MC33260P Ver la hoja de datos (PDF) - ON Semiconductor
Número de pieza
componentes Descripción
Fabricante
MC33260P
ON Semiconductor
MC33260P Datasheet PDF : 22 Pages
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MC33260
D1...D4
Rstup
r
+
15 V
Cpin8
VCC
1
8
2
7
3
6
4
5
Figure 38. Circuit Supply Voltage
+
PDIP−8 CONFIGURATION SHOWN
MC33260 VCC SUPPLY VOLTAGE
In some applications, the arrangement shown in Figure 38
must be implemented to supply the circuit. A startup resistor
is connected between the rectified voltage (or one−half
wave) to charge the MC33260 VCC up to its startup
threshold (11 V typically). The MC33260 turns on and the
VCC capacitor (Cpin8) starts to be charged by the PFC
transformer auxiliary winding. A resistor, r (in the range of
22 W) and a 15 V Zener should be added to protect the circuit
from excessive voltages.
When the PFC preconverter is loaded by an SMPS, the
MC33260 should preferably be supplied by the SMPS itself.
In this configuration, the SMPS starts first and the PFC gets
active when the MC33260 VCC supplied by the power
supply, exceeds the device startup level. With this
configuration, the PFC preconverter doesn’t require any
auxiliary winding and finally a simple coil can be used.
PCB LAYOUT
The connections of the oscillator and Vcontrol capacitors
should be as short as possible.
Preconverter Output
VCC
1
8
+
2
7
3
6
+
4
5
+
+
+
+
+
SMPS Driver
DIP−8 CONFIGURATION SHOWN
Figure 39. Preconverter Loaded by a Flyback SMPS: MC33260 VCC Supply
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