Article

A 350 W CMOS MSK Transmitter and 400 W OOK Super-Regenerative Receiver for Medical Implant Communications

Microsyst. Technol. Labs., Massachusetts Inst. of Technol., Cambridge, MA
IEEE Journal of Solid-State Circuits (impact factor: 3.23). 05/2009; DOI:10.1109/JSSC.2009.2014728 pp.1248 - 1259
Source: IEEE Xplore

ABSTRACT Recent advances in the medical field are spurring the need for ultra-low power transceivers for wireless communication with medical implants. To deal with the growing demand for medical telemetry, the FCC commissioned the medical implant communications services (MICS) standard in 1999 in the 402-405 MHz band. This paper presents a 350 muW FSK/MSK direct modulation transmitter and a 400 muW OOK super-regenerative receiver (SRR) specifically optimized for medical implant communications. The transceiver is implemented in 90 nm CMOS and digitally tunes 24 MHz in frequency steps smaller than 2 kHz. The transmitter meets MICS mask specifications with data rates up to 120 kb/s consuming only 2.9 nJ/bit; the receiver has a sensitivity better than -99 dBm with a data rate of 40 kb/s or -93 dBm with a data rate of 120 kb/s consuming 3.3 nJ/bit. A frequency correction loop incorporating the base-station is prototyped to eliminate the need for a frequency synthesizer in the implant while still achieving frequency stability of less than 3 ppm.

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Keywords

2 kHz
 
3 ppm
 
350 muW FSK/MSK direct modulation transmitter
 
400 muW OOK super-regenerative receiver
 
base-station
 
data rate
 
data rates
 
digitally tunes 24 MHz
 
frequency correction loop incorporating
 
frequency stability
 
growing demand
 
implant
 
medical implant communications
 
medical implant communications services
 
medical implants
 
wireless communication
 

J.L. Bohorquez