Title :
A 2.7-V elliptical MOSFET-only gmC-OTA filter
Author :
Lindfors, Saska ; Halonen, Kari ; Ismail, Mohammed
Author_Institution :
Electron. Circuit Design Lab., Helsinki Univ. of Technol., Espoo, Finland
fDate :
2/1/2000 12:00:00 AM
Abstract :
The gmC-operational transconductance amplifier (OTA) technique relaxes transconductor output swing and dc-gain requirements, which makes it a suitable candidate for low-voltage circuits. To reduce the power consumption of OTA´s, an excess phase shift compensation with an automatic tuning circuit is used. A floating triode-region transconductor with a novel biasing to compensate the effect of channel-length modulation is presented. The two independent common-mode levels in a gmC-OTA integrator are utilized to bias a pMOS as a linear capacitor. This enables the realization of the floating-transmission zero capacitors with a pure digital CMOS process. The implementation and the experimental results for a third order 2.7-V all-MOS elliptical filter with 64-dB dynamic range and 0.1% linearity are presented
Keywords :
MOSFET circuits; continuous time filters; elliptic filters; low-power electronics; operational amplifiers; 2.7 V; automatic tuning circuit; continuous time filter; digital CMOS process; elliptical MOSFET gmC-OTA filter; excess phase shift compensation; floating triode-region transconductor; floating-transmission zero capacitor; integrator; low-voltage circuit; operational transconductance amplifier; pMOS linear capacitor; Bipolar transistors; Dynamic range; Filters; Linearity; MOSFET circuits; Power supplies; Thermal degradation; Threshold voltage; Transconductance; Transconductors;
Journal_Title :
Circuits and Systems II: Analog and Digital Signal Processing, IEEE Transactions on
