TOP258MN Power Integrations, TOP258MN Datasheet - Page 24

• Manufacturer Part Number: TOP258MN
• Description: IC OFFLINE SWIT PROG OVP 10CSDIP
• Manufacturer: Power Integrations
• Series: TOPSwitch®-HXr
• Type: Off Line Switcherr

Specifications of TOP258MN

• Output Isolation: Isolated
• Frequency Range: 119 ~ 145kHz
• Voltage - Output: 700V
• Power (watts): 140W
• Operating Temperature: -40°C ~ 150°C
• Package / Case: 10-SDIP (0.300", 7.62mm), 9 Leads
• Output Voltage: 700 V
• Input / Supply Voltage (max): 9 V
• Input / Supply Voltage (min): - 0.3 V
• Duty Cycle (max): 78 %
• Switching Frequency: 132 KHz
• Operating Temperature Range: - 40 C to + 150 C
• Mounting Style: SMD/SMT
• Maximum Operating Temperature: + 150 C
• Minimum Operating Temperature: - 40 C
• Output Current: 6.88 A
• Output Power: 48 W
• For Use With: 596-1193 - KIT REF DESIGN TOP HX FOR TOP258
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 596-1191-5

A High Effi ciency, 65 W, Universal Input Power Supply
The circuit shown in Figure 44 delivers 65 W (19 V @ 3.42 A) at
88% effi ciency using a TOP260EN operating over an input
voltage range of 90 VAC to 265 VAC.
Capacitors C1 and C6 and inductors L1 and L2 provide
common mode and differential mode EMI fi ltering. Capacitor C2
is the bulk fi lter capacitor that ensures low ripple DC input to the
fl yback converter stage. Capacitor C4 provides decoupling for
switching currents reducing differential mode EMI.
In this example, the TOP260EN is used at reduced current limit
to improve effi ciency.
Resistors R5, R6 and R7 provide power limiting, maintaining
relatively constant overload power with input voltage. Line
sensing is implemented by connecting a 4 MΩ impedance from
the V pin to the DC rail. Resistors R3 and R4 together form the
4 MΩ line sense resistor. If the DC input rail rises above
450 VDC, then TOPSwitch-HX will stop switching until the
voltage returns to normal, preventing device damage.
This circuit features a high effi ciency clamp network consisting
of diode D1, zener VR1, capacitor C5 together with resistors R8
and R9. The snubber clamp is used to dissipate the energy of
the leakage reactance of the transformer. At light load levels,
very little power is dissipated by VR1 improving effi ciency as
compared to a conventional RCD clamp network.
Figure 44.
Rev. F 01/09
L
E
N
90 - 265
24
VAC
4 A
F1
12 mH
L1
2.2 M
65 W, 19 V Power Supply Using TOP260EN.
R1
275 VAC
TOP252-262
330 nF
C1
2.2 M
Ferrite Bead
R2
3KBP08M
L2
BR1
250 VAC
470 pF
C3
120 F
400 V
C2
2.0 M
2.0 M
15 k
R3
R4
1%
R7
5.1 M
6.8 M
100 nF
400 V
R5
R6
C4
2.2 nF
1 kV
D
S
C5
100
DL4937
R8
CONTROL
BZY97C180
D1
X
V
TOPSwitch-HX
180 V
VR1
BAV19WS
TOP260EN
BAV19WS
F
100 nF
1 k
50 V
D5
R9
C8
U1
D3
C
4
5
6
250 VAC
RM10 FL1
2.2 nF
The secondary output from the transformer is rectifi ed by diode
D2 and fi ltered by capacitors C13 and C14. Ferrite Bead L3 and
capacitors C15 form a second stage fi lter and effectively reduce
the switching noise to the output.
Output voltage is controlled using a LM431 reference IC.
Resistor R19 and R20 form a potential divider to sense the
output voltage. Resistor R16 limits the optocoupler LED current
and sets the overall control loop DC gain. Control loop
compensation is achieved using C18 and R21. The components
connected to the control pin on the primary side C8, C9 and
R15 set the low frequency pole and zero to further shape the
control loop response. Capacitor C17 provides a soft fi nish
during startup. Optocoupler U2 is used for isolation of the
feedback signal.
Diode D4 and capacitor C10 form the bias winding rectifi er and
fi lter. Should the feedback loop break due to a defective
component, a rising bias winding voltage will cause the zener
VR2 to break down and trigger the over voltage protection
which will inhibit switching.
An optional secondary side over voltage protection feature
which offers higher precision (as compared to sensing via the
bias winding) is implemented using VR3, R18 and U3. Excess
voltage at the output will cause current to fl ow through the
optocoupler U3 LED which in turn will inject current in the V-pin
through resistor R13, thereby triggering the over voltage
protection feature.
T1
C6
100 nF
D4 BAV19WS
25 V
5.1
FL2
C7
6.8
R13
100
R15
47 F
3
2
16 V
R14
C9
5.1 k
R12
22 F
50 V
C10
1 F
50 V
C16
100 V
1 nF
C12
MBR20100CT
73.2 k
LTY817C
R10
PC357A
U3B
U2B
D2
33
R16
1N5248B
18 V
VR2
2 M
R11
33 F
35 V
C17
470 F
25 V
C13
LTY817C
U2A
1N4148
100 nF
50 V
C11
D6
470 F
680
LM431
R16
25 V
C14
U4
2%
100 nF
C18
Ferrite
Bead
L3
1 k
68.1 k
R21
47 F
25 V
C15
10 k
R19
R20
www.powerint.com
PI-4998-021408
BZX79-C22
VR3
22 V
PC357A
47
R18
U3A
19 V, 3.42 A
RTN