Microchip Technology AT25640A-10PU-1.8

Overview

AT25640A-10PU-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 operation, 20 MHz clock rate at 5 V, 32-byte page write mode, and hardware/software write protection via WP pin and status register. It serves as nonvolatile configuration storage in industrial controllers, sensor nodes, and power management ICs.

For engineers reviewing the AT25640A-10PU-1.8 datasheet, AT25640A-10PU-1.8 pinout, AT25640A-10PU-1.8 application, or AT25640A-10PU-1.8 equivalent, key selection criteria include low-voltage compatibility (1.8 V min), SPI Mode 0/3 support, block-level write protection granularity, self-timed 5 ms max write cycle, and JEDEC SOIC-8 packaging with RoHS-compliant lead finish.

Technical Context

The AT25640A-10PU-1.8 operates as a slave SPI peripheral with dedicated SI/SO lines, CS-controlled selection, and HOLD pin for transaction suspension without sequence reset. Its instruction set includes WREN/WRDI for write enable/disable, RDSR/WRSR for status register access, and READ/WRITE for memory access - all MSB-first with op-code–driven command decoding.

Block write protection is implemented via nonvolatile BP0/BP1 bits in the status register, enabling protection of 0%, 25%, 50%, or 100% of the memory array. Hardware write protection is conditional on WPEN bit = 1 and WP pin = low; WPEN=0 disables hardware protection regardless of WP state, allowing flexible system-level security design.

Key Specifications

Pinout & Package

AT25640A-10PU-1.8 is supplied in an 8-lead JEDEC SOIC package (8S1), 0.150" wide body, RoHS-compliant, green plastic with NiPdAu lead finish. Pin 1 is marked with a notch or dot; device orientation follows standard SOIC conventions.

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95640-DWDW3TP/K and 25AA640A-I/P, AT25640A-10PU-1.8 uniquely combines 1.8 V operation, HOLD functionality, and JEDEC SOIC-8 packaging with documented 100-year data retention - making it optimal for industrial IoT nodes where voltage scalability and transaction robustness are critical.

Availability

AT25640A-10PU-1.8 is available at Aetrix Electronics and suitable for industrial sensor calibration, motor drive configuration storage, smart energy meter firmware settings, and medical device safety parameter archiving requiring stable component supply across multi-year production cycles.

Supply support for AT25640A-10PU-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 product support, documentation, and manufacturing continuity for the AT25xxx family of serial EEPROMs.

The AT25640A-10PU-1.8 belongs to Microchip's legacy serial EEPROM product line, designed specifically for low-power, low-voltage embedded systems requiring reliable nonvolatile storage with SPI interface simplicity and robust data protection.

FAQ

What is the minimum operating voltage for AT25640A-10PU-1.8?

The AT25640A-10PU-1.8 supports true 1.8 V operation, with guaranteed functionality down to 1.8 V across the full industrial temperature range (–40°C to +85°C). This allows direct interfacing with 1.8 V microcontrollers and low-power ASICs without level-shifting circuitry. The device remains fully compliant with SPI timing specifications at 1.8 V, though maximum clock frequency is reduced compared to 5 V operation.

Does AT25640A-10PU-1.8 support SPI Mode 3 (CPOL=1, CPHA=1)?

Yes, AT25640A-10PU-1.8 explicitly supports both SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), as confirmed in the official datasheet Features section. This dual-mode capability ensures compatibility with microcontrollers that default to inverted clock polarity, such as certain NXP LPC and Renesas RX series devices, without requiring hardware modifications or software workarounds.

How does the WRITE PROTECT (WP) pin function in AT25640A-10PU-1.8?

In AT25640A-10PU-1.8, the WP pin provides hardware-level write inhibition when the WPEN bit in the status register is set to "1" and WP is driven low. When active, it blocks all writes to the status register (including BP bits and WPEN itself) and to memory regions covered by block protection. If WPEN=0, the WP pin is ignored - enabling flexible system integration where WP may be tied to ground without disabling configuration updates.

What is the maximum write cycle time for AT25640A-10PU-1.8?

The maximum write cycle time for AT25640A-10PU-1.8 is 5 ms, applicable across the full 1.8 V to 5.5 V supply range and –40°C to +85°C temperature range. This self-timed internal cycle eliminates the need for host-side delay loops or busy-wait polling; instead, firmware can issue RDSR commands to check the RDY bit (bit 0) and proceed only when the write completes.

Is AT25640A-10PU-1.8 RoHS-compliant and halogen-free?

Yes, AT25640A-10PU-1.8 is RoHS-compliant and halogen-free, as indicated by the "U" suffix in its ordering code. It features a green plastic package with NiPdAu lead finish, meeting JEDEC standards for environmentally conscious manufacturing. Full compliance documentation, including material declarations and test reports, is available through Microchip's product change notifications and quality portal.