US 9,793,808 B1 · Enhanced bidirectional current sensing and replication

Abstract

A current replication circuit includes a bias circuit and a first transistor sized, relative to a second transistor to be sensed, according to a first scaling factor, the first transistor having an on-resistance associated therewith. The current replication circuit further includes at least one transconductance amplifier having first and second signal paths. The first signal path is connected with the bias circuit in a closed loop configuration such that a quiescent bias point of the transconductance amplifier is controlled as a function of the on-resistance of the first transistor. The second signal path is connected with the second transistor in an open loop configuration and is adapted to convert a sensed input voltage to a corresponding current output signal as a function of the quiescent bias point of the transconductance amplifier, the current output signal being proportional to a current flowing through the second transistor.

Claims17

Dependent claims

A current replication circuit, comprising:

a first transistor sized, relative to a second transistor to be sensed, according to a first scaling factor, the first transistor having an on-resistance associated therewith;
a bias circuit;
at least a first transconductance amplifier having first and second signal paths, the first signal path being connected with the bias circuit in a closed loop configuration such that a quiescent bias point of the first transconductance amplifier is controlled as a function of the on-resistance of the first transistor, the second signal path being connected with the second transistor in an open loop configuration and being adapted to convert a sensed input voltage to a corresponding current output signal as a function of the quiescent bias point of the first transconductance amplifier, the current output signal being proportional to a current flowing through the second transistor.

A current sensing and replication circuit, comprising:

a first transistor sized, relative to a second transistor to be sensed, according to a first scaling factor, the first transistor having an on-resistance equal to an on-resistance of the second transistor multiplied by the first scaling factor, the first transistor receiving a prescribed reference current and generating a first voltage as a function of the reference current and the on-resistance of the first transistor;
at least a first transconductance amplifier coupled with the first transistor, a transconductance of the first transconductance amplifier being set in a closed-loop arrangement as a function of the on-resistance of the first transistor, the first transconductance amplifier generating an output sense signal in an open-loop arrangement as a function of the transconductance of the first transconductance amplifier and a second voltage at a sensed circuit node connected with the second transistor, the output sense signal being indicative of a current flowing through the second transistor.

Dependencies are inferred from the claim text.

Enhanced bidirectional current sensing and replication

Life of this patent

Enhanced bidirectional current sensing and replication

Life of this patent

Abstract

Claims17