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OPA548: Maximum Continuous Current limit for Dual Power Supply

Prodigy 70 points

Replies: 2

Views: 41

Part Number: OPA548

I am making a power supply with the OPA548T.  I am trying to get +4A of current continuously on the output.  My voltage rails are +10V and -5V. My power supply will not go negative. My voltage output will be from 0V to +5V. My current limit will be adjustable from 0.1A to 4A. Will the OPA548 work?  I have tried using the OPA549 that doesn't have the current limit adjustment range that I need.

Thanks for the help.

  • For your -5V and +10V supplies, and 0V to 5V output voltage, OPA548 should work fine for as long as you do not violate the input common-mode and/or output voltage ranges as shown below.  However, OPA548 is specified ONLY up to +/-3A dc output current so it may not work at 4A - see below.

    I'm not sure what you mean by the lack of current adjustment in OPA549 - it is specified from 0 to +/-10A (see below).  If you meant to say the current limit tolerance is above 200mA, this may be calibrated out. But considering that you need 4A dc output current, you should use OPA549 instead of OPA548.

    Marek Lis, MGTS
    Sr Application Engineer
    Precision Analog - TI Tucson

  • In reply to Marek Lis:

    Thanks for the information