IEEE-5333227 (pdf) In vivo testing of a low noise 32-channel wireless neural recording system
- 32 channels.
- Unique feature: analog-to-time PWM; digitization ciruitry is hence on the receiver.
- Even with this, 4.9 uV rms input-referred noise 1Hz-10kHz. Good!
- Another ASIC.
- 5.6mW at +- 1.5V, 3.3 x 3.0 mm^2.
- 1 bit adjustable gain; total gain 67 or 77dB.
- analog-to-time PWM just uses rail-to-rail comparators, activated by a circulating register.
- During each comparison, there is no digital transition anywhere on the chip, reducing substrate noise.
- this 640kHz TDM signal feeds a VCO -> FSK or OOK modulation.
- Custom receiver. USB.
- Need to measure THD & input referred noise on mine.
- -33dB crosstalk.
- Ghovanloo seems pretty good at citing himself.
____References____
Ming Yin and Seung Bae Lee and Ghovanloo, M. Engineering in Medicine and Biology Society, 2009. EMBC 2009. Annual International Conference of the IEEE 1608 -1611 (2009) |