64 MHz 8-bit PIC with on-chip LCD drive
The Microchip PIC18F66K90-I/PT is an 8-bit PIC MCU from the PIC® XLP™ 18K family, built around a 64 MHz core that gives it a throughput edge over the 32 MHz 8- and 16-bit siblings in the same XLP portfolio. It carries 64KB of Flash program memory (32K x 16), 4K x 8 of RAM, and 1K x 8 of EEPROM for non-volatile parameter storage — enough headroom for a moderate control loop with a local data log. The standout peripheral is the integrated LCD segment driver, which lets a single chip run a segmented glass display without an external driver IC or a second MCU.
Rated for 1.8V to 5.5V on the Vdd rail, the PIC18F66K90-I/PT can run directly from a pair of alkaline cells or a regulated 3.3V supply, and it also tolerates legacy 5V logic rails without a level translator.
It is RoHS3 compliant. No official second-source alternate appears in the Microchip cross-reference, but the PIC24FV16KA304-I/PT (16-bit, 32 MHz, 16-channel 12-bit ADC) shares the same 64-TQFP footprint and peripheral set — a potential dual-source candidate for designs that can tolerate a 16-bit core migration.