4-bit OTPROM MCU — fixed-code controller for mature designs
The HD4074849H is a 4-bit microcontroller with OTPROM program memory, designed for applications where the firmware is fixed at the factory and never updated in the field. The OTPROM architecture means the code is programmed once during manufacturing — no field reprogramming, no firmware updates. This makes the part a natural fit for high-volume, cost-sensitive embedded control in appliances, industrial timers, and simple human-machine interfaces where the control algorithm is stable and the BOM must be locked down.
Lifecycle and sourcing — still active, no obsolescence signal
What the OTPROM means for the BOM
OTPROM (one-time programmable read-only memory) locks the firmware at the programming step. There is no Flash or EEPROM for field updates, no bootloader for remote patching.