We looked up this chip in 2021, right before we got smacked with a chip shortage and couldn’t get any to prototype with – but we’re back in biz and respinning a prototype up. While looking up the TLV320ADC quad microphone I2S ADC, we also bumped into the PCM1840. These chips are similar (almost identical pinout) but have analog-only inputs and no I2C or SPI configuration. Yep, it’s completely hardware pin bootstrapped, which makes setup much easier because you can use any I2S driver. It can act as an I2S controller (it clocks all I2S pins out) or the I2S peripheral (I2S clocks input and data is output). We whipped together a breakout to figure out how to get TDM I2S input working without dealing with the I2C setup. Looks awesome for spatial audio algorithms and voice recognition projects. You can pick up the PCM1840 ADC on DigiKey – lots are in stock!