Microchip Technology AT25320-10PI-2.7

Overview

AT25320-10PI-2.7 from Atmel (now Microchip) is a 32-Kbit SPI serial EEPROM organized as 4096 × 8-bit words, operating from 2.7V to 5.5V with 3.0 MHz max clock rate at 5V, 32-byte page write capability, and hardware/software write protection via WP pin and status register. It targets industrial control systems requiring nonvolatile parameter storage with low-power operation and robust data retention.

For engineers reviewing the AT25320-10PI-2.7 datasheet, AT25320-10PI-2.7 pinout, AT25320-10PI-2.7 application, or AT25320-10PI-2.7 equivalent, key selection criteria include voltage range compatibility (2.7–5.5 V), SPI Mode 0/3 support, 1 million write endurance, 100-year data retention, and 8-lead PDIP package with verified CS/SCK/SI/SO/WP/HOLD interface timing.

Technical Context

The AT25320-10PI-2.7 functions as a slave SPI peripheral with separate SI (input) and SO (output) pins, supporting MSB-first transmission and requiring WREN instruction before any write. Its internal architecture includes a nonvolatile status register controlling block write protection (BP0/BP1) and write protect enable (WPEN), with hardware protection active when WP is low and WPEN = 1.

It implements self-timed internal write cycles (5 ms typical), eliminates need for external erase commands, and supports HOLD pin to suspend ongoing serial transfers without resetting sequence state. Block protection covers 1/4, 1/2, or full memory array - mapped to address ranges 0x0C00–0x0FFF, 0x0800–0x0FFF, or 0x0000–0x0FFF respectively for the AT25320 variant.

Key Specifications

Pinout & Package

AT25320-10PI-2.7 uses an 8-lead PDIP (8P3) package: 0.300" wide body, 0.100" lead pitch, through-hole mounting. Pin 1 is CS (Chip Select), pin 2 is SO (Serial Output), pin 3 is WP (Write Protect), pin 4 is GND, pin 5 is VCC, pin 6 is HOLD, pin 7 is SCK (Serial Clock), and pin 8 is SI (Serial Input).

Key Features

Applications

Equivalent & Alternatives

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

Compared with M95320-WMN6TP and BR24T32FJ-WE2, the AT25320-10PI-2.7 offers verified HOLD functionality and pin-compatible PDIP footprint for legacy industrial designs, while maintaining identical 32-Kbit density and 2.7–5.5 V operation - making it optimal for drop-in replacement where SPI timing and hardware suspend capability are critical.

Availability

AT25320-10PI-2.7 is available at Aetrix Electronics and suitable for industrial automation, automotive electronics, and medical instrumentation requiring stable component supply, long-lifecycle support, and verified PDIP packaging for through-hole manufacturing.

Supply support for AT25320-10PI-2.7 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, designs high-reliability nonvolatile memory and microcontroller solutions for industrial, automotive, and consumer applications.

The AT25320-10PI-2.7 belongs to the AT25xxx SPI EEPROM product line, engineered for low-voltage, low-power embedded systems needing robust, pin-efficient serial memory with hardware write protection and industrial temperature operation.

FAQ

What is the memory organization of the AT25320-10PI-2.7?

The AT25320-10PI-2.7 contains 32,768 bits of EEPROM memory organized as 4096 words × 8 bits each. This structure supports byte-addressable reads and writes, with address range 0x0000 to 0x0FFF. The AT25320-10PI-2.7 uses a 12-bit address space, and its page write capability allows up to 32 consecutive bytes to be written in a single operation without intermediate CS toggling.

Does the AT25320-10PI-2.7 support both SPI Mode 0 and Mode 3?

Yes, the AT25320-10PI-2.7 explicitly supports SPI Modes 0 (CPOL = 0, CPHA = 0) and 3 (CPOL = 1, CPHA = 1). In Mode 0, data is sampled on the rising edge of SCK and shifted on the falling edge; in Mode 3, sampling occurs on the falling edge and shifting on the rising edge. The AT25320-10PI-2.7 does not support Modes 1 or 2, and its behavior is defined only for these two configurations per the datasheet.

How does hardware write protection work on the AT25320-10PI-2.7?

Hardware write protection on the AT25320-10PI-2.7 activates when the WP pin is driven low AND the WPEN bit in the status register is set to 1. When enabled, this combination inhibits all writes to the status register and to memory blocks selected by BP0/BP1. The AT25320-10PI-2.7 remains readable, and unprotected memory regions remain writable. If WPEN = 0, the WP pin has no effect - allowing flexible system integration even with WP tied to ground.

What is the typical write cycle time for the AT25320-10PI-2.7?

The AT25320-10PI-2.7 has a typical internal write cycle time of 5 ms, with a maximum of 10 ms over temperature and voltage. This self-timed operation means no external delay is needed after issuing a WRITE command - the device automatically manages programming timing. During this period, only the RDSR (Read Status Register) instruction is accepted; all other commands are ignored until RDY bit clears.

Is the AT25320-10PI-2.7 compatible with 1.8 V systems?

No, the AT25320-10PI-2.7 is specifically rated for 2.7 V to 5.5 V operation, as indicated by the "-2.7" suffix in its ordering code. For 1.8 V systems, Atmel offers the AT25320-10PI-1.8 variant, which supports 1.8 V to 5.5 V. Using the AT25320-10PI-2.7 below 2.7 V may result in unreliable read/write operations or failure to meet AC timing specifications.