ST LCD-PDP/TV Schematic

Power Supply Solutions

for small/medium/big size

LCD-PDP/TV

Content

¾ Classical Approach:

¾ 60W SMPS (<20”)
¾ 200W SMPS (up to 30-32”)

¾ Resonant Approach:

¾ 70W SMPS (<20”)
¾ 180W SMPS (up to 30”)
¾ 500W SMPS (up to 50”

LCD-TV, 42” PDP-TV

60W LCD-TV Power Supply:

Block Diagram

•Operation close to
the boundary
between CCM and
DCM: variable
operating frequency

•Zero Voltage/Zero
Current Switching at
turn-on achievable

•Less EMI generated

•Variable frequency
spreads spectrum

Power Supply Unit

EMI filter&

Vac

Bridge

Rectifier

Advanced

PWM

Controller

+12V

•Stand-By function
put into optional

Feedback

60W LCD-TV Power Supply:

Specifications

Wide Input Voltage Range: 90-265VAC
Single Output Voltage (Vout):

Vout

5A12V

Total Output Power: 60W

RemarksCurrent

Accurate OCP and OVP circuit are
building in the simple can be optional.

60W LCD-TV Power Supply: Schematic

L6565

60W LCD-TV Power Supply:

Testing Report

Loading efficiency

Test Loading

12VOuput
5AFull Load (FL)

0.0416A (0.5W)Stand By
0ANo Load

Testing Results

Input PowerFL Eff.Input Voltage

No LoadStand By

81.7%90V

83.2%100V

87.0%240V

87.4%264V

A 60W LCD-TV Power Supply

L6565: Quasi-Resonant SMPS

• Current Mode Quasi-Resonant PWM

controller

• Micropower Start-up Current (40µA
typ.)

• Low Quiescent Current (3mA typ.)

• ZCD input for QR operation/external
synchronization

• Frequency Foldback function

• Line Voltage Feedforward function

• Pulse-by-pulse overcurrent

controller

protection

• 2nd overcurrent level with Hiccup­mode operation

• Disable function

• Internal RC filter on Current Sense

• Package: Minidip and SO8

QR Conversion:
Quasi-Resonant Concept

z Llk &Cd

Vin

Cin

Lp

Lm

Llk

Ls

Cd

VDS

Vout

¾ Operation close to the boundary between CCM

and DCM: variable operating frequency

¾ Zero Voltage/Zero Current Switching at turn-

on achievable

¾ Less EMI generated
¾ Variable frequency spreads spectrum

z VDS

z Vin

z Ip

z IPKs

z IPKp

z VR

z Pri z Sec

z TON

z T = 1/ fsw

z TFW

z Tv

z Lp &Cd

z VDS @ Vin2 >Vin

z NO ZVS!

z Vin2

z ZVS

z t

z Is @ Vin2 >Vin

z Ip @ Vin2 >Vin

¾ZVS condition: Vin ≤ VR

200W LCD-TV Power Supply:

Block Diagram

•PFC
200W critical control
mode with ZCD
function for a cost­effective application

•Main Converter
200W Flyback
Converter for middle
size LCD-PDP/TV
application

•Standby
10W Flyback
converter with build­in mosfet PWM
controller and circuit

Power Supply Unit

EMC filter

Vac

&Bridge
Rectifier

PFC+PWM+Aux

L6562+L5991

+L6590

Feedback

+24V

+12V

DC DC

conv.

+5V

standby

+5V

to switch off

200W LCD-TV Power Supply:

Specifications

Wide Input voltage range: 90-265VAC
Multi Output Voltages (Vout):

Vout

24V
12V

5V

5Vsb

6A
3A
2A
2A

Total output Power : 200W

RemarksCurrent

5V output use DC-DC converter which
can be put in optional.

200W LCD-TV Power Supply: Schematic

Advanced PWM Controller

L6562+L5991+L6590

L5973D