20 MHz core, 3.5 KB Flash — the memory budget is the first gate
The Microchip PIC16F872-I/SP is an 8-bit PIC® MCU in a 28-pin through-hole DIP package, built around a 20 MHz external-oscillator core. Its program memory is 3.5 KB (2K x 14 words) of Flash, backed by 128 bytes of RAM and 64 bytes of EEPROM — a footprint that fits small control loops, sensor readouts, and protocol bridging, but leaves no room for a large firmware stack or data buffer. The 22 available I/O lines and integrated 5-channel 10-bit ADC make it a natural fit for 8-bit control applications where a handful of analog inputs need to be digitized and acted upon over I²C or SPI.
Industrial temperature and 5 V supply — built for noisy environments
The on-chip Brown-out Detect and Power-on Reset peripherals help the firmware ride through supply glitches without a supervisor IC.
The part is ROHS3 compliant. For a legacy design that already qualifies this MCU, the supply channel is stable — no need to accelerate a last-time buy or requalify a drop-in replacement.