Microchip Technology SST25VF040B-80-4I-S2AE

Overview

SST25VF040B-80-4I-S2AE from Microchip Technology is a 4 Mbit (512 K × 8) SPI serial flash memory IC with SuperFlash® technology, supporting up to 80 MHz high-speed read, single 2.7–3.6 V supply operation, and industrial temperature range (–40°C to +85°C). It delivers fast byte-program (7 µs typ), sector/block/whole-chip erase (18 ms / 18 ms / 35 ms typ), and Auto Address Increment (AAI) programming for efficient firmware updates in embedded microcontroller boot storage.

For engineers reviewing the SST25VF040B-80-4I-S2AE datasheet, SST25VF040B-80-4I-S2AE pinout, SST25VF040B-80-4I-S2AE application, or SST25VF040B-80-4I-S2AE equivalent, key selection criteria include its 80 MHz high-speed read capability, hardware RY/BY# status reporting via SO during AAI mode, industrial-grade reliability (100,000 program/erase cycles, >100 years data retention), and dual SPI mode (0 and 3) compatibility with diverse host controllers.

Technical Context

The SST25VF040B-80-4I-S2AE implements a four-wire SPI interface (SCK, SI, SO, CE#) with HOLD# and WP# control pins, enabling suspend and write-protection functions without chip deselection. Its SuperFlash® split-gate CMOS architecture provides faster erase times and lower total energy per operation versus conventional flash.

It supports three erase granularities-uniform 4 KByte sectors, 32 KByte overlay blocks, and 64 KByte overlay blocks-and integrates a software-configurable status register with BUSY/WEL/BP/BPL/AAI bits for real-time operation monitoring and flexible block protection. Hardware end-of-write detection reconfigures SO as RY/BY# during AAI programming upon EBSY command (70H).

Key Specifications

Pinout & Package

Package: 8-lead SOIC (200 mils), RoHS-compliant, surface-mountable with standard reflow profile.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SST25VF040B-80-4I-S2AE, W25Q40EW offers higher bandwidth but adds complexity and voltage flexibility not needed in fixed 3.3 V designs, while MX25L4006E matches core functionality but omits AAI acceleration and hardware status reporting - making SST25VF040B-80-4I-S2AE optimal for deterministic, low-overhead firmware updates in resource-constrained industrial hosts.

Availability

SST25VF040B-80-4I-S2AE is available at Aetrix Electronics and suitable for industrial PLC firmware storage, medical device boot code, automotive infotainment UI assets, and smart energy meter firmware requiring stable component supply, long-lifecycle assurance, and RoHS-compliant sourcing.

Supply support for SST25VF040B-80-4I-S2AE 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, FPGA, and memory solutions, with deep expertise in embedded control and secure connectivity.

The SST25VF040B-80-4I-S2AE belongs to Microchip's legacy SST serial flash product line, designed specifically for cost-sensitive, high-reliability embedded applications where deterministic timing, low power, and industrial-grade endurance are mandatory.

FAQ

What is the maximum clock frequency supported by SST25VF040B-80-4I-S2AE for high-speed read operations?

The SST25VF040B-80-4I-S2AE 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 (page 11) and distinguishes it from the -50 variant (50 MHz) and -33 variant (33 MHz). The 80 MHz rating applies specifically to the SST25VF040B-80-4I-S2AE part number and enables sustained read throughput of approximately 10 MB/s in continuous mode.

Does SST25VF040B-80-4I-S2AE support Auto Address Increment (AAI) programming, and how does it improve efficiency?

Yes, SST25VF040B-80-4I-S2AE fully supports Auto Address Increment (AAI) programming using the ADH (1010 1101b) command. As documented on page 12 of DS25051A, AAI eliminates the need to resend the address for each subsequent word, reducing instruction overhead and total programming time - especially valuable during full-image firmware updates. Each AAI cycle programs two bytes at sequential addresses, and hardware RY/BY# status on SO further removes polling latency.

What is the purpose of the HOLD# pin on SST25VF040B-80-4I-S2AE, and how is it used in practice?

The HOLD# pin on SST25VF040B-80-4I-S2AE suspends an ongoing SPI transaction without deselecting the device or resetting internal state, as defined in Figure 4 and page 5 of DS25051A. In practice, this allows a host microcontroller to pause flash access mid-sequence (e.g., during a multi-byte read) to service a higher-priority interrupt, then resume seamlessly - preserving clock alignment and avoiding re-initialization delays. HOLD# requires CE# to remain low and synchronizes with SCK idle state transitions.

How does write protection work on SST25VF040B-80-4I-S2AE, and what are the roles of WP# and the status register BP bits?

SST25VF040B-80-4I-S2AE implements dual-layer write protection: hardware-level via the WP# pin (enabling BPL bit lock-down) and software-level via BP3–BP0 bits in the status register (page 8, Table 4). When WP# is low, the BPL bit becomes read-only, preventing modification of BP bits. BP bits define protected memory regions - e.g., BP3–BP0 = 0001 protects the upper 1/8 (0x70000–0x7FFFF). This enables secure bootloader partitioning where critical code remains immutable during application updates.

Is SST25VF040B-80-4I-S2AE compatible with both SPI Mode 0 and Mode 3, and why does that matter?

Yes, SST25VF040B-80-4I-S2AE explicitly supports both SPI Mode 0 (CPOL=0, CPHA=0) and Mode 3 (CPOL=1, CPHA=1), as stated on page 5 of DS25051A. This dual-mode compatibility ensures interoperability with a broad range of microcontroller SPI peripherals - including legacy and newer MCUs - without requiring hardware redesign or firmware abstraction layers. It eliminates a common integration risk when migrating between silicon platforms or sourcing alternate controllers.