Design Idea DI-39
®
TOPSwitch-GX
13 W, Universal
Input DVD Supply with 70 mW No-load
Application
DVD
Device
TOP244P
Power Output
13 W (17 W pk)
Input Voltage
85-265 VAC
Output Voltage
3.3 V / 5 V / 12 V / -12 V
Topology
Flyback
®
Design Highlights
•
•
•
•
•
•
•
High efficiency multi-ouptut flyback (77% minimum)
Topology scalable to higher powers
Excellent cross-regulation
Excellent input no-load consumption <70 mW input
132 kHz switching frequency allows smaller transformer
Frequency jitter eliminates common-mode EMI choke
>10 dB margin against CISPR22-B conducted EMI with
artificial hand grounding
The supply operates at full frequency at high and medium
power and reduces frequency at light loads. Components D9
and C10 rectify and filter the bias voltage.
TOPSwitch-GX
frequency jitter allows conducted EMI
compliance without a common-mode choke, using only
capacitors C1, C4 and inductor L1 as an EMI filter.
Components D5 and C2 form a capacitor clamp circuit
absorbing leakage inductance energy during normal operation.
Zener VR1 clamps the voltage to a safe level during abnormal
and transient conditions. After clamping, reverse current
flows through D5, recovering some of the energy. Resistor
R5 limits the reverse current and, with R7, improves EMI by
limiting the ringing on the drain. Continuous mode operation
allows reduced primary and secondary peak currents,
optimizing cross regulation and load regulation by
minimizing leakage inductance induced voltage shifts.
Resistors R15 and R16 share the feedback from the 3.3 V
and 5 V outputs for good cross-regulation.
L2
3.3
µH
Operation
The
TOPSwitch-GX
uses current mode feedback to achieve
excellent no-load standby. Components C16, R1 and Q2 provide
a constant current powering the
TOPSwitch-GX
CONTROL
pin. Resistor R2 feeds the remainder of Q2 current to the M pin,
reducing
TOPSwitch-GX
current limit with increased current.
Resistor R11 sets the maximum current limit of the device.
Components R6, Q1 and C13 implement slope compensation.
C8
1 nF
Y1
D1-D4
1N4005
F1
3.15 A
250 VAC
85 - 265
VAC
C3
0.047
µF
x2
C1
33
µF
400V
VR1
P6KE180
C4
33
µF
400V
R7
100
Ω
C2
0.01
µF
1 KV
R5
47
Ω
D5
1N4007
D7
UF4003
12 V, 400 mA
C20
150
µF
25 V
C15
470
µF
25 V
L3
3.3
µH
L4
3.3
µH
R9
200
Ω
U2B
PC817
R8
1 kΩ
R16
6.34 kΩ
C17
470
µF
10 V
5 V, 1.6 A
C11
D11
1800
µF
1N5822
25 V
D10
1N5822
D8
UF4003
C12
1000
µF
10 V
C9
220
µF
25 V
C6
220
µF
25 V
R12
1 1/2 W
PC817
U2A
3.3 V, 700 mA
C18
470
µF
10 V
RTN
R15
20 kΩ
C14
0.1
µF
R1
270
Ω
TOPSwitch-GX
U1
TOP244P
R2
20 kΩ
D
M
CONTROL
C
R10
3.3 kΩ
C16
0.33
µF
R6
20 kΩ
C7
10
µF
50 V
U3
TL431CLP
R13
10 kΩ
Q2
2N3906
Q1
2N3906
- 12 V, 100 mA
D9
C10 1N4148
47
µF
50 V
R11
7.5 kΩ
L1
1.4
µH
0.5 A
S
C13
47 pF
R14
6.8
Ω
C5
47
µF
10 V
C19
0.1
µF
PI-3321-111902
Figure 1. TOPSwitch-GX DVD Player Schematic.
.
DI-39
www.powerint.com
November 2002
DI-39
Key Design Points
• Use of foil for the 3.3 V and 5 V windings also helps to
optimize cross-regulation.
• Optional capacitor C7 is the “soft-finish” capacitor and
prevents overshoot on startup.
• Compact layout for components D7, D10, D11, C11,
C12, C15 will improve cross-regulation and efficiency.
Compact layout for L2, L3, L4, C17, C18, and C20 will
achieve best output ripple.
• Figure 2 shows conducted EMI at 230 VAC full load, with
output “Artificial Hand” grounding. Floating output return
gives lower results.
• Table 2 shows the cross regulation of the supply over load
for both 115 VAC and 230 VAC.
PI-3408-112502
TRANSFORMER PARAMETERS
Core Material
Bobbin
EEL25
Himag MZ4 EEL25.4, Taiwan AL of
344 nH/T2
EEL25 Vertical 14 Pins
Shield: 32T x 2 x 32 AWG
Primary: 64T x 2 x 32 AWG
Bias: 10T x 4 x 32 AWG
Shield: 2T x 8 x 32 AWG
+3.3V: 4T x foil 0.052 x 14 mm
+5V: 1T x foil 0.052 x 14 mm
+12V: 4T x 4 x 32 AWG
-12V: 7T x 4 x 32 AWG
Shield (NC-5), tape, Primary (1-4), tape,
Bias (7-6), tape, Shield (5-NC), tape,
+12 V (13-8), +3.3 V (11,12-9,10), +5 V
(9-10,13), tape, -12 V (14-11, 12), tape
1.42 mH
±10%
at 132 kHz
Winding Details
Winding Order
(Pin Numbers)
Primary Inductance
(Pins 1-4 all others
open)
Primary Resonant
Frequency
Leakage Inductance
80
70
60
50
40
QP
AV
Quasi Peak
300 kHz minimum
30
µH
maximum
dBµV
30
20
10
0
-10
-20
0.15
1.0
10.0
-100.0
Average
Table 1. Transformer Construction Information.
MHz
Output
Voltage
(V)
3.3
5
12
-12
Load
Range
(%)
10-100
10-100
10-100
100
Cross Regulation (%)
-4
-3
-2
-1
0
1
2
3
4
Figure 2. EMI at 230 VAC Full Load with "Artificial Hand"
Grounding of Output.
Table 2. Worst Case Cross Regulation at 115 VAC and 230 VAC.
For the latest updates, visit our Web site:
www.powerint.com
Power Integrations reserves the right to make changes to its products at any time to improve reliability or manufacturability.
Power Integrations does not assume any liability arising from the use of any device or circuit described herein, nor does it convey any
license under its patent rights or the rights of others. The products and applications illustrated herein (including circuits external to the
products and transformer construction) may be covered by one or more U.S. and foreign patents or potentially by pending U.S. and foreign
patent applications assigned to Power Integrations. A complete list of Power Integrations’ patents may be found at www.powerint.com.
The PI Logo,
TOPSwitch
,
TinySwitch
,
LinkSwitch
and
EcoSmart
are registered trademarks of Power Integrations, Inc.
PI Expert
is a trademark of Power Integrations, Inc. ©Copyright 2002, Power Integrations, Inc.
WORLD HEADQUARTERS
AMERICAS
Power Integrations, Inc.
San Jose, CA 95138 USA
Customer Service:
Phone:
+1 408-414-9665
Fax:
+1 408-414-9765
e-mail: usasales@powerint.com
CHINA
Power Integrations International
Holdings, Inc.
China
Phone:
+86-755-8367-5143
Fax:
+86-755-8377-9610
e-mail: chinasales@powerint.com
A
11/02
EUROPE & AFRICA
Power Integrations (Europe) Ltd.
United Kingdom
Phone:
+44-1344-462-300
Fax:
+44-1344-311-732
e-mail: eurosales@powerint.com
KOREA
Power Integrations
International Holdings, Inc.
Seoul, Korea
Phone:
+82-2-782-2840
Fax:
+82-2-782-4427
e-mail: koreasales@powerint.com
SINGAPORE
Power Integrations, Singapore
Republic of Singapore 308900
Phone:
+65-6358-2160
Fax:
+65-6358-2015
e-mail: singaporesales@powerint.com
JAPAN
Power Integrations, K.K.
Keihin-Tatemono 1st Bldg.
Japan
Phone:
+81-45-471-1021
Fax:
+81-45-471-3717
e-mail: japansales@powerint.com
APPLICATIONS HOTLINE
World Wide +1-408-414-9660
TAIWAN
Power Integrations
International Holdings, Inc.
Taipei, Taiwan
Phone:
+886-2-2727-1221
Fax:
+886-2-2727-1223
e-mail: taiwansales@powerint.com
INDIA (Technical Support)
Innovatech
Bangalore, India
Phone:
+91-80-226-6023
Fax:
+91-80-228-9727
e-mail: indiasales@powerint.com
APPLICATIONS FAX
World Wide +1-408-414-9760
www.powerint.com
京公网安备 11010802033920号
EEWORLD
