TOP247FN Power Integrations, TOP247FN Datasheet - Page 22
![IC OFFLINE SWIT UVLO HV TO262](/photos/7/32/73240/596-to-262-7c_sml.jpg)
TOP247FN
Manufacturer Part Number
TOP247FN
Description
IC OFFLINE SWIT UVLO HV TO262
Manufacturer
Power Integrations
Series
TOPSwitch®-GXr
Type
Off Line Switcherr
Datasheet
1.TOP242GN-TL.pdf
(52 pages)
Specifications of TOP247FN
Output Isolation
Isolated
Frequency Range
66 ~ 132kHz
Voltage - Output
700V
Power (watts)
165W
Operating Temperature
-40°C ~ 150°C
Package / Case
TO-262-7 (Formed Leads), 5 Leads
Output Voltage
12 V
Input / Supply Voltage (max)
265 VAC
Input / Supply Voltage (min)
85 VAC
Duty Cycle (max)
83 %
Switching Frequency
132 KHz
Supply Current
2.2 mA
Operating Temperature Range
- 40 C to + 150 C
Mounting Style
Through Hole
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
Company:
Part Number:
TOP247FN
Manufacturer:
PowerInt
Quantity:
850
Company:
Part Number:
TOP247FN
Manufacturer:
POWER
Quantity:
15 000
Figure 43. 250 W, 48 V Power Supply using TOP249.
A High Efficiency, 250 W, 250-380 VDC Input Power Supply
The circuit shown in Figure 43 delivers 250 W (48 V @
5.2 A) at 84% efficiency using a TOP249 from a 250 VDC to
380 VDC input. DC input is shown, as typically at this power
level a p.f.c. boost stage would preceed this supply, providing the
DC input (C1 is included to provide local decoupling). Flyback
topology is still usable at this power level due to the high output
voltage, keeping the secondary peak currents low enough so
that the output diode and capacitors are reasonably sized.
In this example, the TOP249 is at the upper limit of its power
capability and the current limit is set to the internal maximum
by connecting the X pin to SOURCE. However, line sensing
is implemented by connecting a 2 MΩ resistor from the L pin
to the DC rail. If the DC input rail rises above 450 VDC, then
TOPSwitch-GX will stop switching until the voltage returns to
normal, preventing device damage.
Due to the high primary current, a low leakage inductance
transformer is essential. Therefore, a sandwich winding with
a copper foil secondary was used. Even with this technique,
the leakage inductance energy is beyond the power capability
of a simple Zener clamp. Therefore, R2, R3 and C6 are added
in parallel to VR1. These have been sized such that during
normal operation, very little power is dissipated by VR1,
the leakage energy instead being dissipated by R2 and R3.
22
+250-380
TOP242-250
VDC
0 V
O
11/05
PERFORMANCE SUMMARY
Output Power:
Line Regulation:
Load Regulation:
Efficiency:
Ripple:
No Load Consumption:
22 µF
400 V
C1
P6KE200
1/2 W
2 MΩ
VR1
R1
≤ 1.4 W (300 VDC)
250 W
± 1%
± 5%
≥ 85%
< 100 mV pk-pk
68 kΩ
2 W
R2
BYV26C
68 kΩ
2 W
R3
D1
D
S
4.7 nF
1 kV
CONTROL
CONTROL
C6
X
L
2.2 nF Y1
F
T1
TOPSwitch-GX
0.1 µF
50 V
C3
C
C7
TOP249Y
U1
However, VR1 is essential to limit the peak drain voltage
during start-up and/or overload conditions to below the 700 V
rating of the TOPSwitch-GX MOSFET.
The secondary is rectifed and smoothed by D2 and C9, C10 and
C11. Three capacitors are used to meet the secondary ripple
current requirement. Inductor L2 and C12 provide switching
noise filtering.
A simple Zener sensing chain regulates the output voltage.
The sum of the voltage drop of VR2, VR3 and VR4 plus the
LED drop of U2 gives the desired output voltage. Resistor R6
limits LED current and sets overall control loop DC gain.
Diode D4 and C14 provide secondary soft-finish, feeding
current into the CONTROL pin prior to output regulation and
thus ensuring that the output voltage reaches regulation at start-
up under low line, full load conditions. Resistor R9 provides a
discharge path for C14. Capacitor C13 and R8 provide control
loop compensation and are required due to the gain associated
with such a high output voltage.
Sufficient heat sinking is required to keep the TOPSwitch-GX
device below 110 °C when operating under full load, low line
and maximum ambient temperature. Airflow may also be
required if a large heatsink area is not acceptable.
D2
1N4148
47 µF
D2
MUR1640CT
6.8 Ω
10 V
C3
R4
560 µF
63 V
C9
50 V
1 µF
C4
560 µF
63 V
C10
All resistor 1/8 W 5% unless
otherwise stated.
BZX79B22
BZX79B12
BZX79B12
150 nF
VR2 22 V
VR3 12 V
VR4 12 V
63 V
LTV817A
C13
U2
100 Ω
560 µF
R6
63 V
C11
3 µH 8A
56 Ω
R8
L2
68 µF
63 V
C12
D4
1N4148
22 µF
63 V
C14
10 kΩ
R9
PI-2692-081204
48 V@
5.2 A
RTN