A 1.2 V BiCMOS companding current-mode integrator for /spl Sigma//spl Delta/-modulators

A companding current-mode integrator is proposed for very low voltage /spl Sigma//spl Delta/-converters. Neither the input nor the output current of this integrator is limited by the biasing current as it operates in class AB. This property allows the design of integrators with low biasing current levels and therefore low average power consumption, which are still able to process large signals. The proposed integrator operates at 1.2 V and has a power consumption of 21 /spl mu/W. It is used as a building block for a first order /spl Sigma//spl Delta/-converter for voice-band applications.

[1]  Christian C. Enz,et al.  Low-voltage companding current-mode integrators , 1995, Proceedings of ISCAS'95 - International Symposium on Circuits and Systems.

[2]  Yannis Tsividis,et al.  On linear integrators and differentiators using instantaneous companding , 1995 .

[3]  E. Seevinck,et al.  Companding current-mode integrator: A new circuit principle for continuous-time monolithic filters , 1990 .

[4]  G. van Ruymbeke,et al.  Design of low-power and low-voltage log-domain filters , 1996, 1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96.