Patent ID: 6992473

Claim:
A current-sensing circuit for DC/DC buck converters comprising: a power supply voltage; a pass device, wherein its source is connected to said power supply voltage, its drain is connected to the inductor of said buck converter and its gate is connected to the gate of an source follower and to the output of a gate driver; a first means of resistance, which is connected between said power supply voltage and the source of a source follower whose gate is connected to the gate of said pass device; a first source follower, wherein its source is connected to said means of resistance, its gate is connected to the gate of said pass device, and its drain is connected to the inductor of said buck converter; a gate driver wherein the output is connected to the gate of said pass device and to the gate of the said first source-follower; a second means of resistance, which is connected between the source of said first source follower and the source of a second source follower; a second source follower, wherein its source is connected to said second means of resistance, its gate is connected to the gate of a third source follower, and its drain is connected to a current source; a current source, generating a current tracking a voltage reference; a reference voltage; a third source follower, wherein its gate is connected to the gate of said second source follower and to the drain of said second source follower, its drain is connected to a third means of resistance and to an output voltage, and its source is connected to a fourth means of resistance; a third means of resistance, being connected between the drain of said third source follower and ground; a fourth means of resistance, being connected between the source of said third source follower and said power supply voltage; and an output voltage tracking the amount of current being provided to the inductor of a DC/DC buck converter.