| CPC G01R 31/31727 (2013.01) [G01R 31/31721 (2013.01); H03K 19/0033 (2013.01); H03K 19/017509 (2013.01)] | 13 Claims |

|
1. A latchup detector comprising:
a level shifter comprising:
a first level-shifter circuit having an input electrically coupled to an output of a voltage regulator, the output having a regulator output voltage, the first level-shifter circuit configured to lower the regulator output voltage to a first voltage; and
a second level-shifter circuit having an input electrically coupled to an input of a chip, the input of the chip having a target supply voltage, the second level-shifter circuit configured to lower the target supply voltage to a second voltage, the second voltage lower than the first voltage,
wherein a voltage supply rail is electrically coupled to the output of the voltage regulator and to the input of the chip; and
a comparator having a first input electrically coupled to an output of the first level-shifter circuit to receive the first voltage and a second input electrically coupled to an output of the second level-shifter circuit to receive the second voltage, the comparator configured to produce a first output voltage when a difference between the first and second voltages is greater than or equal to a predetermined voltage difference and a second output voltage when the difference between the first and second voltages is less than the predetermined voltage difference;
wherein the comparator has a variable-threshold such that the predetermined voltage difference is programmable.
|