An alternative to source degeneration of CMOS differential pair

作者：El Mourabit Aimad^*; Sbaa Mohamed Halim; Lu Guo Neng; Pittet Patrick

来源：Analog Integrated Circuits and Signal Processing, 2010, 62(3): 415-422.

DOI：10.1007/s10470-009-9339-1

• CMOS differential pair
• Transconductance
• MIFG-MOS
• Linear range
• Source degeneration

This paper presents a method to extend linear range of conventional CMOS source-coupled pair with transistor polarised on saturation of strong inversion. The used principle is similar to the principle of source degeneration, but the additional device is horizontally added, in parallel with the input transistors, which overcame the constraints on common mode range and supply voltage and allow low voltage operation. SPICE simulations using 0.35 mu m CMOS process and a bias current of 10 mu A, show that for less than 1% of transconductance variation, the linear range is up to 0.35 V(pp) in comparison to 0.1 V(pp) for source-degenerated pair, and 0.01 V(pp) for conventional differential pair, under the same biasing current and geometrical dimensions.

• 出版日期2010-3