A 290 nW, weak inversion, Gm-C biquad

In this paper, a CMOS implementation of a low voltage micropower Gm-C biquad is presented. The filter is suitable for any kind of application involving low frequency ranges, and requiring very low power consumption, such as biomedical products. The Operational Transconductance Amplifier (OTA) is implemented with the devices working in the weak inversion saturation region, allowing the use of very small currents for low power purposes with reasonable aspect ratios which do not degrade the frequency response. The filter operates at a supply voltage lower than 1.75 V. Its cut-off frequency is tunable over two decades, and it exhibits a dynamic range higher than 54 dB, occupying an area of 0.06 mm/sup 2/ without the integrating capacitances.