What the 25 MHz core and 96 KB Flash mean for your design
The MSP430F5526IRGCT: The core runs at 25 MHz. The 96 KB Flash is organized as 8-bit wide memory. The 8 KB RAM provides a buffer for firmware updates.
USB connectivity built in — no external PHY needed
This MCU integrates a USB 2.0 full-speed interface (12 Mbps) directly on-chip, with the transceiver and the controller. That saves a separate USB-to-UART bridge or a dedicated USB controller IC, which simplifies the BOM and frees up board area. The USB peripheral shares the pin set with other serial interfaces, so the design needs to allocate the USB D+ and D- pins early in the layout. The 47 I/O pins and internal oscillator allow designs to run without an external crystal for the core clock.
Without that via stitch, the junction temperature rises quickly above 85°C ambient at high I/O activity. The brown-out detect and POR peripherals are on-chip, so external reset supervisors are optional in most designs.