Abstract: A function generator circuit includes a temperature detecting circuit outputting a detection voltage corresponding to an ambient temperature and having a linear temperature characteristic. Zeroth-order, first-order and second-order component generating circuits generate a zeroth-order component, a first-order component and a second-order component, respectively, of the control signal. A third-order component generating circuit generates a third-order component of the control signal based on the detection voltage. An adder-subtractor generates the control signal by obtaining a sum of the zeroth-order component, the first-order component, and the third-order component and adding or subtracting the second-order component to or from the sum. The second-order component generating circuit corrects a temperature at an inflection point of the control signal.

Abstract: A function generator circuit for outputting a control signal to an oscillating circuit includes a temperature detecting circuit for outputting a detection voltage corresponding to an ambient temperature and having a linear temperature characteristic, a zeroth-order component generating circuit for generating a zeroth-order component of the control signal, a first-order component generating circuit for generating a first-order component of the control signal, a second-order component generating circuit for generating a second-order component of the control signal, a third-order component generating circuit for generating a third-order component of the control signal based on the detection voltage, and an adder-subtractor that generates the control signal by obtaining a sum of the zeroth-order component, the first-order component, and the third-order component and adding or subtracting the second-order component to or from the sum.