Patent ID: 8400849

Claim:
An electronic device comprising: a first supply voltage domain; a second supply voltage domain; a low drop output voltage regulator (LDO) coupled to receive a supply voltage of the first supply voltage domain and to provide a supply voltage of the second supply voltage domain; the LDO being configured to be switched into a first state for providing and maintaining the supply voltage of the second supply voltage domain and into a second state for providing a high impedance output to the second supply voltage domain; a comparator coupled to monitor the first supply voltage level at a first supply voltage node and to switch the LDO from the first state to the second state, the comparator comprising a differential input transistor stage having one input coupled to the first supply voltage node and another input coupled to receive a first reference voltage level, a first current source configured to supply a current of a first magnitude, a second current source configured to supply a current of a second magnitude, and a capacitor, wherein the first magnitude is greater than the second magnitude and the first current source is coupled with one side to the differential input stage for supplying the differential input stage and with the other side to a first node, the second current source is coupled with one side to the first node and with the other side to a second supply voltage node having a second supply voltage level and the capacitor is coupled with one side to the first node and with the other side to the first supply voltage node, and wherein the differential stage comprises a third input being coupled to receive a second reference voltage that is derived from the supply voltage level at the first supply voltage node.