Method, Circuit, and Apparatus to Increase Robustness to Inrush Current in Power Switch Devices

A method comprising:

• receiving an enable signal with a first circuit;
• after the enable signal is asserted, injecting a first current into a first input terminal of the first circuit;
• after injecting the first current into the first input terminal, comparing a first voltage at the first input terminal with a first threshold;
• when the first voltage is higher than the first threshold, generating a first voltage ramp at an output of the first circuit;
• and
• when the first voltage is lower than the first threshold, generating a second voltage ramp at the output of the first circuit, the second voltage ramp being slower than the first voltage ramp.

An electronic fuse (e-fuse) comprising:

• an input terminal;
• an output terminal;
• a power transistor coupled between the input terminal and the output terminal;
• an amplifier having an output coupled to a control terminal of the power transistor and having a first input coupled to the power transistor;
• and
• a ramp generator circuit having an output coupled to the amplifier, wherein the ramp generator circuit is configured to:
• receive an enable signal,
• after the enable signal is asserted, injecting a first current into a first input of the ramp generator circuit;
• after injecting the first current into the first input of the ramp generator circuit, compare a first voltage at the first input of the ramp generator circuit with a first threshold;
• when the first voltage is higher than the first threshold, generate a first voltage ramp at the output of the ramp generator circuit;
• and
• when the first voltage is lower than the first threshold, generate a second voltage ramp at the output of the ramp generator circuit, the second voltage ramp being slower than the first voltage ramp.