鈥?/div>
Fold - back characteristics provides overload protection for external components
Burst operation under secondary short - circuit condition implemented
Protection against open or short of the control loop
Switch - off if line voltage is too low (undervoltage switch - off)
Line voltage depending compensation of fold - back point
Soft start for quiet start - up without noise generated by the transformer
Chip - over temperature protection (thermal shutdown)
On - chip ringing suppression circuit against parasitic oscillations of the transformer
P-DIP-8-1
鈥?/div>
In the different voltage ranges the switched - mode Power supply (SMPS) behaves as
follow:
No load operation.
The Power supply is operating in the burst mode at typical 20 to 40
kHz. The output voltage can be a little bit higher or lower than the nominal value
depending on the design of the transformer and the resistors of the control voltage divider.
Nominal operation.
The switching frequency is reduced with increasing load and
decreasing AC voltage. The duty factor primarily depends on the AC voltage. The output
voltage is only depends on the load.
Overload point.
Maximum output Power is available at this point of the output
characteristic.
Overload.
The energy transferred per operation cycle is limited at the top. Therefore the
output voltages declines by secondary overloading.
PIN DEFINITION
Pin #
1.
2.
3.
4.
5.
6.
7.
8.
Function
Information Input Concerning Secondary Voltage
Information Input Regarding the Primary Current
Input for Primary Voltage Monitoring
Ground
Output
Supply Voltage Input
Input for Soft Start and Integrator Circuit
Input for the Feedback of the Oscillator
1
1
2
3
4
