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Microchip Technology SST39SF040-45-4I-WHE
- Part No.:
- SST39SF040-45-4I-WHE
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 32-TFSOP (0.488", 12.40mm Width)
- Datasheet:
-
SST39SF040-45-4I-WHE.pdf
- Description:
- IC FLASH 4MBIT PARALLEL 32TSOP
- Quantity:
- Payment:
- Shipping:
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Product details
Overview
SST39SF040-45-4I-WHE from Microchip Technology is a 4 Mbit (512K × 8) CMOS Multi-Purpose Flash memory IC with single 4.5–5.5V supply operation, 55 ns read access time, and JEDEC-standard x8 parallel interface. It features uniform 4 KByte sector erase, 100,000 program/erase endurance, and >100 years data retention - deployed in embedded firmware storage for industrial controllers and legacy BIOS modules.
For engineers reviewing the SST39SF040-45-4I-WHE datasheet, SST39SF040-45-4I-WHE pinout, SST39SF040-45-4I-WHE application, or SST39SF040-45-4I-WHE equivalent, key selection criteria include 32-pin PLCC package compatibility, TTL I/O voltage levels, sector-erase timing (18 ms typical), hardware/software write protection, and 55 ns read performance under industrial temperature range (–40°C to +85°C).
Technical Context
This device implements SST's proprietary SuperFlash technology with split-gate cell architecture and thick-oxide tunneling injector, enabling fixed erase/program times independent of cycle count - eliminating software de-rating over lifetime. It operates exclusively in parallel x8 mode with address latching, data latching, and standard JEDEC command sets (e.g., 6-byte sector-erase sequence).
Write operations require 4.5–5.5V VDD only - no external VPP - and support two end-of-write detection methods: Data# Polling (DQ7) and Toggle Bit (DQ6). All control signals (CE#, OE#, WE#) are active-low and fully TTL-compatible, with tri-state outputs when CE# or OE# is high.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 4 Mbit (512K × 8) - supports full firmware image storage for 8-bit microcontrollers without bank switching. |
| Read Access Time | 55 ns - enables direct execution from flash (XIP) in systems with ≤18 MHz bus clocks. |
| Supply Voltage | 4.5–5.5V - compatible with legacy 5V logic rails; no auxiliary voltage required. |
| Endurance | 100,000 program/erase cycles - sufficient for field-upgradable firmware with annual updates over 10+ years. |
| Data Retention | >100 years at 25°C - ensures long-term reliability in unpowered storage applications. |
| Sector Size | Uniform 4 KByte sectors - simplifies partitioning for bootloader, application, and configuration sections. |
| Operating Temp | –40°C to +85°C - qualified for industrial-grade embedded systems including PLCs and motor drives. |
Pinout & Package
Package: 32-lead PLCC (Plastic Leaded Chip Carrier), body size 13.97 mm × 13.97 mm, lead pitch 1.27 mm. RoHS compliant, surface-mountable with standard reflow profile.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A17 | Address Inputs | 18-bit address bus; A17 is MSB for 512K-word addressing (SST39SF040-specific). |
| DQ0–DQ7 | Data Input/Output | 8-bit bidirectional data bus; latched internally during writes; tri-stated when CE# or OE# high. |
| CE# | Chip Enable | Active-low chip select; device enters standby (30 µA) when high. |
| OE# | Output Enable | Active-low output gate; controls data bus drive without affecting internal state. |
| WE# | Write Enable | Active-low write control; initiates byte-program, sector-erase, or chip-erase on rising edge. |
| VDD | Power Supply | +4.5V to +5.5V supply; powers all logic and flash array; no separate VPP needed. |
| VSS | Ground | Reference ground for all signals and internal circuitry. |
| NC | No Connection | Pins 16 and 31 are unconnected; must be left floating or tied to ground per layout guidelines. |
Key Features
| Feature | Design Value |
|---|---|
| SuperFlash® Technology | Split-gate cell with thick-oxide injector enables fixed 18 ms sector-erase time across full lifecycle - no timing degradation with wear. |
| Hardware Write Protection | Glitch immunity (<5 ns pulses rejected), VDD power-up/down detection (<2.5V inhibits writes), and CE#/OE#/WE# control lockout prevent accidental erasure. |
| Software Data Protection | JEDEC-compliant 3-byte (program) and 6-byte (erase) command sequences - shipped enabled - eliminate need for external lock bits or security fuses. |
| End-of-Write Detection | Dual-mode status reporting via DQ7 (Data# Polling) and DQ6 (Toggle Bit) - allows host CPU to multitask during 20 µs byte-program or 70 ms chip-erase. |
| TTL-Compatible Interface | Full 5V-tolerant inputs and outputs with VIH = 2.0V min, VOL = 0.4V max at 2.1 mA - interoperable with legacy 8051, Z80, and 68K-based systems. |
Applications
| Industrial PLC Firmware Storage | Legacy PC BIOS Memory |
|---|---|
Use Scenario: Storing ladder logic programs 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 direct bus interface; executes XIP during boot; sector-erase enables modular firmware updates without full reflash. Use Value: 55 ns read access ensures deterministic scan-cycle timing; 100,000-cycle endurance supports 5+ years of field updates; industrial temp rating eliminates external thermal management. | Use Scenario: Holding BIOS initialization code and hardware configuration data in desktop motherboards from late 1990s to early 2000s, where space and cost constrained upgrade paths. IC Role / Device Role / Timing Role: Primary boot ROM replacement for EPROMs; connected directly to ISA/LPC bus with no glue logic. Use Value: Pin-compatible drop-in for 27C040 EPROMs; 4.5–5.5V operation matches legacy 5V rail; 32-pin PLCC fits existing sockets; JEDEC command set ensures BIOS ROM routines require zero modification. |
| Medical Device Bootloader | Point-of-Sale Terminal Configuration |
Use Scenario: Secure storage of bootloader code and calibration constants in FDA-cleared diagnostic instruments requiring traceable firmware revision control and field patching. IC Role / Device Role / Timing Role: Isolated boot-stage memory; accessed only during power-on reset; write-protected except during authenticated update sequences. Use Value: Software Data Protection prevents unauthorized writes; >100-year data retention meets medical device shelf-life requirements; sector-erase allows safe patching of bootloader without corrupting application partition. | Use Scenario: Storing localized language packs, tax tables, and peripheral driver configurations in retail POS terminals deployed globally across diverse power grids. IC Role / Device Role / Timing Role: Field-updatable configuration memory mapped into microcontroller address space; updated via serial port during maintenance windows. Use Value: Uniform 4 KByte sectors enable atomic updates of regional settings; 30 µA standby current extends battery backup runtime; industrial temp rating ensures reliability in unairconditioned storefronts. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AM29LV040B-70EC | 4 Mbit (512K × 8), 70 ns access, 3.0V core + 5V I/O, 12V VPP required for programming | Requires dual-voltage design and external charge pump; not pin-compatible due to different VPP pin assignment | Select only if system already supports 3.3V/5V mixed supply and needs lower active power; not suitable for direct SST39SF040-45-4I-WHE replacement. |
| MX29LV040CTTC-70G | 4 Mbit (512K × 8), 70 ns access, 3.0V-only operation, no 5V tolerance | Not TTL-compatible; requires level-shifting for 5V buses; lacks hardware write inhibit on power ramp | Use only in new 3.3V designs; incompatible with legacy 5V systems without interface redesign. |
Compared with AM29LV040B-70EC and MX29LV040CTTC-70G, the SST39SF040-45-4I-WHE delivers true 5V single-supply operation with no VPP, guaranteed 55 ns timing, and robust hardware write protection - making it the only viable drop-in solution for maintaining legacy 5V embedded systems without board redesign.
Availability
SST39SF040-45-4I-WHE is available at Aetrix Electronics and suitable for industrial PLC firmware storage, legacy PC BIOS replacement, medical device bootloaders, and point-of-sale terminal configuration requiring stable component supply and long-lifecycle support.
Supply support for SST39SF040-45-4I-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 is a global semiconductor company specializing in microcontrollers, analog devices, and memory solutions, with emphasis on embedded control and long-lifecycle product support.
The SST39SF040-45-4I-WHE belongs to Microchip's legacy SuperFlash parallel NOR flash product line, designed specifically for cost-sensitive, 5V-based embedded systems requiring field-upgradable nonvolatile storage without complex voltage management.
FAQ
What is the maximum operating frequency supported by SST39SF040-45-4I-WHE?
The SST39SF040-45-4I-WHE does not operate at a clock frequency - it is an asynchronous parallel flash memory. Its performance is defined by access timing parameters: 55 ns read cycle time (TRC) and 20 µs byte-program time (TBP). These values assume proper setup/hold timing for CE#, OE#, and WE# signals per Table 11 and Table 12 in the datasheet. System bus speed is limited by these static timings, not a clock domain.
Does SST39SF040-45-4I-WHE require an external VPP voltage for programming?
No, the SST39SF040-45-4I-WHE does not require an external VPP voltage. It performs all program and erase operations using only the 4.5–5.5V VDD supply. Internal charge pump circuitry generates the high voltage needed for Fowler-Nordheim tunneling, eliminating the need for external high-voltage circuitry or dedicated VPP pins - a key advantage over older EPROM and some competing flash devices.
How is sector erase initiated on SST39SF040-45-4I-WHE?
Sector erase on SST39SF040-45-4I-WHE is initiated via a six-byte software command sequence: 5555H/AAH → 2AAAH/55H → 5555H/80H → 5555H/AAH → 2AAAH/55H → SAX/30H, where SAX is the 18-bit sector address (A17–A12). The final 30H command and sector address are latched on the sixth WE# pulse. Erase completes in 18 ms (typical), with completion detectable via DQ6 toggle or DQ7 polling.
Is SST39SF040-45-4I-WHE pin-compatible with standard 27C040 EPROMs?
Yes, the SST39SF040-45-4I-WHE is functionally and pin-compatible with 27C040 EPROMs in 32-pin PLCC packages. It uses identical pinout (A0–A17, DQ0–DQ7, CE#, OE#, WE#, VDD, VSS), same 5V supply, and JEDEC-standard command protocol - enabling direct socket replacement without PCB changes. However, unlike EPROMs, it requires no UV erasure and supports in-system electrical erase/program.
What is the purpose of the NC pins on SST39SF040-45-4I-WHE?
The SST39SF040-45-4I-WHE has two NC (No Connect) pins: Pin 16 and Pin 31 in the 32-lead PLCC package. These pins are internally unconnected and must remain unbonded. Per Microchip's layout guidance, they may be left floating or tied to ground for mechanical stability - but must never be driven or used as signal lines, as doing so risks latch-up or undefined behavior.
SST39SF040-45-4I-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:
- 45 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 32-TSOP
SST39SF040-45-4I-WHE FAQ
1.How can I place an order for SST39SF040-45-4I-WHE through Aetrix?
Please submit a Request for Quotation (RFQ) for SST39SF040-45-4I-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 SST39SF040-45-4I-WHE reliable?
The price and inventory of SST39SF040-45-4I-WHE are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for SST39SF040-45-4I-WHE is usually 5 days.
3.What payment methods are accepted for SST39SF040-45-4I-WHE?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for SST39SF040-45-4I-WHE transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for SST39SF040-45-4I-WHE?
SST39SF040-45-4I-WHE orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your SST39SF040-45-4I-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 SST39SF040-45-4I-WHE?
For technical support, including SST39SF040-45-4I-WHE datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your SST39SF040-45-4I-WHE requirements.
6.How does Aetrix verify that SST39SF040-45-4I-WHE is sourced from the original manufacturer or authorized distributors?
All SST39SF040-45-4I-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 SST39SF040-45-4I-WHE meets industry standards.
7.What is the process for return or replacement of SST39SF040-45-4I-WHE?
All SST39SF040-45-4I-WHE units undergo pre-shipment inspection (PSI). If there is an issue with SST39SF040-45-4I-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 SST39SF040-45-4I-WHE part is unused and in its original packaging.
Return procedure for SST39SF040-45-4I-WHE:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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