Patent ID: 6998907

Claim:
A circuit for receiving high common mode voltage signals with low-voltage devices, the circuit comprising: a first transconductance stage that includes an output, a differential input, and a source, wherein the first transconductance stage is arranged to provide a first current at the output of the first transconductance stage in response to a differential input signal that is received at the differential input, and wherein the first transconductance stage is arranged to provide, at the source of the first transconductance stage, a first common mode signal that is associated with an input common mode voltage of the differential input signal; a load circuit that is arranged to provide a first voltage from the first current; and a first cascode transistor that includes a first cascode base, a first cascode emitter, and a first cascode collector, wherein the first cascode emitter is coupled to the output of the first transconductance stage, the first cascode base is arranged to receive a cascode base signal such that a voltage at the output of the first transconductance stage substantially tracks the input common mode voltage to prevent a breakdown condition from occurring if a closed loop operation is being employed; the cascode base signal is based, in part, on the first common mode signal; and wherein an output voltage is based, at least in part, on a voltage that is associated with the first cascode collector.