IRISMPS3 International Rectifier, IRISMPS3 Datasheet - Page 8

• Manufacturer Part Number: IRISMPS3
• Description: International Rectifier Kansas Street El Segundo CA 90245 USA
• Manufacturer: International Rectifier

shorter as it takes very little time to get the energy required into the transformer. Again the circuit is operating in
PRC mode with an input power of 825mW which again meets the Energystar and Blue Angel requirements for
no load standby power.
change can be seen by the drop on CH4, as this occurs we see the quasi-resonant info on the FB pin (CH3)
disappear after a short time due to the drop in voltage at the bias winding. This is a result of a high feedback
current from the opto ISO1 as the output voltage tries to go higher to compensate for the drop in load current. At
this point we see the feedback level is high enough to stop the drain from switching as can be seen by the flat
part of the waveform on CH1. Eventually the circuit stabilizes and the circuit starts operating again in the PRC
mode with a reduced Vcc and no quasi-resonant info on the FB pin.
efficiency vs AC input voltage for a full load output. This shows the efficiency well above the 85% level for most
of the input range.
8
Fig 7) shows the same details as in fig 6), but at 230VAC input, in this case you can see the on time is even
Fig 8) shows the circuit changing from Quasi-resonant mode to PRC mode due to a load change. The load
Efficiency
In this section we will show the efficiency of the circuit under various conditions. Fig 9) shows a graph of the
Fig 10) shows the efficiency vs load current for various input voltages.
Fig 8)Drain (D) voltage of IRIS4013K (CH1)/Vcc Voltage (CH2)/ FB pin voltage (CH3)/Load Current (CH4)
at 120VAC in/no load output
IRISMPS3
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