This paper describes an integrated communication
system, implementing a UWB-inspired pulsed coding technique,
for an optical transcutaneous biotelemetry. The system consists
of both a transmitter and a receiver facilitating a bidirectional
link. The transmitter includes a digital data coding circuit and is
capable of generating sub-nanosecond current pulses and directly
driving an off-chip semiconductor laser diode including all bias
and drive circuits. The receiver includes an integrated compact
PN-junction photodiode together with signal conditioning, de-
tection and digital data decoding circuits to enable a high bit
rate, energy efficient communication. The proposed solution has
been implemented in a commercially available 0.35
μ
m CMOS
technology provided by AMS. The circuit core occupies a compact
silicon footprint of less than 0.13 mm
2
(only 113 transistors and
1 resistor). Post-layout simulations have validated the overall
system operation demonstrating the ability to operate at bit rates
up to 500 Mbps with pulse widths of 300 ps with a total power
efficiency (transmitter + receiver) lower than 74 pJ/bit. This
makes the system ideally suited for demanding applications that
require high bit rates at extremely low energy levels. One such
application is implantable brain machine interfaces requiring
high uplink bitrates to transmit recorded data externally through
a transcutaneous communication channel.