A 16-{micro}A interface circuit for a capacitive flow sensor

Journal Article · Tue Dec 01 00:00:00 EST 1998 · IEEE Journal of Solid-State Circuits

DOI:https://doi.org/10.1109/4.735555· OSTI ID:343671

Rodgers, B; Yunus, M ^[1]; Goenawan, S ^[2]; Kaneko, Yoshikazu; Yoshiike, Junichi ^[3]

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1. Integrated Sensor Solutions, San Jose, CA (United States)
2. Marvell Semiconductor, Sunnyvale, CA (United States)
3. Nagano Keiki Co., Ltd. (Japan)

A micropower interface circuit is described for fluidic flow measurement in commercial gas meters. The application-specific integrated circuit converts dynamic capacitive-flow sensor readings from 1 to 150 Hz into digital pulses suitable for reading by the host microcontroller. The signal path is first-order {Delta}{Sigma} modulation followed by a three-pole, one-zero infinite impulse response bandpass filter. Analog signal processing is fully differential switched capacitor, with amplifiers and dc current consuming blocks operating in weak inversion. Chip bias and oscillator frequency, and capacitive sensor offset and gain, are trimmed with on-chip EEPROM. Operating ranges are 2.5--3.6 V and from {minus}10 to 65 C, with active I{sub dd} of 16 {micro}A.

• OSTI ID: 343671
• Journal Information: IEEE Journal of Solid-State Circuits, Vol. 33, Issue 12; Other Information: PBD: Dec 1998
• Country of Publication: United States
• Language: English

Related Subjects

32 ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION
GAS METERS
ANALOG-TO-DIGITAL CONVERTERS
TRANSDUCERS
DIGITAL FILTERS
INTEGRATED CIRCUITS