Microchip Technology AT28C256-15JU-043

Overview

AT28C256-15JU-043 from Microchip Technology is an industrial-grade paged parallel EEPROM with 256-Kbit (32,768 × 8) organization, 150 ns read access time, single 5V ±10% supply operation, and JEDEC-approved byte-wide pinout. It supports 1–64-byte page writes with internal latching and automatic timing, and delivers 200 µA CMOS standby current for low-power embedded systems requiring nonvolatile configuration storage.

For engineers reviewing the AT28C256-15JU-043 datasheet, AT28C256-15JU-043 pinout, AT28C256-15JU-043 application, or AT28C256-15JU-043 equivalent, key selection criteria include page write cycle time (≤10 ms), hardware/software data protection, DATA Polling and Toggle Bit write completion detection, and compatibility with TTL/CMOS bus interfaces in legacy industrial controllers and instrumentation.

Technical Context

The AT28C256-15JU-043 implements a paged architecture with a 64-byte internal page register that latches address and data during write operations, freeing the bus for concurrent tasks. Its dual-line chip enable (CE) and output enable (OE) control enables flexible bus contention management in multi-device systems.

Write completion is verified via two independent methods: DATA Polling on I/O7 (complement-to-data during write, true data upon completion) and Toggle Bit behavior on I/O6 (toggling until write ends). Hardware protection includes VCC sense (<3.8 V inhibits write), 5 ms power-on delay, and noise filtering on WE/CE inputs.

Key Specifications

Pinout & Package

AT28C256-15JU-043 is packaged in a 32-lead PLCC (Plastic Leaded Chip Carrier) with JEDEC-standard byte-wide pinout. The package features gull-wing leads, 1.27 mm pitch, and conforms to MS-016 Variation AE. Pin 1 identifier is marked by a corner chamfer.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar paged parallel EEPROM applications.

Compared with AT28C256-15PU and AT28C256-15SU, the AT28C256-15JU-043 provides superior mechanical stability and thermal dissipation in harsh environments, making it the preferred choice for deployed industrial equipment where long-term reliability outweighs package size or assembly cost.

Availability

AT28C256-15JU-043 is available at Aetrix Electronics and suitable for industrial PLCs, legacy instrumentation, embedded bootloader systems, and automated test equipment requiring stable component supply and guaranteed 10-year data retention.

Supply support for AT28C256-15JU-043 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

Microchip Technology is a global semiconductor company specializing in microcontrollers, analog devices, and nonvolatile memory solutions, with a focus on industrial, automotive, and aerospace applications.

The AT28C256 product line delivers paged parallel EEPROMs optimized for legacy 8-bit system upgrades and industrial control applications requiring deterministic timing, hardware write protection, and extended temperature operation.

FAQ

What is the maximum page write size supported by the AT28C256-15JU-043?

The AT28C256-15JU-043 supports page write operations of 1 to 64 bytes. All bytes written within a single page write cycle must reside on the same 64-byte page, defined by address bits A6–A14. The internal page register latches the entire block, enabling efficient bulk programming without repeated address setup. This capability reduces host processor overhead compared to individual byte writes.

How does the AT28C256-15JU-043 indicate write completion?

The AT28C256-15JU-043 provides two hardware-verified methods: DATA Polling on I/O7 (returns complement of last written byte during write, then true data upon completion) and Toggle Bit behavior on I/O6 (toggles between 0 and 1 until write finishes). Both methods allow the host to poll asynchronously without fixed delays or external timers, ensuring deterministic timing in real-time systems.

Does the AT28C256-15JU-043 require external high-voltage circuitry for programming?

No, the AT28C256-15JU-043 operates from a single 5V ±10% supply for both read and write operations. High-voltage (12V) is only required for optional chip erase mode or accessing the 64-byte device identification area-neither function is needed for standard byte or page writes. Standard 5V logic levels fully control all normal read/write functions.

What is the purpose of the DC and NC pins on the AT28C256-15JU-043 PLCC package?

The DC (Don't Connect) and NC (No Connect) pins on the AT28C256-15JU-043 PLCC package (pins 1 and 17) have no internal bond wires and must remain unconnected. Per Microchip's datasheet, connecting these pins risks latch-up or undefined behavior. They exist solely for mechanical symmetry and package compatibility-not for signal routing or grounding.

Can the AT28C256-15JU-043 be used in systems with mixed TTL and CMOS logic families?

Yes, the AT28C256-15JU-043 features CMOS and TTL compatible inputs and outputs. Its input voltage thresholds (VIL ≤ 0.8 V, VIH ≥ 2.0 V) and output drive strength (VOL ≤ 0.45 V at 2.1 mA, VOH ≥ 2.4 V at -400 µA) meet both TTL and CMOS interface standards. This allows direct connection to legacy 5V microcontrollers, FPGAs, and peripheral ICs without level-shifting circuitry.