Current Limit Solid State Power Switch with Latch

Rajkumar Sharma
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SKU: EL88345
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The project published here is a solid-state power switch with current limiting that prevents damage to host devices from faulty load conditions. This analog current limit switch has low on-resistance P-channel MOSFET and INA202 driver IC from Texas Instrument. The project operates from input voltage in the range of 5V to 24V and can handle currents up to 2A. The versatile project can be used in Smart Power applications. It is widely used to clamp the overload current and deliver a constant current.

The project provides a 2A current if the load current increases more than the set point (2amps) automatically isolates the switch. The over-current limit threshold is set to 2 Amps but it can be programmed using an external resistor R7 and PR1 and by changing the value of Shunt resistor R1, refer datasheet of INA202 for more information on current adjustment and current limit. The circuit also requires a 5V logic supply other than the load supply. The Trimmer potentiometer helps to set the threshold current. Setting the output is simple using a trimmer pot, turning the trimmer potentiometer counterclockwise and connecting the current meter between loads, tying the reset wire to VCC 5V switch on the logic supply and logic supply, and turning the pot till it latches the output. D1 is the power LED.