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Microchip Technology SST39LF040-55-4I-WHE
- Part No.:
- SST39LF040-55-4I-WHE
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.488", 12.40mm Width)
- Datasheet:
-
SST39LF040-55-4I-WHE.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
Inventory:1,212
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Product details
Overview
SST39LF040-55-4I-WHE from Microchip Technology (formerly Silicon Storage Technology) is a 4 Mbit (512K × 8) CMOS Multi-Purpose Flash memory IC with 3.0–3.6 V single-supply operation, 55 ns read access time, and JEDEC-standard x8 parallel interface. It features uniform 4 KByte sector erase, 100,000 program/erase cycles endurance, and >100 years data retention - deployed in embedded firmware storage for industrial controllers and legacy BIOS modules.
For engineers reviewing the SST39LF040-55-4I-WHE datasheet, SST39LF040-55-4I-WHE pinout, SST39LF040-55-4I-WHE application, or SST39LF040-55-4I-WHE equivalent, key selection criteria include its 32-pin PLCC package, 55 ns read timing at 3.3 V, hardware/software write protection, and compatibility with standard 8-bit microprocessor buses requiring nonvolatile code storage with sector-level update capability.
Technical Context
The SST39LF040-55-4I-WHE implements SuperFlash technology with split-gate cells and thick-oxide tunneling injectors, enabling fixed erase/program times independent of cycle count. Its command-set architecture uses six-byte software sequences for chip/sector erase and three-byte sequences for byte-program, all compliant with JEDEC-standard flash pinouts and protocols.
It operates across 0°C to +70°C (Commercial grade), supports latched address/data bus timing, and integrates dual write-protection mechanisms: hardware-based (VDD power-up detection, noise filtering) and software-based (JEDEC-approved Software Data Protection). Toggle Bit (DQ6) and Data# Polling (DQ7) provide deterministic end-of-write detection without external polling overhead.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (512K × 8) - provides sufficient space for boot code, configuration tables, and firmware patches in resource-constrained 8-bit systems. |
| Read Access Time | 55 ns - enables direct execution from flash (XIP) on microcontrollers with ≤18 MHz bus clocks without wait states. |
| Supply Voltage | 3.0–3.6 V - compatible with standard 3.3 V logic rails and eliminates need for separate VPP programming voltage. |
| Endurance | 100,000 program/erase cycles - supports field firmware updates over full product lifecycle in industrial equipment. |
| Data Retention | >100 years - ensures long-term reliability in unpowered storage applications such as calibration data or security keys. |
| Sector Size | Uniform 4 KByte sectors - allows granular firmware partitioning (e.g., bootloader, application, parameter storage) without erasing entire device. |
| Write Detection | Toggle Bit (DQ6) and Data# Polling (DQ7) - enables host software to poll status without dedicated interrupt lines or timer-based delays. |
Pinout & Package
Package: 32-lead PLCC (Plastic Leaded Chip Carrier), RoHS-compliant, surface-mountable with standard reflow profile (260°C/10 s).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A18 | Address Inputs | A0–A15 used for byte addressing; A16–A18 select sector/block during erase - A18 active for SST39LF040 confirming 512K × 8 organization. |
| DQ0–DQ7 | Data Input/Output | Bi-directional 8-bit data bus; DQ6 = Toggle Bit, DQ7 = Data# Polling - both used for write-status feedback without additional control signals. |
| CE# | Chip Enable | Active-low chip select; must be low for read/write operations - enables multi-device bus decoding in systems with multiple memory devices. |
| OE# | Output Enable | Active-low output gate; controls tri-state buffer - allows shared data bus with other peripherals without contention. |
| WE# | Write Enable | Active-low write strobe; initiates byte-program or command sequence - synchronized with CE# for JEDEC-compliant timing. |
| VDD | Power Supply | +3.0 to +3.6 V supply - powers core logic and charge pump; no external VPP required due to on-chip high-voltage generation. |
| VSS | Ground | Reference ground for all I/O and internal circuitry - requires low-impedance connection to minimize noise during erase/program pulses. |
| NC | No Connection | Pins 12, 16, 24, 31 are unconnected - must remain floating; not usable as GPIO or alternate functions. |
Key Features
| Feature | Design Value |
|---|---|
| SuperFlash® Technology | Split-gate cell architecture delivers fixed 18 ms sector-erase and 70 ms chip-erase times regardless of accumulated wear - eliminates software de-rating and simplifies timing-critical firmware design. |
| Software Data Protection | JEDEC-standard 3-byte (program) and 6-byte (erase) command sequences prevent accidental writes during power transitions - mandatory for robust field-upgrade implementations. |
| Hardware Write Inhibit | VDD power-up/down detection and sub-5 ns noise immunity block spurious WE#/CE# pulses - ensures reliable boot from flash even under noisy power conditions. |
| Low Standby Current | 1 µA typical - reduces system quiescent power in battery-backed or energy-sensitive applications like remote sensors and metering devices. |
| CMOS I/O Compatibility | Full 3.3 V TTL-compatible input thresholds (VIH = 0.7×VDD, VIL = 0.8 V) and output drive (VOH = VDD−0.2 V, VOL = 0.2 V) - interfaces directly with standard microcontrollers without level shifters. |
Applications
| Firmware Storage in Industrial PLCs | Legacy BIOS Code Storage |
|---|---|
Use Scenario: Storing ladder logic firmware and I/O configuration tables in programmable logic controllers operating in factory-floor environments with wide temperature swings and electrical noise. IC Role / Device Role / Timing Role: Nonvolatile code storage with sector-erase capability enabling field updates of control algorithms without full reflash downtime. Use Value: 100,000-cycle endurance and >100-year data retention ensure firmware integrity over 15+ year equipment lifespans without maintenance. |
Use Scenario: Holding POST routines and hardware initialization code in legacy PC motherboards where BIOS size remains under 512 KB and parallel interface is retained for cost reasons. IC Role / Device Role / Timing Role: XIP-capable boot memory with 55 ns access time - meets timing budgets for 80486/Pentium-class processors running at ≤18 MHz. Use Value: JEDEC-standard pinout and command set allow drop-in replacement of older 27C040 EPROMs without PCB redesign. |
| Embedded Telematics Module Configuration | Point-of-Sale Terminal Parameter Storage |
Use Scenario: Storing GPS calibration offsets, cellular modem profiles, and vehicle-specific CAN message maps in automotive telematics units subject to thermal cycling and vibration. IC Role / Device Role / Timing Role: Sector-erasable nonvolatile memory supporting secure over-the-air (OTA) firmware patches via isolated sector updates. Use Value: Hardware write inhibit prevents corruption during vehicle ignition transients; 3.3 V operation aligns with main system rail. |
Use Scenario: Maintaining tax rate tables, receipt formatting templates, and user-access permissions in retail POS terminals deployed globally with varying regulatory requirements. IC Role / Device Role / Timing Role: Field-updatable configuration store accessed via 8-bit microcontroller bus during terminal boot and operator setup. Use Value: Uniform 4 KByte sectors enable country-specific parameter sets to be updated independently, minimizing OTA payload size and transmission time. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar parallel-interface flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29LV040B-55EC | 4 Mbit (512K × 8), 55 ns read, 3.0–3.6 V, but uses AMD-style command set (not JEDEC); lacks Toggle Bit status signaling. | Requires modified driver firmware for erase/program; no hardware-assisted write completion detection - increases CPU polling load. | Select only if existing AMD-compatible firmware stack is in place and JEDEC compliance is not required. |
| MX29LV040CTT-55G | 4 Mbit (512K × 8), 55 ns read, 3.0–3.6 V, JEDEC-compatible, but rated for Industrial (-40°C to +85°C) temperature range. | Higher temperature rating suits extended-environment deployments; identical pinout and command set to SST39LF040-55-4I-WHE. | Preferred for new designs targeting industrial temperature operation; otherwise functionally interchangeable in commercial-grade systems. |
Compared with AM29LV040B-55EC and MX29LV040CTT-55G, the SST39LF040-55-4I-WHE offers JEDEC-standard command compatibility and integrated Toggle Bit/Data# Polling - reducing firmware complexity and improving real-time write verification accuracy in commercial-temperature embedded systems.
Availability
SST39LF040-55-4I-WHE is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy BIOS code retention, and embedded telematics configuration requiring stable component supply and long-lifecycle support.
Supply support for SST39LF040-55-4I-WHE 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 acquired Silicon Storage Technology (SST) in 2016 and maintains the SuperFlash® portfolio for cost-sensitive, high-reliability embedded memory applications.
The SST39LF040-55-4I-WHE belongs to the SST39LF/VF series of Multi-Purpose Flash devices designed specifically for 8-bit microprocessor-based systems needing fast, sector-erasable nonvolatile storage with minimal external components and legacy bus compatibility.
FAQ
What is the maximum operating temperature range for the SST39LF040-55-4I-WHE?
The SST39LF040-55-4I-WHE is specified for Commercial temperature range: 0°C to +70°C. It is not rated for Industrial (-40°C to +85°C) operation - that specification applies to the SST39VF040 variant. The 'I' suffix in SST39LF040-55-4I-WHE denotes Industrial-grade packaging (moisture sensitivity level, lead finish), not extended temperature operation. Always verify ambient thermal design against this 0°C to +70°C limit when deploying SST39LF040-55-4I-WHE.
Does the SST39LF040-55-4I-WHE require an external VPP voltage for programming?
No, the SST39LF040-55-4I-WHE does not require an external VPP voltage. It uses on-chip charge pump circuitry to generate the high voltage needed for programming and erasing, operating solely from the 3.0–3.6 V VDD supply. This eliminates the need for external high-voltage generators or complex power sequencing - a key advantage over older EPROM and EEPROM technologies. All write operations for SST39LF040-55-4I-WHE are fully supported within its single VDD range.
How many address pins does the SST39LF040-55-4I-WHE use, and why does the datasheet reference A18?
The SST39LF040-55-4I-WHE uses 19 address pins (A0–A18) to support its 512K × 8 organization (219 = 524,288 addresses). A0–A15 select individual bytes; A16–A18 are used during sector and chip erase commands to select target sectors or blocks. The presence of A18 confirms the 4 Mbit density - SST39LF010 uses A16, SST39LF020 uses A17, and SST39LF040 uses A18 per the datasheet's AMS definition. Pin A18 is active and functional on SST39LF040-55-4I-WHE.
Can the SST39LF040-55-4I-WHE be used as a direct replacement for the SST39LF020-55-4C-WHE?
No, the SST39LF040-55-4I-WHE is not a direct replacement for the SST39LF020-55-4C-WHE due to differences in memory size (4 Mbit vs. 2 Mbit), address pin usage (A18 required vs. A17), and temperature grading (Commercial vs. Industrial packaging). While both share identical command sets and pinouts, the larger address space of SST39LF040-55-4I-WHE may cause unintended memory accesses if the host system does not drive A18 correctly. Firmware and hardware validation are required before substitution.
What is the purpose of the NC pins on the SST39LF040-55-4I-WHE PLCC package?
The NC (No Connection) pins on the SST39LF040-55-4I-WHE - specifically pins 12, 16, 24, and 31 in the 32-lead PLCC package - are internally unconnected and must remain electrically floating. They serve no functional role in operation, timing, or protection. Connecting them to VDD, VSS, or signal lines may cause unpredictable behavior or damage. The SST39LF040-55-4I-WHE datasheet explicitly defines these as NC; no alternate functions or future-use provisions are assigned to them.
SST39LF040-55-4I-WHE Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- SST39 MPF™
- Package/Case:
- 32-TFSOP (0.488", 12.40mm Width)
- Packaging:
- Tray
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 4Mbit
- Memory Organization:
- 512K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 20µs
- Access Time:
- 55 ns
- Voltage - Supply:
- 3V ~ 3.6V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-TSOP
SST39LF040-55-4I-WHE FAQ
1.How can I place an order for SST39LF040-55-4I-WHE through Aetrix?
Please submit a Request for Quotation (RFQ) for SST39LF040-55-4I-WHE on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for SST39LF040-55-4I-WHE reliable?
The price and inventory of SST39LF040-55-4I-WHE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SST39LF040-55-4I-WHE is usually 5 days.
3.What payment methods are accepted for SST39LF040-55-4I-WHE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SST39LF040-55-4I-WHE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SST39LF040-55-4I-WHE?
SST39LF040-55-4I-WHE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SST39LF040-55-4I-WHE order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for SST39LF040-55-4I-WHE?
For technical support, including SST39LF040-55-4I-WHE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SST39LF040-55-4I-WHE requirements.
6.How does Aetrix verify that SST39LF040-55-4I-WHE is sourced from the original manufacturer or authorized distributors?
All SST39LF040-55-4I-WHE products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that SST39LF040-55-4I-WHE meets industry standards.
7.What is the process for return or replacement of SST39LF040-55-4I-WHE?
All SST39LF040-55-4I-WHE units undergo pre-shipment inspection (PSI). If there is an issue with SST39LF040-55-4I-WHE, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The SST39LF040-55-4I-WHE part is unused and in its original packaging.
Return procedure for SST39LF040-55-4I-WHE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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