Renesas AT45DB321E-DWF

Overview

AT45DB321E from Renesas Electronics is a 32-Mbit serial DataFlash memory with 1-Mbit extra buffer space, operating from 2.3 V to 3.6 V and supporting SPI modes 0 and 3. It delivers up to 85 MHz read speed, 6 ns clock-to-output time, and features dual 512/528-byte SRAM buffers for interleaved write operations-enabling continuous data streaming in embedded voice, firmware, and image storage systems.

For engineers reviewing the AT45DB321E datasheet, AT45DB321E pinout, AT45DB321E application, or AT45DB321E equivalent, key selection criteria include RapidS™ high-speed interface support, programmable 512/528-byte page size, hardware/software sector protection, ultra-deep power-down (400 nA), and JEDEC-standard manufacturer/device ID read capability.

Technical Context

The AT45DB321E implements a serial sequential-access architecture with two independent SRAM buffers, enabling concurrent buffer write and main memory page program operations. Its memory array comprises 8,192 pages (512 or 528 bytes each), totaling 34,603,008 bits (32 Mbit + 1 Mbit extra), and supports full erase granularity from page (512/528 B) to chip (32 Mbit).

It integrates hardware-controlled write protection via WP pin and software-configurable sector lockdown, plus a 128-byte OTP security register with 64 bytes factory-programmed unique ID. All program/erase cycles are self-timed, requiring no external high-voltage supply.

Key Specifications

Pinout & Package

AT45DB321E-DWF uses an 8-pad Ultra-thin DFN package (5 × 6 × 0.6 mm), RoHS-compliant and halide-free. Pin functions are validated per Renesas DS-AT45DB321E-8784 Rev. N, Page 7.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AT45DB321D-SU and W25Q32JVSIM, the AT45DB321E-DWF uniquely combines ultra-low deep-power-down current, dual-SRAM-buffer streaming, and factory-programmed UID in a compact UDFN package-making it optimal for battery-powered, firmware-plus-data co-storage applications demanding security and endurance.

Availability

AT45DB321E-DWF is available at Aetrix Electronics and suitable for firmware storage, audio logging, secure identity provisioning, and embedded configuration management requiring stable component supply across industrial, medical, and IoT product lifecycles.

Supply support for AT45DB321E-DWF 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

Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and IoT markets.

The AT45DB321E belongs to the DataFlash® family, designed specifically for high-reliability, low-pin-count sequential data storage where SPI simplicity, streaming efficiency, and integrated security outweigh random-access requirements.

FAQ

What is the maximum clock frequency supported by AT45DB321E during continuous array read?

The AT45DB321E supports up to 85 MHz during continuous array read in RapidS™ high-frequency mode (opcodes 0Bh or 1Bh). This is confirmed in the datasheet's AC Characteristics table (Page 60) and Read Commands section (Page 13). The 6 ns clock-to-output time (tV) enables reliable timing at this rate. Standard SPI mode (03h) operates up to 66 MHz, while low-power mode (01h) caps at 15 MHz.

Does AT45DB321E-DWF support true byte-level programming like EEPROM?

No, AT45DB321E does not support direct byte-level programming. However, it enables E2PROM emulation through a self-contained three-step read-modify-write operation using its dual SRAM buffers-allowing bit or byte alteration within a page without external MCU intervention. This is explicitly described in the Description section (Page 6) and Section 7.6.

What package type is used for AT45DB321E-DWF, and what are its dimensions?

AT45DB321E-DWF uses the 8-pad Ultra-thin DFN (UDFN) package, measuring 5 mm × 6 mm × 0.6 mm (DS-AT45DB321E-8784, Page 76). It is RoHS-compliant, halide-free, and features an exposed thermal pad on the bottom that may be left unconnected or tied to GND for improved thermal performance.

How does the AT45DB321E handle power-loss during programming or erase operations?

The AT45DB321E incorporates robust power-loss immunity: all program and erase cycles are self-timed and internally managed. If power drops mid-operation, the device retains its pre-operation state-no partial writes or corrupted sectors occur. Status register bit 7 (RDY/BUSY) indicates ongoing activity, allowing host firmware to delay power-down until completion (Section 18.4, Page 60).

Can the page size of AT45DB321E be changed after initial configuration?

Yes-the AT45DB321E supports runtime reconfiguration of page size between 512 bytes (binary mode) and 528 bytes (standard DataFlash mode) using Buffer and Page Size Configuration commands (Table 22, Page 46). This change affects addressing and command sequences but does not require factory reprogramming or device replacement.