Microchip Technology AT27C4096-12VC

Overview

AT27C4096-12VC from Atmel is a 4-Mbit (256K × 16) one-time programmable EPROM optimized for high-performance 16-/32-bit microprocessor systems, featuring 120 ns read access time, 5 V ±10% supply operation, and JEDEC-standard 40-lead VSOP (10 mm × 14 mm) packaging. It delivers low active current (40 mA max at 5 MHz) and ultra-low standby current (100 µA max), enabling firmware storage without mass-storage latency in embedded controllers and industrial firmware loaders.

For engineers reviewing the AT27C4096-12VC datasheet, AT27C4096-12VC pinout, AT27C4096-12VC application, or AT27C4096-12VC equivalent, key selection criteria include verified 120 ns tACC timing, dual-line CE/OE control architecture, Rapid™ programming (50 µs/word), integrated product identification code, and compatibility with legacy 512K–2M-bit EPROM upgrades.

Technical Context

The AT27C4096-12VC implements a CMOS OTP EPROM core with two-line control (CE and OE) to eliminate bus contention in high-speed systems. Its by-16 organization supports direct interface to 16-bit data buses, and its address range spans A0–A17 (18 address lines) for full 256K-word addressing.

It operates exclusively in 5 V ±10% supply mode with dedicated VPP pin (12.0 V ±0.5 V) for programming; read-mode VPP is tied to VCC. The device features CMOS/TTL-compatible I/O, 2,000 V ESD protection, and 200 mA latchup immunity-ensuring robustness in industrial environments.

Key Specifications

Pinout & Package

AT27C4096-12VC is packaged in a 40-lead Plastic Thin Small Outline Package (VSOP), 10 mm × 14 mm body, JEDEC MO-142 CA compliant, with 0.5 mm lead pitch and gull-wing terminations.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar OTP EPROM applications.

Compared with AT27C4096-12VC, the -12PC offers mechanical compatibility with legacy DIP sockets but sacrifices SMT scalability, while the -12JI provides identical industrial temp performance in a larger PLCC form factor-neither is pin-compatible, but all three share identical timing, programming, and functional behavior.

Availability

AT27C4096-12VC is available at Aetrix Electronics and suitable for industrial PLC firmware storage, medical device boot ROM, and automotive ECU calibration data requiring stable component supply across extended product lifecycles.

Supply support for AT27C4096-12VC includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Atmel Corporation (now part of Microchip Technology) is a fabless semiconductor company specializing in microcontrollers, non-volatile memory, and secure authentication ICs for industrial, automotive, and consumer applications.

The AT27C4096 belongs to Atmel's OTP EPROM product line, designed specifically to replace UV-erasable EPROMs with higher density, faster access, and simplified system integration in firmware-critical embedded systems.

FAQ

What is the maximum read access time specified for the AT27C4096-12VC?

The AT27C4096-12VC has a maximum read access time (tACC) of 120 ns under standard operating conditions (VCC = 5 V ±10%, TA = -40°C to +85°C). This value is guaranteed across the full industrial temperature range and is measured from address valid to valid data output with both CE and OE asserted low. The "-12" suffix in AT27C4096-12VC explicitly denotes this 120 ns speed grade.

Does the AT27C4096-12VC require a programming voltage during normal read operation?

No, the AT27C4096-12VC does not require an external programming voltage during read operation. In read mode, VPP is internally tied to VCC (5 V), and the device functions as a standard 5 V-only memory. The 12.0 V ±0.5 V VPP supply is required only during programming - and must be applied after VCC and removed before VCC per datasheet sequencing rules.

Can the AT27C4096-12VC be used as a direct replacement for the AT27C2048-12VC?

Yes, the AT27C4096-12VC is explicitly documented as a direct upgrade path from the AT27C2048 (2M-bit) EPROM. It shares identical pinout, voltage levels, timing architecture, and control signaling (CE/OE), allowing drop-in replacement in existing designs - provided the host system addresses the full 256K × 16 space and accommodates the increased memory depth.

What is the purpose of the Integrated Product Identification Code in the AT27C4096-12VC?

The Integrated Product Identification Code in the AT27C4096-12VC provides electrically readable Manufacturer ID (001Eh) and Device Code (00F4h) via dedicated A9 and A0 pin manipulation during power-up. This allows automated programming equipment to auto-detect the AT27C4096-12VC and select correct voltage, timing, and verification algorithms - eliminating manual setup errors in high-volume production.

How many ground connections does the AT27C4096-12VC require, and why?

The AT27C4096-12VC requires two dedicated ground connections - Pins 20 and 40 in the 40-lead VSOP package. Both must be connected to the system ground plane to ensure proper ESD current pathing, reduce ground bounce during high-speed output transitions, and maintain signal integrity across the 16-bit data bus. Leaving either unconnected violates the absolute maximum ratings and risks latchup or data corruption.