DI-33 View Datasheet(PDF) - Power Integrations, Inc
Part Name
Description
MFG CO.
'DI-33' PDF : 2 Pages View PDF
1
2
Design Idea DI-33
®
TinySwitch®-II Wide Range DVD
Supply: <50 mW No-load Consumption
Application Device
Power Output Input Voltage
Output Voltage
Topology
DVD Player TNY268P 11 W cont. 17 W pk. 85-265 VAC +3.3 V, +5.0 V, +12.0 V, -12 V Flyback
Design Highlights
• No-load input power <50 mW
• 700 mW of output power with 1 W input
• Built-in frequency jitter allows low cost π filter
• 132 kHz operation minimizes transformer size and turns,
providing good cross-regulation
• High efficiency – >77% minimum
• Meets CISPR22B/EN55022B and FCC B with >10 dB margin
Key Design Points
• An optional low voltage bias circuit, D9 and C10, powers U1
via R6, reducing light and zero load power consumption.
This provides bias current that would otherwise be provided
from the DRAIN by the internal high voltage current source.
The current source is disabled when the BP pin is fed
externally, an internal clamp limiting the voltage to
6.3 V. The bias supply is designed to produce 7.5 V at
no-load. Resistor R6 is chosen to provide
approximately 500 µA into the BP pin, the maximum
consumption at no-load.
• Good cross-regulation on 5 V and 3.3 V outputs is
achieved by minimizing secondary leakage through
C8
1 nF
Y1
D1 & D2
1N4007
F1
L
85-265
VAC
N
C3
0.047 µF
X2
D3 & D4
1N4007
R7
100 Ω
VR1
P6KE180
C2
0.01 µF
1 kV
1
C1 & C4
33 µF
400 V
R5
47 Ω
R1
2 MΩ
(Optional)
4
D5
1N4007
TinySwitch-II
D
EN
BP
L1
U1 S
1.4 mH TNY268
0.5 A
C5
0.1 µF
50 V
the use of foil windings and dual sense feedback via R15
and R16.
• To minimize potential noise coupling to the SOURCE pin
during common mode surges, the Y1 capacitor C8 is
connected between secondary return and the HV DC rail.
• Resistors R5 and R7 damp ringing to improve EMI.
• Optional soft-finish capacitor C7 eliminates output startup
overshoot.
• Optional under-voltage resistor R1 provides clean startup
and prevents output glitches on power down.
R1 = (VUV-2.5 V)/50 µA.
• Small loop areas in the secondary layout around D10,
C12, D9, C11, D7, C15, D8 and C9 together with post-
filters L2/C20, L3/C17 and L4/C18 provide low output
ripple, below 50 mV p-p.
8
D7
UF4003 C15
D9
1N5822
470 µF
25 V
13
D10
1N5822
C11
1800 µF
25 V
L2
3.3 uH
C20
150 µF
25 V
L3
3.3 uH
C17
470 µF
10 V
12 V, 0.4 A
5 V, 1.6 A
3.3 V, 0.7 A
9
L4
3.3 uH
C12
1000 µF
10 V
C18
470 µF
10 V
RTN
11
D8 UF4003
C9
220 µF
25 V
C6
220 µF
25 V
-12 V, 0.1 A
14
R6 R12
D6 1N4148 3.3 kΩ 1 Ω
6
1/2 W
C10
10 µF
50 V
R8
1 kΩ
5,7
U2
PC817
C7
10 µF
50 V
R9
200 Ω
R16
6.34 kΩ
U2
1%
R10
3.3 kΩ
C14
0.1 µF
R15
20 kΩ
1%
U3
TL431
R13
10 kΩ
1%
Figure 1. TinySwitch-II DVD Player Schematic.
PI-3205-091302
DI-33
www.powerint.com
September 2002
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