Patent ID: 7576575

Claim:
A reset signal generator comprising: an output unit for generating a reset signal from a pre-reset signal, wherein the reset signal follows a supply voltage signal before transitioning to a predetermined level when the supply voltage signal reaches a tripping voltage; a trip signal generator for generating a trip signal from the supply voltage signal; an inverter unit for generating the pre-reset signal from the trip signal and the supply voltage signal; and a variation reducing unit coupled to the inverter unit and configured to shift the tripping voltage by a variable amount for different temperatures such that a range of the tripping voltage is reduced with temperature variation, wherein the inverter unit includes a first field effect transistor, and wherein the variation reducing unit includes a second field effect transistor, and wherein the first and second field effect transistors are connected in series between a voltage supply generating the supply voltage signal and an input to the output unit, and wherein the first and second field effect transistors have respective channels of opposite conductivity type, and wherein a gate to source path of the second field effect transistor is connected directly in series with a drain to source path of the first field effect transistor between the voltage supply and the input to the output unit without an intervening device between the gate to source path of the second field effect transistor and the drain to source path of the first field effect transistor; and wherein respective drain to source paths of no more than two field effect transistors of the inverter unit and no more than one field effect transistor of the variation reducing unit are connected in series between the voltage supply and a ground node such that the respective drain to source paths of a total of no more than three field effect transistor are connected in series between the voltage supply and the ground node.