Local field potentials (LFPs) are popularly used in wireless neural interface due to its chronic stability and robustness against noise and radio interferences. On-chip data compression is advantageous that allows for integration with the recent low-power, low-data-rate wireless technologies to ensure reliable operations. In this paper, we propose a streaming principal component analysis (PCA) based algorithm and its microchip implementation to compress multichannel LFP data. The chip has been designed in a 65nm CMOS technology and occupies a silicon area of 0.06mm2. It has been tested with Guinea pig auditory cortex data recorded with a multi-shank Neuro Nexus probe, where the chip can achieve an 8× compression ratio with ∼3% average reconstruction error, consuming 144nW per channel at a 0.5V power supply.