The SX1503 is an i2c GPIO expander with support for 16 extra pins, 2 voltage translation banks, and some simple PLD functionality.

As far as I can tell, no other breakouts exist for this high-merit part. And soldering fine-pitch QFN parts is a serious headache for many hobbyists.

The part does not allow i2c address reassignment, so the only special features on the board are the decoupling capacitors with working voltages rated in excess of the SX1503's maximums.

Each board is tested prior to shipment.

UPDATE 2022.10.08

Semtech has killed another great part, and this one has reached the end of its life. I have purchased my last batch, and I will continue making breakouts in small quantities until they are gone. I will also continue to maintain the driver I've written for the SX1503. But if you are considering buying this part for evaluations in a new design, you ought to probably look elsewhere.