A 0.18µm CMOS switched-capacitor amplifier using current-starving inverter based op-amp for low-power biosensor applications

Silicon biosensor arrays for the generation of chemical images have been proposed for the study of cell migration and tissue development. In order for these arrays to be viable they need highly accurate and low-power read channels. Low-power designs are key to making sure that heat generated by the silicon chip does not affect the bio-samples being tested. This paper presents an ultra-low power switched capacitor amplifier design for use in such a biosensor system. The amplifier was designed using a commercial 0.18μm process with a reduced supply voltage of 0.9V to minimize power consumption. The amplifier has an input signal bandwidth of 1kHz and consumes only 4μW with a 1MHz sampling rate. The total harmonic distortion (THD) of the amplifier output is -67.68dB resulting in an effective resolution of 10.96 bits.