Patent ID: 7524107
Filing Date: 2009-04-28
Classification: G01K

Abstract:
1. A thermostat circuit that is provided as an integrated circuit, comprising: a temperature sensor circuit that is arranged to sense an operating temperature associated with the thermostat circuit to provide a sense signal to a first node; a trip-point reference circuit that is factory adjusted to provide a temperature compensated reference signal to a second node; a switching circuit that includes a first input that is coupled to the first node, a second input that is coupled to the second node, a control input that is coupled to a fifth node, and an output that is coupled to a third node, wherein the switching circuit is arranged to selectively couple one of the first node and the second node to the third node in response to a control signal that is received at the fifth node; wherein the fifth node is configured to receive the control signal from a source external to the thermostat circuit; an amplifier circuit that includes an input coupled to the third node and an output coupled to a fourth node, wherein the fourth node corresponds to an analog output terminal; a comparator circuit that includes a first input that is coupled to the first node, a second input that is coupled to the second node, and an output that is coupled to a sixth node, wherein the sixth node corresponds to a comparator output terminal; and a logic circuit that generates an output voltage in response to the output of the comparator circuit and the external control signal.