Title :
A Power-Efficient Highly Linear Reconfigurable Biopotential Sensing Amplifier Using Gate-Balanced Pseudoresistors
Author :
Tzu-Yun Wang ; Li-Han Liu ; Sheng-Yu Peng
Author_Institution :
Dept. of Electr. Eng., Nat. Taiwan Univ. of Sci. & Technol., Taipei, Taiwan
Abstract :
A low-power reconfigurable biopotential sensing amplifier with highly linear feedback pseudoresistors is presented. Due to the gate-balanced pseudoresistors, amplifier linearity has been significantly improved, achieving a dynamic range more than 62.8 dB, with total harmonic distortion better than 60 dB across the whole bandwidth. An array of proposed amplifiers was fabricated in a 0.35-μm CMOS process. Measured input-referred noise is 2.81 μV rms with a midband gain of 40.3 dB. The noise efficiency factors corresponding to the bandwidth settings of 100 Hz, 1 kHz, and 10 kHz are 1.88, 1.93, and 2.05, respectively. Using a supply voltage of 2.5 V, each amplifier consumes 3.6 μA of current to achieve a bandwidth of 10 kHz, with a dynamic range of 63.7 dB. The electrocardiogram (ECG) measurement results are shown in this brief to substantiate the necessary low-frequency linearity improvement.
Keywords :
CMOS integrated circuits; amplifiers; bioelectric potentials; biomedical electronics; electric sensing devices; electrocardiography; CMOS; ECG; bandwidth 100 Hz to 10 kHz; current 3.6 muA; electrocardiogram; gain 40.3 dB; gate-balanced pseudoresistors; input-referred noise; linear feedback pseudoresistors; low-frequency linearity improvement; noise efficiency factors; power-efficient highly linear reconfigurable biopotential sensing amplifier; size 0.35 mum; total harmonic distortion; voltage 2.5 V; voltage 2.81 muV; Bandwidth; Distortion measurement; Logic gates; Noise; Resistors; Sensors; Transistors; Floating-gate circuit; low power-amplifier; noise efficiency factor; pseudo-resistor; reconfigurable circuit;
Journal_Title :
Circuits and Systems II: Express Briefs, IEEE Transactions on
DOI :
10.1109/TCSII.2014.2387685
