Patent ID: 7710188

Claim:
An analog front end circuit comprising: an input terminal; a voltage input path including: a first voltage buffer circuit in communication with said input terminal, and a first switch coupled to an output of said first voltage buffer circuit; a current input path including: a second voltage buffer circuit in communication with said input terminal, a current to voltage conversion circuit in communication with said input terminal and said second voltage buffer circuit, and a second switch coupled to an output of said second voltage buffer circuit; a control circuit, coupled to said first and second switches, to alternately select the voltage input path or the current input path; a temperature compensation circuit in communication with said first and second switches, wherein said temperature compensation circuit comprises an IPTAT-IPP circuit; a sampling circuit alternately coupled to said first and second switches; a PMOS source follower coupled to an output of said sampling circuit; and a level shifter coupled between said PMOS source follower and said temperature compensation circuit.