Mirrored Current-Conveyor Transimpedance Amplifier for Home Monitoring LiDAR Sensors

This article presents a current mode transimpedance amplifier (TIA) implemented in a standard 65-nm CMOS technology for the applications of elder-care home monitoring LiDAR sensors. Particularly, a novel mirrored current-conveyor (MCC) input configuration is proposed to lower the input impedance, thus achieving a wide bandwidth. This MCC-TIA can alleviate severe pulse spreading issue for near-range detection, enabling effective narrow-pulse recovery. Also, a feedforward control-voltage generator is newly suggested to realize an automatic gain-control within a single pulse-width duration. Measured results demonstrate the variable transimpedance gain of 59~77 dBQ to accommodate the incoming input currents of 18 μA
_pp
~ 2.24 mA
_pp
that corresponds to the feasible detection range of 0.5~5.3 meters in an elder's home. The bandwidth of 83 MHz~2.6 GHz is measured with the minimum noise current spectral density of 16.8 pA/sqrt(Hz). The chip dissipates 40 mW in total, and occupies the area of 1.0 mm
²
, including I/O pads.