Abstract

In this thesis, a new technique for temperature compensation of G m -C filters is presented. An Operational Transconductance Amplifier (OTA) as well as the output buffers is implemented in STMicroelectronics 9O-nm technology with 1.2 V supply voltage. Variation of a gate-capacitance implemented by an NMOS transistor with respect to temperature is investigated. Using negative feedback the G m -cells' transconductance is locked to the reciprocal of a resistance array. Temperature behaviour of the G m -C filter is examined by the behaviour of a G m -C integrator without receiving an external frequency reference. Temperature dependency of the G m /C ratio, which determines the unity-gain frequency of the integrator. is minimized by arranging the temperature dependency of the resistors. Unique properties of a proposed resistive bridge allow for the synthesis of temperature coefficients beyond the range of coefficients of constituent elements. With a set of practical elements a variation of only 0.66% in G m /C has been achieved over -40°C to 120°C.