Renesas AT25EU0021A-SSHN-B

Overview

AT25EU0021A-SSHN-B from Renesas Electronics is a 2-Mbit ultra-low-energy serial flash memory IC designed for SPI-based embedded storage in battery-constrained edge IoT and wearable systems. It operates across 1.65 V–3.6 V, supports 85 MHz max clock frequency, delivers 1.2 mA typical active read current, and enables eXecute-in-Place (XiP) execution. Its primary circuit role is non-volatile program/data storage with hardware-assisted security and flexible erase granularity.

For engineers reviewing the AT25EU0021A-SSHN-B datasheet, AT25EU0021A-SSHN-B pinout, AT25EU0021A-SSHN-B application, or AT25EU0021A-SSHN-B equivalent, key selection considerations include its SOIC-8 (150-mil) package, quad/dual/standard SPI mode support, 256-byte page erase capability, deep power-down (100 nA), and integrated 3×512-byte OTP security registers.

Technical Context

The AT25EU0021A-SSHN-B implements a configurable SPI interface supporting modes 0 and 3, with programmable dual- and quad-I/O operation enabled via Status Register 2's Quad Enable (QE) bit. Its architecture features independent 4/32/64 kB block erase and atomic 256-byte page erase - both with constant 8 ms typical timing - enabling efficient OTA updates and small-data logging without over-erasing.

It integrates three status registers (SR1–SR3) governing write protection, reset behavior, and I/O configuration, plus hardware HOLD/RESET and WP pins that double as IO3/IO2 in quad mode. Power management includes active, standby, and deep power-down (DPD) modes, with DPD entry/exit controlled by dedicated commands and validated at -40 °C to +85 °C.

Key Specifications

Pinout & Package

AT25EU0021A-SSHN-B is packaged in an industry-standard 8-pin SOIC (150-mil) body measuring 5.0 mm × 4.0 mm × 1.75 mm, RoHS-compliant and halogen-free.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W25Q20EW and MT25QL02GC, the AT25EU0021A-SSHN-B uniquely combines 1.65–3.6 V universal supply, 100 nA deep power-down, and OTP-secured registers - making it the only option qualified for multi-year battery-powered medical and industrial edge nodes requiring both security and energy efficiency.

Availability

AT25EU0021A-SSHN-B is available at Aetrix Electronics and suitable for smart wearables, industrial sensor nodes, edge gateways, and portable medical diagnostics requiring stable component supply, long-lifecycle support, and RoHS-compliant packaging.

Supply support for AT25EU0021A-SSHN-B 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 specializing in microcontrollers, analog, power, and memory solutions for automotive, industrial, and IoT markets.

The AT25EU0021A-SSHN-B belongs to Renesas' ultra-low-energy serial flash product line, engineered specifically for battery-constrained edge devices requiring secure, high-efficiency non-volatile storage with minimal system-level power overhead.

FAQ

What is the operating voltage range of the AT25EU0021A-SSHN-B?

The AT25EU0021A-SSHN-B operates across a wide 1.65 V to 3.6 V supply range, enabling direct compatibility with both 1.8 V and 3.3 V host microcontrollers without external level-shifting circuitry. This range is fully specified and tested per datasheet DS-AT25EU0021A-200 Rev. I, with stable operation confirmed across the entire industrial temperature range (-40 °C to +85 °C). The AT25EU0021A-SSHN-B maintains full functionality-including quad-SPI mode and security register access-within this voltage window.

Does the AT25EU0021A-SSHN-B support quad-SPI mode, and how is it enabled?

Yes, the AT25EU0021A-SSHN-B supports quad-SPI mode using commands such as Quad Output Fast Read (6Bh) and Quad I/O Fast Read (EBh). Activation requires setting the Quad Enable (QE) bit in Status Register 2 to '1' via the Write Status Register command. Once enabled, the WP and HOLD/RESET pins become IO2 and IO3, respectively, completing the four-line I/O bus. The AT25EU0021A-SSHN-B datasheet confirms this behavior on pages 9 and 12, with timing validated in Table 23.

What is the purpose of the HOLD/RESET pin on the AT25EU0021A-SSHN-B?

The HOLD/RESET pin on the AT25EU0021A-SSHN-B serves three distinct roles depending on configuration: (1) HOLD - pauses ongoing SPI communication without resetting internal state; (2) RESET - performs hardware reset when asserted low; (3) IO3 - functions as the third quad-SPI I/O line when QE=1. Its behavior is controlled by Status Register 3's HOLD/RESET bit and Status Register 2's QE bit. The AT25EU0021A-SSHN-B datasheet specifies all three modes in Section 2.1 and Table 1.

How does the AT25EU0021A-SSHN-B achieve ultra-low energy consumption?

The AT25EU0021A-SSHN-B achieves ultra-low energy consumption through constant-time 8 ms erase operations (independent of block size), 100 nA deep power-down current, and optimized 2 ms page programming. Its flexible 256-byte page erase avoids over-erasure during small-data writes, reducing total energy per update by >70% versus conventional flash. These characteristics are measured and guaranteed per DS-AT25EU0021A-200 Rev. I, Tables 7 and 19, and are central to the AT25EU0021A-SSHN-B's design for battery-operated edge IoT systems.

Is the AT25EU0021A-SSHN-B pin-compatible with other Renesas AT25EU-series flash devices?

No - the AT25EU0021A-SSHN-B is not pin-compatible with other AT25EU-series variants such as AT25EU0041A or AT25EU0081A, which differ in density, pin function mapping, and package options. While all share the same SOIC-8 (150-mil) footprint, the AT25EU0021A-SSHN-B's specific pin assignments (e.g., HOLD/RESET dual-function, IO2/IO3 remapping) and internal register layout are unique to the 2-Mbit variant. Pin compatibility is not claimed in DS-AT25EU0021A-200 Rev. I, and substitution requires full electrical and firmware validation.