The document describes the features and characteristics of a product.
The EM78P257 is an 8‑bit microcontroller built with low‑power, high‑speed CMOS technology. It includes a 2 K×13‑bit one‑time programmable ROM, multiple option bits, and a range of built‑in peripherals such as timers, comparators, and an RC oscillator.
The device is offered in 18‑lead and 20‑lead DIP and SOP packages, with detailed pin‑assignment tables, functional block diagrams, and electrical characteristic tables covering voltage, current, timing, and temperature ranges.
| Operating voltage range | 2.3 V ~ 5.5 V |
|---|---|
| Operating temperature range (commercial) | 0 °C ~ 70 °C |
| Operating temperature range (industrial) | -40 °C ~ 85 °C |
| Low power consumption at 5 V/4 MHz | < 1.5 mA |
| Typical standby current at 3 V/32 kHz | 15 pA |
| On‑chip ROM size | 2 K × 13 bits |
| General‑purpose registers | 80 × 8 bits (SRAM) |
| Stack depth | 8 levels |
| Watchdog timer | Programmable free‑running |
The EM78P257 operates from 2.3 V to 5.5 V.
The EM78P257AP DIP package has 18 pins.
Typical standby current is 15 pA at 3 V and 32 kHz.