A New PVT Compensation Technique Based on Current Comparison for Low-Voltage, Near Sub-Threshold LNA

• Published in: IEEE transactions on circuits and systems. I, Regular papers Vol. 62; no. 12; pp. 2908 - 2919
• Main Authors: Vinaya, M. M., Paily, Roy, Mahanta, Anil
• Format: Journal Article
• Language: English
• Published: New York IEEE 01-12-2015; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Amplifiers; Circuits; Compensation; Constant current; constant g_{m}; Corners; Deviation; Devices; Electric potential; LNA; Logic gates; low power; Low voltage; MOS devices; Performance evaluation; PVT compensation; sub-threshold amplifier; Temperature dependence; Temperature sensors; Threshold voltage; Voltage
• ISSN: 1549-8328; 1558-0806
• DOI: 10.1109/TCSI.2015.2486078

When conventional biasing topologies are employed, near sub-threshold operated amplifiers show large performance deviations under unavoidable PVT variations. Moreover, these effects become severe when these circuits are implemented in sub-nanometer technologies. This paper introduces a new type of compensation technique to realize a reliable low voltage, low-noise amplifier that is achieved by stabilizing the core device trans-conductance (g m ). To minimize the g m variation, the proposed technique uses an error voltage generated by comparing the LNA current with a stable constant current reference (CCR). Not only the compensation circuits, a new low-voltage self-biased CCR source is also introduced which is based on conventional β multiplier that can operate with a voltage as low as 0.4 V with a resulting TC (temperature coefficient) of 118 ppm/°C for typical-typical corner case. The g m and S 21 of the compensated 65 nm LNA core device shows 8 × times lower variations compared to that of a conventional one when temperature varies from -20 to +110°C and with the consideration of five process corner cases. Finally, Monte Carlo estimation for both process and mismatch shows 34% reduction in standard deviation of S 21 and 20% improvement in yield compared to a conventionally biased LNA. The compensated LNA with all its accessories consumes only 402 μW power when operated at a supply voltage of 0.6 V.