US 5,347,224 AGranted

Current monitoring circuit having controlled sensitivity to temperature and supply voltage

AssigneeAnalog Devices, Inc.

InventorA. Paul Brokaw

Life of this patent

Estimating the term…

Loading patent…

Abstract

An integrated circuit including a comparator having two output states and being responsive to a voltage developed across a shunt in the circuit so that the comparator assumes one of its two output states when the voltage developed across the shunt is greater than a threshold switching voltage and the other of its two output states when the voltage developed across the shunt is less than the threshold switching voltage. The integrated circuit additionally includes a threshold switching voltage sensitivity control circuit, coupled to and controlling the comparator, for controlling a sensitivity of the threshold switching voltage to changes in a supply voltage of the lamp circuit and for controlling a sensitivity of the threshold switching voltage to changes in temperature of the integrated circuit.

Claims17

Dependent claims

An apparatus for monitoring current flowing through a shunt in a circuit, comprising:

a comparator having two output states and being responsive to a voltage developed across a shunt in the circuit as a result of the current flowing through the circuit, the shunt being coupled to the comparator, so that the comparator assumes one of its two output states when the voltage developed across the shunt is greater than a predetermined threshold switching voltage of the comparator and the other of its two output states when the voltage developed across the shunt is less than said threshold switching voltage, said threshold switching voltage changing as a result of changes in a supply voltage of the circuit or changes in temperature;
and
a threshold switching voltage sensitivity control circuit coupled to and controlling the threshold switching voltage of the comparator for providing selectable control of sensitivity of the threshold switching voltage to changes in a supply voltage of the circuit and for providing selectable control of a sensitivity of the threshold switching voltage to changes in temperature.

Dependencies are inferred from the claim text.