Microchip AT27C256R‑45 256 Kbit (32 K × 8) One‑Time Programmable (OTP) EPROM, 45 ns, 5 V, via DIP‑28 or PLCC package

The AT27C256R is a low‑power, one‑time programmable EPROM providing 256 Kbit (32 K × 8) non‑volatile memory. It operates from a single 5 V ±10 % supply and delivers byte reads in <45 ns, avoiding the need for wait states in high‑speed systems. The device uses CMOS technology for low active (~8 mA) and standby (<10 µA) current. It features a parallel interface with CE/OE control lines, TTL/CMOS compatibility, integrated product ID code, and robust ESD and latch-up immunity. Rated for −40 °C to +85 °C (industrial) operation.

Key Features:

• 256 Kbit (32K x 8-bit) one-time programmable memory structure
• Fast 45 ns access time for high-speed read operations
• Single +5 V power supply — no need for a programming voltage
• CMOS and TTL compatible inputs and outputs
• Low power consumption: <20 mA active, <100 µA standby
• Available in DIP-28 and PLCC-32 industry-standard packages