CP2102 USB-UART chip from SiLabs. Looks like around 350nm 3-metal process. Made at TSMC Fab 10 according to PCN 1011021

Appears to be a rebranded C8051F326 (also made by SiLabs) due to the part number on the die and the identical pinout.

Specs for the C8051F326:

• Full speed USB 2.0 device controller
• 25 MHz 8051 microcontroller core
• 1536 bytes RAM (1k data + 2x 256 byte USB FIFO)
• 16K bytes code/data flash
• UART
• GPIO

Package

Die