Title :
A low-sensitivity programmable BJT current-mode filtering technique
Author :
Mathiazhagan, C.
Author_Institution :
Dept. of Electr. Eng., Indian Inst. of Technol., Madras, India
fDate :
9/1/1999 12:00:00 AM
Abstract :
A low-sensitivity temperature-compensated programmable BJT current-mode low-voltage filtering technique is proposed. We introduce a new technique in which the DC gain and the location of the second pole of the integrator are controlled such that the Q-enhancement, due to the second pole, is cancelled by the effect of finite DC gain. The technique is suitable for integration and can work with low-value capacitors. By making the filter time constant exactly proportional to reC, good linear tunability is achieved over many decades. The programming current is varied as proportional to absolute temperature (PTAT) to stabilize the time constant reC
Keywords :
Q-factor; bipolar analogue integrated circuits; circuit stability; circuit tuning; compensation; continuous time filters; current-mode circuits; gain control; integrating circuits; network analysis; poles and zeros; programmable filters; sensitivity analysis; BJT current-mode filtering technique; DC gain control; Q-enhancement; active filters; filter time constant stabilisation; finite DC gain; integrator pole; linear tunability; low-sensitivity filtering technique; low-value capacitors; low-voltage filtering technique; programmable filtering technique; programming current; second pole location control; temperature compensation; Bipolar transistor circuits; Capacitors; Cutoff frequency; Filtering; Low pass filters; MOSFET circuits; Mirrors; Nonlinear filters; P-n junctions; Temperature sensors;
Journal_Title :
Circuits and Systems I: Fundamental Theory and Applications, IEEE Transactions on
