Abstract: A digital temperature control system based on single chip processor, ADC and PID control algorithm was developed for a miniaturized digital rubidium atomic frequency standard (MRAFS) with low power consumption. The basic theory underlying the PID control algorithm and the strategies for tuning the operational parameters were discussed. The experimental results showed that the digital system developed had low power consumption and smaller volume relative to the traditional analog temperature control system, and similar accuracy of temperature control. The digital temperature control system developed could meet the operational requirement of MRAFS.

Key words: rubidium atomic frequency standard, digital temperature control, PID control algorithm, precision