I'm using Max4080 to measure the current:

enter image description here


simulate this circuit – Schematic created using CircuitLab

The problem is it can't detect short circuit because when RS- is connected to ground, Rsense will be at low-side. Max4080 is a high-side current measurement chip...

  • Is there anyway at all to make this chip to detect short circuit(with extra circuitry)?

  • Can I use this chip to measure the current and then detect the short circuit with something like this?

I know measuring current at low-side is easy and I'll eventually going to use it if I can't find a solution(easy/cheap/accessible) to measure the current at high-side.


From the linked datasheet, the output is valid when the common mode of RS+/- is 4.5-76 V. You will be able to measure current accurately until your 15 V / 1 A supply is forced below 4.5 V output by its overcurrent protection. What are you trying to use short circuit detection for? If you want to protect the power supply, you will need additional circuitry. If you want to know the power supply status and its self-protection is adequate for your application, can you get that as a feature of the supply?

  • \$\begingroup\$ I need the short circuit protection because I'm building a lab PSU. \$\endgroup\$ Dec 1 '19 at 7:18
  • \$\begingroup\$ Then you probably should design the 15 V power supply to have protection features and will also need a different current sense amplifier if you want to adjust your output below 4.5 V nominal. \$\endgroup\$ Dec 1 '19 at 17:45

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