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Unread 06-02-2015, 17:22
rich2202 rich2202 is offline
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Re: Problems with the Voltage Regulation Module VRM

Quote:
Originally Posted by juchong View Post
a calibrated Keithley power supply set at 12.3V/1.5A as my source
I think you need more than 1.5A as your source. One output port alone on the VRM is rated for 12V/2A peak, and 12V/1.5A continuous.

Part of your power-up problem may be not having enough input current.

Given the minimum wiring size of 24 AWG, they are expecting peak draw of 3.5 amps.

Assuming maximum continuous power draw on all ports, that would be 0.5 and 1.5 amps at 12 volts, and 0.5 amps and 1.5 amps at 5 volts. That means a minimum draw of 2.83 amps at 12 volts continuous, and peak draw minimum of 3.55 amps at 12 volts. Assuming 80% efficiency, that would be 3.5 amps input to deliver the maximum rated continuous power draw.