Matched dual-channel front-end preamplifier for differential time delay measurements

Presented is an integrated circuit dual-channel front-end preamplifier that minimises the differential time delay (DTD) between two channels. The circuit, which is based on a chopper architecture, works in the audio range and is intended for applications in sound localisation based on bearing estimation. The circuit was fabricated in a 1.5 × 1.5 mm die, in a 0.5 μm technology. Experimental results indicate a mean DTD of 0.125 μs, which is one order of magnitude smaller than the experimental results reported in the literature so far.