This paper presents a power, speed and area optimized mini-LED driver integrated in 180 nm CMOS HV process and capable of sinking up to 4mA current. It aims to cover various applications of optoelectronic implants with a single design. The current driver consists of a drain-regulated self-cascode current mirror. An additional carrier sweep-out circuit reduces the mini-LED voltage fall time down to 4.7 ns. The current can be digitally adjusted from 0.5 mA to 4 mA, depending on its use-case. The temperature-compensated current reference provides 0.01 mA with a temperature coefficient (TC) of 210 ppm/°C between -10 °C and 110 °C leading to a TC of 357 ppm/°C for the output current. The successfully performed measurements for circuit under pad constructs revealed a possible size reduction only limited by the dimensions of the on-die processed mini-LEDs of 0.1 mm x 0.2 mm.

A compressed sensing integrate-and-fire neuron concept for massively parallel recordings is presented which expands the fundamental idea of superimposing timely sparse signals for data compression to any kind of continuous-time signals. Merging compressed sensing and amplitude-to-spike conversion, the proposed approach increases the information density and reduces the channel load. Combining multiple data-compressive neurons as a sensing array, further compression can be achieved when the spikes from different recording sites are superimposed on a single transmission channel. Signal reconstruction quality and transmission channel load are investigated to provide a strategy for selecting the design parameters of the proposed system. A proof-of-concept is presented, where a load per recording channel of 1 % under a relative reconstruction error of 0.32 % (SNR = 25 dB) is achieved.

Integrating sensors within a complete readout system on a single die has become essential to the More-than-Moore philosophy. Mechanical stress, as one of the physical quantities of potential interest, provides various information from simple static to dynamic load. Integration of piezoresistive elements within a complete CMOS system has been achieved in many ways, and ground-laying effects have been studied and described in detail. To bring the mechanical and electrical domains closer together, a new concept is presented that allows an analytical and simulation-based approximation of the sensors’ behavior due to applied mechanical stress as part of established concepts in electronics. It is evaluated based on measured state-of-the-art sensor implementations and used to bring up an alternative architecture with enhanced and on-the-fly adaptive sensitivity. Simulations are used to then further evaluate any model errors due to second-order effects that have been neglected within the design process.