Dostal's Designs: Limit Current with Integrated MOSFET (Download)

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Currents often have to be limited in electronic circuits. For example, in a USB port, excessive current flow must be prevented so that the electrical circuit can be reliably protected. Likewise, in a power bank, it’s critical that battery discharge be prevented. Discharging with too high of a current can lead to an impermissibly high voltage drop in the battery and an insufficient supply voltage to the downstream device.

Thus, it is often necessary to limit a current flow to a specific value. Most power converters have overcurrent limiters to protect themselves from damage due to excess currents. In some dc-dc converters, the threshold can even be adjusted.