This document describes the features and characteristics of the EM78P257 8-bit microcontroller with OTP ROM. It is manufactured by ELAN Microelectronics Corp. and provides high reliability and stability.
The EM78P257 is an 8‑bit microcontroller featuring an on‑chip OTP ROM. It operates from 2.3 V to 5.5 V and is rated for temperatures between 0 °C and 70 °C. The device supports clock frequencies up to 20 MHz at 5 V (8 MHz at 3 V).
The datasheet details multiple package options, pin assignments, electrical specifications, and code options. Package outlines for 18‑pin and 20‑pin DIP, SOP and SSOP variants are provided, along with dimension tables and revision history.
| Operating Voltage | 2.3 V – 5.5 V |
|---|---|
| Maximum Clock Frequency (5 V) | 20 MHz |
| Maximum Clock Frequency (3 V) | 8 MHz |
The microcontroller operates from 2.3 V to 5.5 V.
Available packages include 18‑pin DIP (300 mil), 20‑pin DIP (300 mil), 18‑pin SOP (300 mil), 20‑pin SOP (300 mil) and 20‑pin SSOP (209 mil).
The device can run up to 20 MHz when supplied with 5 V.