ-series

Features• Optimized for Quasi-resonant converter (Low EMI and High Efficiency)• Fully avalanche rated and 100% tested SenseFET• Pulse-by-pulse current limiting• Improved reliability through various protection functions

Over voltage, Over load, Over current, Thermal shutdown

• Advanced Burst operation for low power consumption in standby (<1W)• Internal Soft start function (20ms)• Extended Quasi-resonant operation for wide operation range• Reduced startup and operating currents

Advantages• Reduced board space (simple & compact circuit design)• Decreased assembly time and field failure rate Enhanced productivity

3

FSCQ-series Functional Block Diagram

9V/15V

3 1

2

4

AuxiliaryVref Main bias

S

Q

Q

R

OSC

Vcc

Vref

Idelay

IFB

VSD

TSD

Vovp

Sync

Vocp

S

Q

Q

R

R

2.5R

Vcc good

Vcc Drain

FB

GND

AOCP

Gatedriver

Vcc good

LEB600ns

PWM

Soft start

Internalbias

Normaloperation

VBurst

Vref

Ib

Vref

Ibufb

Burst modeController

Normal operation Burst Switching

5Sync

Threshold

Quasi-resonant(QR) switching

controller

+

-

+

-

S

Q

Q

R

Power Reset

4.6V/2.6V : Normal QR3.0V/1.8V : Extended QR

fs

QRC Control

Burst Mode Operation

TSD

OLP

OVP

AOCP

Latch Mode

Current Mode Control

Auto Restart Mode

SenseFET

4

FPS lineup for CRT-TV application

Device

Function Protection Option

PKGVdmax

(V)

Ipeak

(A)

Po(max)(1)

85-265VAC

Fopr

(KHz)

Rds(on)

Max ()OLP OCL OVP TSD

High Power Quasi-Resonant Converter Applications

Color TV

KA5Q0565RT 650 3.5 60 QRC 2.2 YES YES YES YES TO-220F-5L

KA5Q0740RT 400 5.0 85 QRC 1.1 YES YES YES YES TO-220F-5L

KA5Q0765RTH 650 5.0 85 QRC 1.6 YES YES YES YES TO-220F-5L

KA5Q12656RTH 650 6.0 140 QRC 0.9 YES YES YES YES TO-220F-5L

KA5Q1265RFH 650 8.0 160 QRC 0.9 YES YES YES YES TO-3PF-5L

KA5Q1565RF 650 11.5 210 QRC 0.65 YES YES YES YES TO-3PF-5L

FSCQ0565RT 650 3.5 60 QRC 2.2 YES YES YES YES TO-220F-5L






FSCQ1565RP 650 11.5 210 QRC 0.65 YES YES YES YES TO-3PF-7L

5

KA5Q series V.S FSCQ-series

Generation KA5Q-Series FSCQ-Series FSCQ Advantages

Control MethodQRC/PSR

High Efficiency/Low EMI

QRC with high frequency limit

High Efficiency/Low EMI

Temp. of device can be lower at high line input

Start-up current

/Operation current

Max. 200uA

/ 18mA(always constant)

Max. 50uA

/ 6mA(reduced in burst mode)

Lower standby power

Output regulation in standby

By Vcc control By Feedback control Just difference of method

Output voltage drop in standby

About half Any levelLower standby power but

MCU reset must be considered

Standby power Under 2W Under 1W

Soft start None 20mSReducing stress on Power

MOSFET & transformer

SenseFET Q-FET S-FET

PKG TO220F-5L/TO3PF-5L TO220F-5L/TO3PF-7LSame PCB pattern can be

used for different PKG

6

Power Consumptions in standby mode

7

Typical Application circuit

C10310uF50V

1

3

4

10

T1EER3540

12V, 1A

C2041000uF

35V

D205EGP20D

11

LF101

C101330nF

275VAC

FUSE250V3.0A

C102220uF400V

RT1015D-9

BD101

D1011N4937

R1035.1Ω

0.25W

6

7

R1041.5kΩ0.25W2 4

5

1

3

GND

DrainSYNC

FB

Vcc

D1031N4148

IC101FSCQ0765RT

C10647nF50V

R105470Ω0.25W

C1053.9nF50V

ZD10118V1W

C1071nF1kV

BEAD101

D1021N4937

C210470pF

1kV

18V, 0.5A

D204EGP20D

C2051000uF

35V

13

C209470pF

1kV12

125V, 0.4A

D202EGP20J

C201100uF160V

14

C207470pF

1kV

L201BEAD

16

C20247uF160V

24V, 0.5A

D203EGP20D

C2031000uF

35V

17

C208470pF

1kV18

OPTO101817A

R2011kΩ

0.25W

C20622nF50V

C3012.2nF

Q201KA431

R20339kΩ0.25W

R2021kΩ

0.25W

R205220kΩ0.25W

R2044.7kΩ0.25W

VR20130kΩ

D201Q202

KSC945 R2065.1kΩ0.25W

R2075.1kΩ0.25W

SW 201

15

R102120kΩ0.25W

R101120kΩ0.25W

R1061kΩ1W

C10410uF50V

ZD2025.1V0.5W

R2081kΩ

0.25W

Normal

Standby

D104UF4007

8

Normal Quasi-Resonant Switching

Advantages- Reduced switching noise (Low EMI)

- Improved efficiency

- Removed RCD snubber

9

Normal Quasi-Resonant Switching

Limitations- Intermittent switching at light load due to a relatively large LEB time- Increased switching loss at light load

Vds

Ids

Vds

Ids

Output power

Switching frequency

Light load

Heavy load

10

Extended Quasi-Resonant Switching

Advantages- Guarantee stable operation over wide load range

- Improve efficiency at light load condition

Output power

Switchingfrequency

Normal QR Switching

Extended QR Switching

90kHz

45kHz

11

Internal Soft-start

• Internal soft start (20ms)• For a fast output build up, offset is introduced in the soft start

85V input 265V input

12

Over load Protection - Output short


13

Abnormal over current protection – Diode short


14

Over voltage protection -Feedback open


15

Burst operation - basic features

Vo2

Vfb

Iop

Vds

0.4V

Vo2_min

4mA

PictureOn

PictureOff

PictureOn

Burst Mode

250uA

- Drop output voltage to below half (any level) to minimize the loss caused by leakage current in the high voltage output

- Reduce the effective switching frequency to minimize switching loss

- Reduce the FPS operating current in the burst operation

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Burst operation - Output drop circuit

Picture ON

MicomLinearRegulator

VO2

VO1 (B+)

KA431R2

R1

R3

Rbias

RD

RFCF D1Q1

A

CR

Dz

- Normal mode : Vo1 (B+) is regulated

- Standby mode : Vo2 is regulated

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Burst operation waveforms

Normal Standby Standby Normal

18

Burst operation waveforms

Vi=85Vac Vi=265Vac

1. Vds

2. Vcc

3. Vfb

4. Id

Www.fairchildsemi.com Fairchild Power Switch(FPS) TV Solution Power Conversion.

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