A Micro-Watt Second Order Filter for a Chopper Stabilized MEMS Pressure Sensor Interface
This paper describes a low-power second-order filter
for a continuous-time chopper stabilized capacitive sensor interface,
integrated with a fully differential post-CMOS surface-micromachined
MEMS pressure sensor. The circuit uses a single-ended
folded-cascode operational amplifier and two GM-C filters connected
in cascade. The circuit is realized in a 0.18 μm CMOS process and
offers differential to single-ended conversion. The novelty of the
scheme is the cascade of two GM-C filters to achieve a second-order
filter while minimizing power dissipation. The simulated filter cutoff
frequency is 1.14 kHz at common-mode voltage 1.65 V,
operating from a 3.3 V supply while dissipating 172μW of power.
The filter achieves an operating range of 1V for an output load of
1MOhm and 10pF.
[1] N. Ross and C. A. Eynon, "Intracranial pressure monitoring," Current
Anaesthesia & Critical Care, vol. 16, pp. 255-261, 2005
[2] N. Yazdi, H. Kulah, and K. Najafi, "Precision readout circuits for
capacitive micro-accelerometers," in Sensors, 2004. Proceedings of
IEEE, 2004, pp. 28-31 vol.1.
[3] W. Jiangfeng, G. K. Fedder, and L. R. Carley, "A low-noise low-offset
capacitive sensing amplifier for a 50╬╝g/ÔêÜHz monolithic CMOS MEMS
accelerometer," IEEE Journal of Solid-State Circuits, vol. 39, pp. 722-
730, 2004.
[4] C.C. Enz, E.A.Vittoz, and F. Krummenacher, "A CMOS chopper
amplifier," IEEE Journal of Solid-State Circuits, vol. 22, pp. 335-342,
1987.
[5] T. C. C. Kevin et.al, "118-dB dynamic range, continuous-time, openedloop
capacitance to voltage converter readout for capacitive MEMS
accelerometer," (A-SSCC) 2010, pp. 1-4.
[6] K. M. David A. Jones, "Analog Integrated Circuit Design," John Wiley
and Sons
[1] N. Ross and C. A. Eynon, "Intracranial pressure monitoring," Current
Anaesthesia & Critical Care, vol. 16, pp. 255-261, 2005
[2] N. Yazdi, H. Kulah, and K. Najafi, "Precision readout circuits for
capacitive micro-accelerometers," in Sensors, 2004. Proceedings of
IEEE, 2004, pp. 28-31 vol.1.
[3] W. Jiangfeng, G. K. Fedder, and L. R. Carley, "A low-noise low-offset
capacitive sensing amplifier for a 50╬╝g/ÔêÜHz monolithic CMOS MEMS
accelerometer," IEEE Journal of Solid-State Circuits, vol. 39, pp. 722-
730, 2004.
[4] C.C. Enz, E.A.Vittoz, and F. Krummenacher, "A CMOS chopper
amplifier," IEEE Journal of Solid-State Circuits, vol. 22, pp. 335-342,
1987.
[5] T. C. C. Kevin et.al, "118-dB dynamic range, continuous-time, openedloop
capacitance to voltage converter readout for capacitive MEMS
accelerometer," (A-SSCC) 2010, pp. 1-4.
[6] K. M. David A. Jones, "Analog Integrated Circuit Design," John Wiley
and Sons
@article{"International Journal of Electrical, Electronic and Communication Sciences:62846", author = "Arup K. George and Wai Pan Chan and Zhi Hui Kong and Minkyu Je", title = "A Micro-Watt Second Order Filter for a Chopper Stabilized MEMS Pressure Sensor Interface", abstract = "This paper describes a low-power second-order filter
for a continuous-time chopper stabilized capacitive sensor interface,
integrated with a fully differential post-CMOS surface-micromachined
MEMS pressure sensor. The circuit uses a single-ended
folded-cascode operational amplifier and two GM-C filters connected
in cascade. The circuit is realized in a 0.18 μm CMOS process and
offers differential to single-ended conversion. The novelty of the
scheme is the cascade of two GM-C filters to achieve a second-order
filter while minimizing power dissipation. The simulated filter cutoff
frequency is 1.14 kHz at common-mode voltage 1.65 V,
operating from a 3.3 V supply while dissipating 172μW of power.
The filter achieves an operating range of 1V for an output load of
1MOhm and 10pF.", keywords = "Chopper Stabilization, MEMS, Pressure Sensors,
Low Pass Filter", volume = "6", number = "9", pages = "1052-3", }