Tuning and Compensation of Temperature Effects in Analog Integrated Filters

In this paper several tuning strategies for integrated active filters are discussed. Furthermore we compare two compensation schemes to decrease the temperature dependence of the transconductance value of a differential gain stage. The compensation circuitry consists of on-chip temperature sensors and a level adjustment circuit all realized by standard CMOS transistor techniques. The temperature sensors requires small chip area and consumes a small amounts of power. The performance of the temperature compensation schemes has been evaluated in a first-order transconductance-C filter application where the temperature dependence of the bandwidth and thereby the transconductance value are measured. Simulations show that the filters relative bandwidth variation due to temperature changes can be as low as 0.07% in the temperature interval of .