Motor-control MCU in a through-hole DIP
The Microchip PIC18F4431-I/P is an 8-bit PIC® 18F microcontroller built for closed-loop motor and power-control applications. Its 40 MHz core drives a Power Control PWM module and a Quadrature Encoder Interface (QEI) — hardware blocks that offload the timing-critical commutation and position-feedback loops from firmware. The 16 KB Flash and 768 bytes of RAM are sized for a single motor-control algorithm plus a modest communications stack over I²C, SPI, or UART/USART. The 40-pin DIP package (0.600" body) is a through-hole part, so it survives rework cycles and breadboard prototyping without the risk of lifting a QFN pad.
5 V supply rail — no level shifting for legacy buses
The supply range of 4.2 V to 5.5 V means this MCU runs directly on a 5 V industrial rail. Sensors, encoders, and serial transceivers that also sit on 5 V need no level translators, which simplifies the BOM and keeps the board layout cleaner. The 36 I/O pins are 5 V-tolerant on the input side, so a 5 V backplane or a 24 V-to-5 V regulated sensor bus connects straight in.
Power Control PWM and QEI — hardware for motor loops
The Power Control PWM module generates complementary, dead-time-inserted gate drives for three-phase inverter bridges — the kind needed for BLDC or PMSM motor drives. The QEI decoder captures position and velocity from an incremental encoder without software polling. Together they let the 40 MHz CPU spend its cycles on the control law (PI, field-oriented) rather than bit-banging PWM edges or counting encoder pulses. The 9-channel 10-bit ADC samples current-sense resistors or Hall-effect sensors on the same cycle.
Through-hole DIP — rework-friendly, prototype-hardy
The 40-pin DIP (0.600" row spacing) is a through-hole package. It plugs into a standard socket or solders into plated through-holes. Under a hot-air station the part lifts cleanly — no hidden pads, no risk of pulling a land pattern. The 15.24 mm lead pitch gives good clearance for manual probing and scope-clip attachment during bring-up.
Microchip lists the PIC18F4431-I/P as Active. For dual-sourcing resilience, the PIC18F4431 family shares the same peripheral set across package options, so a TQFP-44 variant (PIC18F4431-I/PT) can serve as a drop-in footprint alternative if the board layout allows.