CMOS oversampling Delta magnetic-to-digital converters

• Published in: IEEE journal of solid-state circuits 2001-10, Vol.36 (10), p.1582-1586
• Main Authors: Kuo, Chien-Hung, Chen, Shr-Lung, Ho, Lee-An, Liu, Shen-Iuan
• Format: Article
• Language: English
• ISSN: 0018-9200
• DOI: 10.1109/4.953488

In this paper, two CMOS oversampling delta-sigma (Delta) magnetic-to-digital converters (MDCs) are proposed. The first MDC consists of the magnetic operational amplifier (MOP) and a first-order switched-capacitor (SC) Delta modulator. The second one directly uses the MOP to realize a first-order SC Delta modulator. They can convert the external magnetic field into digital form. Both circuits were fabricated in a 0.5-mum CMOS double-poly double-metal (DPDM) process and operated at a 5-V supply voltage and the nominal sampling rate of 2.5 MHz. The dynamic ranges of these converters are at least +/-100 mT. The gain errors within +/-100 mT are less than 3% and the minimum detectable magnetic field can reach as small as 1 mT. The resolutions are 100 muT for both of the two MDCs. The measured sensitivities are 1.327 mv/mT and 0.45 mv/mT for the first and the second MDC, respectively