130809 PRODUCT MANUAL PCM-DC-AT512-P 9
System
The PCM-DC-AT512-P is a high efciency, non-isolated switch mode power supply with a wide input range of 10-50 VDC.
From one common DC input, it supplies +5V, -12V, and 12V. The overall efciency of the power supply varies between 80
and 92% depending on the individual converter loading and input level.
Theory of Operation
The PCM-DC-AT512-P employs a variety of synchronous and asynchronous, single and multiphase, buck and buck-boost
topology DC-DC converters. The guaranteed input voltage range is 10-50 VDC, however operation is possible above
and below this input limit. Inputs below 10V may result in startup instability issues on the -12V and 12V supplies. With a
converter silicon rating of 60 VDC or greater, operation up to the 60 VDC is possible with reduced output power or active
cooling.
Derating Formula
The main 5V output on the PCM-DC-AT512-P may have to be derated depending on the user’s input voltage and
maximum ambient operating temperature.
Use the following formula to derate the main 5V, 20A output current:
IOUT = (215 - VIN - TAMB )/ 8.
IOUT = The output current in Amps. ( IOUT < 20)
VIN = Input voltage in Volts.
TAMB = Ambient operating temperature in degrees Celsius. (-40°C < TAMB < 85°C)
See Appendix D for more derating chart information.
