A power-efficient reconfigurable amplifier with crossed cascode self-biasing

ABSTRACT

A low power reconfigurable sensing amplifier for biomedical applications is proposed. Two cascode voltages in a telescopic amplifier are provided by using only one floating gate and a symmetrically cross self-biasing scheme. Complementary differential pairs and floating-gate techniques are employed to attain low electronic noise and bandwidth reconfigurability with low power consumption. To improve linearity in low frequency operation, gate-balanced pseudo resistors are adopted as feedback resistors. The power efficiency is optimised using a 1.8 V supply voltage with 30 nA current consumption in a 100 Hz bandwidth setting. The measured noise efficiency factor (NEF) is 1.88 with $2.81 \mu {\mathrm{V}}_{\mathrm{r}ms}$ integrated input-referred noise. The dynamic range is above 61.7 dB.

KEYWORDS:

• Biopotential sensing amplifier
• low-power
• noise efficiency factor
• floating-gate circuit
• cascode biasing

Acknowledgements

This work was supported by the Ministry of Science and Technology in Taiwan under the project numbers of MOST 103-2221-E-011-174- and MOST 104-2221-E-011-118. The fabrication support provided by National Chip Implementation Center, Taiwan, and the Taiwan Semiconductor Manufacturing Company, Taiwan.

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Funding

This work was supported by the Ministry of Science and Technology in Taiwan [MOST 103-2221-E-011-174- and MOST 104-2221-E-011-118-].