Capacitive Readout Circuit for Tri-axes Microaccelerometer with Sub-fF Offset Calibration
| Autor: | Jungryoul Choi, Jungwoo Lee, Seunghyun Lim, Jindeok Seo, Sangyun Han, Changho Seok, Sung-Wook Kim, Hyunkyu Ouh, Hyunho Kim, Kyomuk Lim, Hyoungho Ko |
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| Rok vydání: | 2014 |
| Předmět: |
Microelectromechanical systems
Correlated double sampling Offset (computer science) Materials science business.industry Electrical engineering Linearity Capacitive readout Electronic Optical and Magnetic Materials law.invention Capacitor Least significant bit law Electrical and Electronic Engineering business Voltage |
| Zdroj: | JSTS:Journal of Semiconductor Technology and Science. 14:83-91 |
| ISSN: | 1598-1657 |
| DOI: | 10.5573/jsts.2014.14.1.083 |
| Popis: | This paper presents a capacitive readout circuit for tri-axes microaccelerometer with sub-fF offset calibration capability. A charge sensitive amplifier (CSA) with correlated double sampling (CDS) and digital to equivalent capacitance converter (DECC) is proposed. The DECC is implemented using 10-bit DAC, charge transfer switches, and a chargestoring capacitor. The DECC circuit can realize the equivalent capacitance of sub-fF range with a smaller area and higher accuracy than previous offset cancelling circuit using series-connected capacitor arrays. The readout circuit and MEMS sensing element are integrated in a single package. The supply voltage and the current consumption of analog blocks are 3.3 V and 230 μA, respectively. The sensitivities of tri-axes are measured to be 3.87 mg/LSB, 3.87 mg/LSB and 3.90 mg/LSB, respectively. The offset calibration which is controlled by 10-bit DECC has a resolution of 12.4 LSB per step with high linearity. The noise levels of tri-axes are 349 μg/√Hz, 341 μg/√Hz and 411 μg/√Hz, respectively. |
| Databáze: | OpenAIRE |
| Externí odkaz: |
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