Microchip Technology AT93C56-10PI-1.8

Overview

AT93C56-10PI-1.8 from Microchip Technology (formerly Atmel) is a 2K-bit serial EEPROM with three-wire interface, supporting 1.8V to 5.5V operation and user-selectable 256 × 8 or 128 × 16 organization via the ORG pin. It delivers 2 MHz clock rate at 5V, 10 ms max self-timed write cycle, 1 million write endurance, and 100-year data retention. It is used in industrial control panels for storing calibration constants and configuration settings.

For engineers reviewing the AT93C56-10PI-1.8 datasheet, AT93C56-10PI-1.8 pinout, AT93C56-10PI-1.8 application, or AT93C56-10PI-1.8 equivalent, key selection considerations include low-voltage compatibility (1.8V min), internal organization flexibility, three-wire serial protocol timing compliance, standby current <0.1 µA at 1.8V, and PDIP-8 packaging for through-hole prototyping and legacy board replacement.

Technical Context

The AT93C56-10PI-1.8 implements a synchronous three-wire serial interface (CS/SK/DI/DO) with start-bit–driven instruction decoding and no external clock dependency beyond SK. Its dual-organization architecture allows runtime selection between byte-wide (256 × 8) and word-wide (128 × 16) memory mapping based on ORG pin voltage level.

Write operations require explicit EWEN enable prior to ERASE or WRITE instructions; all programming cycles are self-timed with Ready/Busy status reported on DO when CS is asserted post-initiation. The device supports full-array erase (ERAL) and write (WRAL), both restricted to VCC ≥ 4.5V, and maintains functional read capability regardless of erase/write state.

Key Specifications

Pinout & Package

AT93C56-10PI-1.8 is supplied in an 8-lead PDIP package (0.300" wide, JEDEC MS-001 BA compliant), suitable for through-hole mounting and manual rework. Pin 1 is marked by a notch or dot; orientation follows standard DIP convention with pin 1 in top-left corner when notch faces up.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95256-WMN6TP and 25AA020A-I/P, the AT93C56-10PI-1.8 offers lowest standby current at 1.8V, simplest GPIO-based interface, and deterministic 10 ms write latency - making it optimal for cost-sensitive, ultra-low-power, or resource-constrained designs where SPI/I²C peripherals are unavailable or oversubscribed.

Availability

AT93C56-10PI-1.8 is available at Aetrix Electronics and suitable for industrial control configuration storage, consumer appliance parameter retention, medical device calibration data, and automotive body control module settings requiring stable component supply and long-term obsolescence management.

Supply support for AT93C56-10PI-1.8 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 acquired Atmel in 2016 and maintains full technical and manufacturing continuity for the AT93C family of serial EEPROMs.

The AT93C56-10PI-1.8 belongs to Microchip's legacy serial EEPROM product line, designed specifically for cost-sensitive, low-pin-count embedded systems requiring reliable nonvolatile storage with minimal MCU resource usage.

FAQ

What is the minimum supply voltage required for reliable operation of the AT93C56-10PI-1.8?

The AT93C56-10PI-1.8 is rated for operation from 1.8V to 5.5V. At 1.8V, it guarantees full functionality including read, write, and erase operations, with standby current ≤0.1 µA and AC timing parameters met per Table 4 in the datasheet. Operation below 1.8V is not characterized and may result in data corruption or communication failure.

Can the AT93C56-10PI-1.8 be used interchangeably with the AT93C56-10PI-2.7 in a 3.3V system?

No - the AT93C56-10PI-1.8 and AT93C56-10PI-2.7 differ in their guaranteed 1.8V operation capability and input threshold specifications. While both function at 3.3V, the -1.8 version supports lower VIL/VIH thresholds optimized for 1.8V logic families, whereas the -2.7 version is characterized only down to 2.7V. Interchange requires verification of host controller voltage levels and timing margins.

How does the ORG pin affect memory addressing in the AT93C56-10PI-1.8?

When ORG is tied to VCC, the AT93C56-10PI-1.8 configures as 128 × 16 (16-bit words), requiring 7-bit addresses (A6–A0). When ORG is grounded, it configures as 256 × 8 (8-bit bytes), requiring 8-bit addresses (A7–A0). The ORG pin must be statically set before any instruction; dynamic switching during operation is not supported and may cause undefined behavior.

Is the AT93C56-10PI-1.8 compatible with modern RoHS-compliant assembly processes?

Yes - the AT93C56-10PI-1.8 is offered in lead-free/halogen-free variants (e.g., AT93C56-10PU-1.8) and its PDIP package meets JEDEC J-STD-020 moisture sensitivity level 1 (MSL-1), allowing unlimited floor life and standard reflow or wave soldering without baking. The -10PI-1.8 variant itself is leaded but remains compatible with selective soldering and hand assembly.

What happens if the EWEN instruction is omitted before a WRITE command on the AT93C56-10PI-1.8?

If EWEN is not executed prior to WRITE, the AT93C56-10PI-1.8 remains in Erase/Write Disable (EWDS) state and ignores the WRITE instruction. No data is altered, and DO outputs high-impedance during the attempted write. The host must issue EWEN first, then execute WRITE within the same CS low period or before issuing EWDS - otherwise the write attempt fails silently.