Digital temperature compensated crystal oscillator

摘要

Data such as temperature compensation data for a temperature compensated crystal oscillator is stored in a converted form in a memory section to reduce a required memory capacity. A digital input signal such as a 10 bit digital signal representing an ambient temperature of the crystal oscillator is divided into a first signal section (such as upper 6 bits) and a second signal section (the remaining lower four bits, for example). The first signal section is inputted to the memory section as an address input, and a data item specified by the address input is read out from the memory section. The readout data item and the second signal section are supplied, as decoder input signal, to a decoder for performing a mathematical operation by using these decoder input signals. In the case of the temperature compensated crystal oscillator system, the result of the mathematical operation of the decoder is supplied to a digital-to-analog converter.