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
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