USB Type-C controller with ARM Cortex-M0 — what it is and where it fits
The Infineon CYPD3135-40LQXI is a USB Type-C controller built around an ARM Cortex-M0 core with 128 KB of Flash program memory and 8K x 8 RAM.
128 KB Flash — firmware budget for PD policy
The 128 KB Flash holds the USB Power Delivery protocol stack, vendor-defined messages, and any custom policy engine.
Interface mix — I2C, SPI, UART, USB
The CYPD3135-40LQXI communicates with the host system over I2C or SPI for configuration and status, and uses UART for debug or firmware updates. The USB interface is the Type-C physical layer itself — the controller handles CC (Configuration Channel) detection, VBUS negotiation, and BMC (Biphase Mark Coding) encoding for PD messaging. On a motherboard, the I2C lines connect to an embedded controller or EC; in a standalone power adapter, the SPI port talks to a secondary MCU or flash for firmware storage. The 20 GPIOs can be mapped to LED indicators, load switches, or current-sense inputs.
Lifecycle: active production, no LTB risk
No last-time-buy or end-of-life notice applies. The part is RoHS3 compliant. For new designs, this means no forced redesign cycle from obsolescence; for production runs, the supply channel is stable through independent distribution.
Package and marking — what to check on receipt
The exposed pad must be soldered to a thermal land on the PCB for heat dissipation — the datasheet's recommended footprint shows the pad connection to ground. On incoming inspection, verify the laser-etched top mark matches Infineon's standard for the EZ-PD family: the date-code font and logo placement should be consistent across the reel or tray. Any variation in font, missing corner chamfer, or re-sanded surface is a red flag for gray-market re-marking.