A Charge-Based CMOS Parallel Analog Vector Quantizer

Abstract

We present an analog VLSI chip for parallel analog vector quantization. The MOSIS 2.0 μm double-poly CMOS Tiny chip contains an array of 16 x 16 charge-based distance estimation cells, implementing a mean absolute difference (MAD) metric operating on a 16-input analog vector field and 16 analog template vectors. The distance cell including dynamic template storage measures 60 x 78 μm^2. Additionally, the chip features a winner-take-all (WTA) output circuit of linear complexity, with global positive feedback for fast and decisive settling of a single winner output. Experimental results on the complete 16 x 16 VQ system demonstrate correct operation with 34 dB analog input dynamic range and 3 μsec cycle time at 0.7 mW power dissipation.