MICROCOMPUTER CONTROL TYPE PIEZO-ELECTRIC OSCILLATOR

摘要

PURPOSE: To suppress the fluctuation of the output duty ratio due to the change of an operation point of a transistor when the surrounding temperature of the piezo-electric oscillator is changed. ;CONSTITUTION: The device consists of a piezo-electric oscillator 1, integrator 2 inputting the output and converting the duty ratio into the analog voltage, A/D converter 3 digitally coding the analog output, microcomputer circuit 4 inputting the output digital code of the A/D converter 3, memory circuit 5, and A/D converters 6 and 7 converting the output from the microcomputer 4 into the analog voltage and supplying it to the piezo-electric oscillator. When the surrounding temperature of the piezo-electric oscillator is changed, the operation point of transistors 8 and 9 is changed and the output duty ratio is changed. The change of the duty ratio is detected and the analog voltage applied to the base bias of respective transistors 8 and 9 according to it is calculated by the microcomputer 4. By applying it, the duty ratio can be kept constant.;COPYRIGHT: (C)1995,JPO