Microchip Technology SST25VF040B-80-4I-QAE-T

Overview

SST25VF040B-80-4I-QAE-T from Microchip Technology is a 4 Mbit (512 K × 8) SPI serial flash memory IC designed for embedded code storage and data logging in resource-constrained systems. It operates from a single 2.7–3.6 V supply, supports up to 80 MHz high-speed read (via 0BH command), delivers 10 mA typical active read current, and features uniform 4 KByte sectors with 100,000 program/erase cycles endurance - deployed in industrial temperature range (−40°C to +85°C) for programmable logic controllers and firmware boot storage.

For engineers reviewing the SST25VF040B-80-4I-QAE-T datasheet, SST25VF040B-80-4I-QAE-T pinout, SST25VF040B-80-4I-QAE-T application, or SST25VF040B-80-4I-QAE-T equivalent, key selection considerations include its 80 MHz high-speed read capability, hardware RY/BY# status output via SO during AAI programming, industrial-grade temperature rating, and support for Auto Address Increment (AAI) word-programming to reduce firmware update time.

Technical Context

The SST25VF040B-80-4I-QAE-T implements a four-wire SPI interface compliant with Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), enabling interoperability with diverse microcontroller host interfaces. Its SuperFlash technology uses split-gate cells and thick-oxide tunneling injectors to achieve faster erase times (18 ms sector-erase typical) and lower total energy per operation versus conventional flash.

Internal control logic manages dual end-of-write detection: software polling of BUSY bit (bit 0) in the status register or hardware-driven RY/BY# status on SO pin when enabled via EBSY (70H) command - critical for deterministic timing in real-time firmware updates. Block protection is implemented via BP3–BP0 bits with lock-down via BPL bit, activated by WP# pin low.

Key Specifications

Pinout & Package

Package: 8-contact WSON (6 mm × 5 mm, QAE suffix), surface-mount, RoHS-compliant, optimized for high-density PCB layouts.

Key Features

Applications

Equivalent & Alternatives

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

Compared with W25Q40EW and S25FL004A, the SST25VF040B-80-4I-QAE-T uniquely combines 80 MHz read speed, AAI programming, hardware RY/BY# signaling, and 4 KByte sector erase - making it optimal for deterministic firmware updates and high-integrity logging in industrial and medical systems.

Availability

SST25VF040B-80-4I-QAE-T is available at Aetrix Electronics and suitable for industrial automation, medical diagnostics, and smart metering applications requiring stable component supply, long-term lifecycle assurance, and RoHS-compliant sourcing.

Supply support for SST25VF040B-80-4I-QAE-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 global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with deep expertise in embedded control and secure connectivity.

The SST25VF040B-80-4I-QAE-T belongs to Microchip's SST25VF serial flash product line, engineered specifically for cost-sensitive, space-constrained embedded systems needing reliable non-volatile storage with fast read performance and robust write management.

FAQ

What is the maximum clock frequency supported by SST25VF040B-80-4I-QAE-T for high-speed read operations?

The SST25VF040B-80-4I-QAE-T supports up to 80 MHz for High-Speed Read operations using the 0BH command with a dummy byte. This is confirmed in the DS25051A datasheet section "High-Speed-Read (50/80 MHz)" and applies specifically to the -80 variant. The -80 suffix denotes the 80 MHz speed grade, distinguishing it from the -50 (50 MHz) and -33 (33 MHz) versions. SST25VF040B-80-4I-QAE-T maintains timing compliance at this rate across its full industrial temperature range.

Does SST25VF040B-80-4I-QAE-T support Auto Address Increment (AAI) programming, and how does it improve firmware update efficiency?

Yes, SST25VF040B-80-4I-QAE-T fully supports AAI programming using the ADH (1010 1101b) command. It allows sequential word programming without retransmitting the address for each 2-byte write, reducing SPI bus traffic and host CPU overhead. As stated in the datasheet, AAI decreases total chip programming time significantly compared to Byte-Program mode - especially beneficial during full firmware image updates. SST25VF040B-80-4I-QAE-T implements both software (RDSR polling) and hardware (SO pin RY/BY#) end-of-write detection for AAI.

What package type is used for SST25VF040B-80-4I-QAE-T, and what are its key mechanical characteristics?

SST25VF040B-80-4I-QAE-T uses an 8-contact WSON (Wettable Flank Small Outline No-Lead) package measuring 6 mm × 5 mm (QAE suffix). It features exposed pad thermal enhancement, wettable flanks for automated optical inspection (AOI), and RoHS-compliant matte tin terminations. This package is distinct from the SOIC variants (200 mil and 150 mil) and is optimized for high-density PCB layouts and automated assembly. Pin assignments match the standard 8-pin SPI flash layout defined in Figure 2 of DS25051A.

How does the HOLD# pin function on SST25VF040B-80-4I-QAE-T, and when is it typically used?

The HOLD# pin on SST25VF040B-80-4I-QAE-T suspends an ongoing SPI transaction without deselecting the device or resetting internal state. When asserted low while CE# is active, it places SO in high-impedance and pauses clock synchronization - preserving the current address pointer and command context. It is commonly used in multi-master systems or when the host MCU must service higher-priority interrupts mid-transfer. SST25VF040B-80-4I-QAE-T requires SCK to be in its active-low state coincident with HOLD# falling edge for reliable entry into Hold mode, per Figure 4 of DS25051A.

What write protection mechanisms are available on SST25VF040B-80-4I-QAE-T, and how are they configured?

SST25VF040B-80-4I-QAE-T provides dual-layer write protection: hardware via the WP# pin (enabling BPL bit lock-down) and software via BP3–BP0 bits in the status register. When WP# is low, the BPL bit controls whether BP3–BP0 are read-only; when WP# is high, those bits are freely writable. Protection levels range from no protection to full 4 Mbit array lock, with granularity down to 4 KByte sectors (Table 4). SST25VF040B-80-4I-QAE-T defaults to full protection (BP3–BP0 = 111X) at power-up, requiring explicit WRSR to modify.