| 摘要 |
PURPOSE:To correct frequencies in a wide range and correct slippage of frequencies dependent upon temperature change also by detecting an ambient temperature through a selection circuit using a gate, a CR oscillator, etc., and by co-operating output data and a frequency divider circuit. CONSTITUTION:Pulse generation circuit OSC receives the influence of an ambient temperature to change the output frequency, and memory circuits M1...M7 store previously respective data corresponding to frequencies of difference between respective output frequencies in temperatures and a target frequency. Under an uncorrection state, control circuit C1 which generates the output from circuit OSC is provided, and the output frequency of circuit C1 is lowered through frequency divider circuits D2 and D3. Then, a selection circuit consisting of gates G1 and G2, CR oscillator A using a thermistor, etc., detects an ambient temperature, and by co-operations of selected data and outputs of circuits D1 and D2, control circuit C2 corrects the output frequency of circuit C1. |
