The LM3S5791-IBZ80-C3: The inclusion of I²S and QEI means this part was aimed at motor-control or audio-streaming endpoints where a dedicated serial audio interface and quadrature encoder input save external logic. On-chip analog is a 16-channel 10-bit A/D converter, adequate for reading potentiometers, current-sense resistors, or temperature sensors in a control loop. The internal oscillator eliminates an external crystal for non-critical timing, though the USB OTG peripheral will require a precision clock source for full-speed operation.
108-ball BGA — board integration notes
The 108-LFBGA package measures 10x10 mm with a 0.80 mm ball pitch. This is a fine-pitch BGA that demands a four-layer PCB minimum for fan-out — the inner rows route through vias-in-pad or dog-bone traces. The supplier device package (108-BGA) is the same footprint; confirm the solder-ball alloy and reflow profile against the moisture sensitivity level on the reel label before stenciling.
Obsolete — sourcing reality and lifecycle
Texas Instruments has marked the LM3S5791-IBZ80-C3 as obsolete. For a BOM that already carries this MCU, the remaining stock in the channel is the only drop-in path without a board spin.