Microchip Technology AT25640AN-10SU-1.8

Overview

AT25640AN-10SU-1.8 from Microchip Technology (formerly Atmel) is a 64 Kbit SPI serial EEPROM organized as 8192 × 8-bit memory, supporting 1.8 V to 5.5 V supply, 20 MHz clock at 5 V, 32-byte page write, and hardware/software write protection. It serves as nonvolatile configuration storage in industrial controllers, sensor nodes, and power management ICs.

For engineers reviewing the AT25640AN-10SU-1.8 datasheet, AT25640AN-10SU-1.8 pinout, AT25640AN-10SU-1.8 application, or AT25640AN-10SU-1.8 equivalent, key selection criteria include low-voltage operation down to 1.8 V, block-level write protection (1/4, 1/2, or full array), HOLD pin for serial communication suspension, and JEDEC SOIC-8 packaging with RoHS compliance.

Technical Context

The AT25640AN-10SU-1.8 operates as an SPI slave device with separate SI and SO pins, supporting only Modes 0 (0,0) and 3 (1,1), with Mode 0 explicitly documented. Its internal architecture includes an 8-bit instruction register, nonvolatile status register (BP0/BP1/WPEN), and automatic address increment during page writes.

Write enable requires explicit WREN instruction prior to WRITE or WRSR; all programming cycles are self-timed (≤5 ms), require no pre-erase, and support RDY/BUSY polling via RDSR. The HOLD pin suspends ongoing transfers without resetting the sequence, while WP enables hardware lock of status register and protected memory blocks when WPEN = 1.

Key Specifications

Pinout & Package

AT25640AN-10SU-1.8 is packaged in an 8-lead JEDEC SOIC (8S1), 0.150" wide body, RoHS-compliant, green package with NiPdAu lead finish.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95640-DW and BR24G64FJ-3GE2, AT25640AN-10SU-1.8 uniquely delivers SPI HOLD capability and dedicated WP pin for hardware-enforced status register locking - critical for deterministic real-time systems and safety-certified designs requiring guaranteed write inhibition.

Availability

AT25640AN-10SU-1.8 is available at Aetrix Electronics and suitable for industrial PLCs, smart sensors, power management ICs, medical devices, and automotive body control modules requiring stable component supply across extended temperature and long-lifecycle programs.

Supply support for AT25640AN-10SU-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 is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with broad industrial and automotive qualification coverage.

AT25640AN-10SU-1.8 belongs to Microchip's legacy AT25xxx serial EEPROM family, designed specifically for robust, low-power, SPI-based nonvolatile storage in harsh environments and safety-critical applications.

FAQ

What is the maximum clock frequency supported by AT25640AN-10SU-1.8 at 1.8 V supply?

At VCC = 1.8 V, the AT25640AN-10SU-1.8 supports up to 5 MHz SCK frequency, as specified in Table 1-3 AC Characteristics. This is lower than its 20 MHz rating at 5 V due to reduced drive strength and timing margins at minimum voltage. Designers must configure their SPI master accordingly to avoid setup/hold violations.

Does AT25640AN-10SU-1.8 support SPI Mode 1 or Mode 2?

No. The AT25640AN-10SU-1.8 explicitly supports only SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1), with Mode 0 operation fully documented in the datasheet. Modes 1 and 2 are not functional and will result in communication failure or undefined behavior.

How does the HOLD pin behave during an active write cycle?

The HOLD pin remains functional during an internal write cycle: asserting HOLD low pauses the serial interface, but the write operation continues autonomously. The SO pin goes high-impedance, and the device ignores SI inputs until HOLD is deasserted and CS is toggled. RDSR remains accessible to poll RDY status.

Can AT25640AN-10SU-1.8 be used in automotive applications?

Yes - the AT25640AN-10SU-1.8 is qualified for automotive use per the "Available in Automotive" feature statement and operates across –40°C to +125°C (Absolute Maximum Ratings). However, for AEC-Q100 qualified designs, users must verify grade-specific testing (e.g., Grade 2 or 3) with Microchip's official automotive documentation.

What happens if more than 32 bytes are written in a single page write command to AT25640AN-10SU-1.8?

If more than 32 bytes are transmitted in one WRITE sequence, the internal address counter rolls over after byte 32, causing subsequent data to overwrite the first bytes of the same page. No error is generated; the device completes the write cycle normally. This behavior requires firmware to enforce strict 32-byte boundaries.