1

I was wondering if integrated eFuse solutions exist that are designed to protect a low voltage AC bus. In my application I would like to replace a 2A PTC that protects a 24VAC bus but I cannot find an IC which explicitly states that it supports AC current.
For example, the TPS2660 has a diagram in the datasheet that suggests bidirectionality with its two FETs, but also states that it is designed to protect from reverse current flow, which would prevent use with AC.
Does a solution like this exist or am I bound to design a discrete circuit, given that I have strict thermal and space constraints?
Thanks in advance for the help.

Giorgio
  • 96
  • 5
  • The two MOSFETs are not there to support current to flow in both directions. Note how the MOSFETs have a diode in parallel, all MOSFETs have this (it is the bulk-source diode). If only one MOSFET was used, current can still flow through that diode. So **two** MOSFETs are needed in anti-series. I expect that designing an "AC fuse circuit" will not be trivial. Can you explain **why** the PTC solution needs to be replaced and what you want to protect against. – Bimpelrekkie Oct 06 '20 at 13:35
  • Perhaps just use a polyfuse? They're similar to PTC thermistors but with a much sharper cutoff, just what you want in a fuse. – Hearth Oct 06 '20 at 13:41
  • The minimum input voltage is 4.2V on that part. You not only want it to work below 4.2V, but you want it to work at negative voltages, so 'no'. – Spehro Pefhany Oct 06 '20 at 15:50

1 Answers1

2

No,

as of now, there is no direct solution, you can make it using Triac.

But if your appliance can run on DC, you can use a full bridge rectifier and some capacitors to make it DC.

Deepak
  • 896
  • 2
  • 8