Title :
A remotely powered implantable IC for recording mouse local temperature with ±0.09 °C accuracy
Author :
Ghanad, Mehrdad A. ; Green, Michael M. ; Dehollain, Catherine
Author_Institution :
RFIC Group, Ecole Polytech. Fed. de Lausanne (EPFL), Lausanne, Switzerland
Abstract :
Multiple techniques are presented to implement an ultra-low-power remotely powered implantable system. The temperature is monitored locally by a thermistor-type sensor. The resistive response of the sensor is amplified and resolved in the time-domain. The data is transmitted using a duty cycled free running oscillator operating at 868 MHz. In addition, the sensor interface and data transmitter are time interleaved to improve power link sensitivity. A prototype chip is fabricated in 0.18 μm CMOS. The implant is powered with a 13.56 MHz inductive link and operates with a minimum power of 53 μW. The system is capable of recording temperature with accuracy of ±0.09 °C when 8 times oversampling is done at the base station.
Keywords :
CMOS integrated circuits; biomedical measurement; biothermics; energy harvesting; inductive power transmission; prosthetic power supplies; radiofrequency power transmission; temperature sensors; thermistors; CMOS integrated circuit; data transmitter; duty cycled free running oscillator; frequency 13.56 MHz; frequency 868 MHz; inductive link; mouse local temperature; power 53 muW; remotely powered implantable IC; size 0.18 mum; thermistor type sensor; ultralow power remotely powered implantable system; Accuracy; Oscillators; Regulators; Resistance; Temperature measurement; Temperature sensors; Transmitters;
Conference_Titel :
Solid-State Circuits Conference (A-SSCC), 2013 IEEE Asian
Conference_Location :
Singapore
Print_ISBN :
978-1-4799-0277-4
DOI :
10.1109/ASSCC.2013.6690990
