TOP243 View Datasheet(PDF) - Power Integrations, Inc
Part Name
Description
Manufacturer
TOP243 Datasheet PDF : 52 Pages
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TOP242-250
A High Efficiency, Enclosed, 70 W, Universal Adapter Supply damage. Capacitor C11 has been added in parallel with VR1 to
The circuit shown in figure 42 takes advantage of several of the reduce Zener clamp dissipation. With a switching frequency of
TOPSwitch-GX features to reduce cost, power supply size and 132 kHz a PQ26/20 core can be used to provide 70 W. To
increase efficiency. This design delivers 70 W at 19 V, from an maximize efficiency, by reducing winding losses, two output
85 to 265 VAC input, at an ambient of 40 °C, in a small sealed windings are used each with their own dual 100 V Schottky
adapter case (4” x 2.15” x 1”). Full load efficiency is 85% at 85 rectifier (D2 and D3). The frequency reduction feature of the
VAC rising to 90% at 230 VAC input.
TOPSwitch-GX eliminates any dummy loading to maintain
regulation at no-load and reduces the no-load consumption of the
Due to the thermal environment of a sealed adapter a TOP249Y power supply to only 520 mW at 230 VAC input. Frequency
is used to minimize device dissipation. Resistors R9 and R10 jittering provides conducted EMI meeting the CISPR 22
externally program the current limit level to just above the (FCC B) / EN55022B specification, using simple filter compo-
operating peak DRAIN current at full load and low line. This nents (C7, L2, L3 and C6) even with the output earth grounded.
allows the use of a smaller transformer core size without
saturation during startup or output load transients. Resistors R9 To regulate the output an optocoupler (U2) is used with a
and R10 also reduce the current limit with increasing line secondary reference sensing the output voltage via a resistor
voltage, limiting the maximum overload power at high input divider (U3, R4, R5, R6). Diode D4 and C15 filter and smooth
General Information & Table of Contents line voltage, removing the need for any protection circuitry on the output of the bias winding. Capacitor C15 (1µF) prevents the
the secondary. Resistor R11 implements an under voltage and bias voltage from falling during zero to full load transients.
over voltage sense as well as providing line feed forward for
reduced output line frequency ripple. With resistor R11 set at
2 MΩ the power supply does not start operating until the DC rail
Resistor R8 provides filtering of leakage inductance spikes
keeping thePbirasovdoltuagecctonSstanet leveencattohigrh Goutpuutildoaeds. 1
Resistor R7, C9 and C10 together with C5 and R3 provide loop
voltage reaches 100 VDC. On removal of the AC input the UV
sense prevents the output glitching as C1 discharges,
compensation.
Data Sheets 2
turning off the TOPSwitch-GX when the output regulation is lost Due to the large primary currents, all the small signal control
or when the input voltage falls to below 40 V, whichever
occurs first. This same value of R11 sets the OV threshold to
components are connected to a separate source node that is Kelvin
Application Notes 3 connected to the source pin of the TOPSwitch-GX. For improved
450 V. If exceeded, for example during a line surge, common mode surge immunity the bias winding common re-
TOPSwitch-GX stops switching for the duration of the surge
extending the high voltage withstand to 700 V without device
turns directly to the DC bulk capacitor (C1).
Design Ideas 4
C13 C12 C11
0.33 µF 0.022 µF 0.01 µF
400 V 400 V 400 V
BR1
RS805
8 A 600 V
Design Tools C7 2.2 nF
D2
MBR20100
PERFORMANCE SUMMARY
Output Power:
70 W
5
Y1 Safety
Regulation:
± 4%
Efficiency:
≥ 84%
VR1
P6KE-
200
D1
D3
Quality and Reliability 6 Ripple:
< 120 mV pk-pk
No Load Consumption: < 0.52 W @ 230 VAC
MBR20100
C3
C14
Package Information 7 820 µF
25 V
L1
200 µH
0.1 µF
50 V
19 V
@ 3.6 A
UF4006
L2
820 µH
2A
C1
150 µF
C6
400 V
0.1 µF
X2
L3
RT1
75 µH
10 Ω t° 2 A
1.7 A
F1
J1 3.15 A
L
N
R11
DPA-Switch DC-DC Seminar 8 D4
1N4148
C2
820 µF
25 V
R1
270 Ω
C4
820 µF
25 V
RTN
LinkSwitch & TinySwitch-II AC-DC Seminar 2 MΩ
1/2 W
R8
T1
4.7 Ω
C15
TOPSwitch-GX 1 µF
U2
PC817A
R2
1 kΩ
R4
31.6 kΩ
1%
R13
562 Ω
9
TOPSwitch-GX AC-DC Seminar 10 D
L
TOP249Y
R9
CONTROL
C
U1
50 V
C9
1%
4.7 nF 50 V
13 MΩ
C10
Sales Representatives and Distributors 11 S
R10
20.5 kΩ
XF
C8
0.1 µF
50 V
R3
6.8 Ω
C5
U3
TL431
R7
56 kΩ
0.1 µF
50 V
R6
4.75 kΩ
47 µF
1%
16 V
PI-2691-033001
Figure 42. 70 W Power Supply using Current Limit Reduction with Line and Line Sensing for UV and OV.
22 H
9/02
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