Renesas AT25PE40-SHN-T

Overview

AT25PE40-SHN-T from Microchip Technology is a 4-Mbit serial Flash memory with SPI interface, RapidS™ high-speed operation up to 85 MHz, dual 256/264-byte SRAM buffers for concurrent read/write, and page/block/sector/chip erase granularity. It operates from 1.65V–3.6V and targets firmware storage, boot code, and embedded data logging in industrial controllers and IoT edge nodes.

For engineers reviewing the AT25PE40-SHN-T datasheet, AT25PE40-SHN-T pinout, AT25PE40-SHN-T application, or AT25PE40-SHN-T equivalent, key selection criteria include its 6 ns clock-to-output timing, 300 nA ultra-deep power-down current, user-selectable 256/264-byte page size, and hardware write-protect (WP) and reset (RESET) pins enabling robust in-system reprogramming in space-constrained designs.

Technical Context

The AT25PE40-SHN-T implements a sequential-access DataFlash-L® architecture with two independent SRAM buffers that enable interleaved buffering-allowing host systems to load new data into one buffer while the other is being programmed into main memory. Its SPI interface supports modes 0 and 3 with MSB-first transfer and self-timed erase/program cycles.

Memory organization comprises 2,048 pages of 256 bytes (default) or 264 bytes (customer-selectable), totaling 4,194,304 bits. Erase operations are supported at page (256/264 B), block (2 KB), sector (64 KB), and chip (4 Mbit) levels, with a 128-byte factory-programmed security register containing a unique identifier.

Key Specifications

Pinout & Package

AT25PE40-SHN-T is supplied in an 8-pad Ultra-thin DFN package (5 mm × 6 mm × 0.6 mm), RoHS-compliant and halide-free. The exposed metal pad on the bottom is not internally connected and may be left floating or tied to GND for thermal/mechanical stability.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT25PE40-SHN-T, AT25SF041-SSHD-T offers higher peak read speed but sacrifices buffer-assisted streaming, while W25Q40EWUXIE demands QSPI hardware and lacks RESET/WP pins-making AT25PE40-SHN-T uniquely suitable for cost-sensitive, SPI-only industrial designs needing concurrent operation and hardware safety controls.

Availability

AT25PE40-SHN-T is available at Aetrix Electronics and suitable for industrial PLC firmware storage, medical device boot code, and smart meter data logging requiring stable component supply across extended product lifecycles.

Supply support for AT25PE40-SHN-T 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 U.S.-based semiconductor company specializing in microcontrollers, analog devices, and non-volatile memory solutions for industrial, automotive, and communications markets.

The AT25PE40-SHN-T belongs to Microchip's DataFlash-L® family, designed specifically for embedded systems requiring high-speed sequential access, low-voltage operation, and hardware-controlled reliability features like WP and RESET.

FAQ

What is the default page size of the AT25PE40-SHN-T, and can it be changed?

The AT25PE40-SHN-T ships with a default page size of 256 bytes. A customer-selectable 264-byte page option is available at manufacturing time and cannot be changed in-circuit. This larger page size accommodates ECC parity bytes or protocol overhead without sacrificing usable payload capacity, and both configurations are fully supported by all erase, program, and read commands in the AT25PE40-SHN-T datasheet.

Does the AT25PE40-SHN-T support standard SPI mode 0 and mode 3 only, or are other modes compatible?

The AT25PE40-SHN-T explicitly supports only SPI modes 0 and 3, as confirmed in its official datasheet DS-25PE40-142D. Mode 0 (CPOL = 0, CPHA = 0) and mode 3 (CPOL = 1, CPHA = 1) define the clock polarity and phase used for reliable command and data transfer. Attempting mode 1 or mode 2 will result in incorrect opcode interpretation and failed operations - the AT25PE40-SHN-T does not auto-detect or adapt to unsupported modes.

How does the dual-buffer architecture of the AT25PE40-SHN-T improve system throughput?

The AT25PE40-SHN-T's two independent 256/264-byte SRAM buffers enable true interleaved operation: while Buffer 1 is being written to main memory via "Buffer to Main Memory Page Program", Buffer 2 simultaneously accepts new data from the host via "Buffer Write". This eliminates the traditional SPI Flash bottleneck where the host must idle during flash programming, increasing effective write throughput by up to 2× in continuous streaming applications such as audio logging or firmware patching.

Is the RESET pin on the AT25PE40-SHN-T mandatory for operation?

No, the RESET pin on the AT25PE40-SHN-T is optional. The device incorporates an internal power-on reset (POR) circuit, so normal initialization occurs without external RESET assertion. If unused, the RESET pin must be externally held high (e.g., via pull-up to VCC); leaving it floating is not recommended. Its primary value is in recovering from bus errors or terminating stuck operations - a feature especially useful in mission-critical industrial firmware loaders.

What is the purpose of the 128-byte Security Register in the AT25PE40-SHN-T?

The 128-byte Security Register in the AT25PE40-SHN-T is factory-programmed with a unique, unalterable device identifier. It is used for cryptographic binding, secure boot verification, and anti-counterfeiting in regulated applications. Unlike user memory, this register is read-only and immune to erase or program commands - ensuring consistent, tamper-proof identification across the full lifetime of the AT25PE40-SHN-T, even after 100,000+ program/erase cycles.