A Standard-Cell-Based Neuro-Inspired Integrate-and-Fire ATC for Biological and Low-Frequency Signals

Continuous-time (CT) asynchronous data converters namely, ADCs and analog-to-time converters (ATCs), can be beneficial for certain types of applications, such as, processing of biological signals with sparse information. A particular case of these converters is the integrate-and-fire converter (IFC) that is inspired by the neural system. This paper presents a standard-cell-based (SCB) open-loop IFC circuit, designed and prototyped in a 130 nm CMOS standard process. It has a power dissipation of 59 µW and an energy per pulse of 18 pJ, which is one of the lowest energy per pulse consumption reported for IFC circuits, without requiring an external clock. The maximum pulse density (average firing-rate) is 3300 kHz. It is mostly digital, using only two additional on-chip integrating capacitors.