SST39SF040-45-4C-WHE-T Microchip Integrated Circuit (Small Outline Packages) In Stock
SST39SF040-45-4C-WHE-T is a 4 Mbit (512 KB) multi-purpose SuperFlash memory from Microchip, operating from a 4.5 V to 5.5 V supply with a 45 ns access time. It features sector and block erase with 100,000 erase cycles endurance and is available in a small outline package for embedded code storage applications.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 32
- Lifecycle
- ACTIVE
- Datasheet
- SST39SF040-45-4C-WHE-T Datasheet PDF
- Category
- Integrated Circuit
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 4 Mbit (512 KB) SuperFlash memory density for embedded firmware and code storage
- 45 ns read access time enabling fast program execution in parallel bus architectures
- 4.5 V to 5.5 V supply voltage compatible with 5 V TTL and CMOS system buses
- Sector erase (2 KB) and block erase (64 KB) for flexible in-system programming
- 100,000 minimum erase cycles per sector ensuring reliable field-update capability
- Software data protection (SDP) and hardware reset for secure write control
Applications
SST39SF040-45-4C-WHE-T is used for firmware storage in embedded systems such as industrial PLCs, CNC controllers, and legacy BIOS platforms that use parallel NOR flash on a 5 V bus. Its 45 ns access time allows zero-wait-state operation with many 8-bit and 16-bit microprocessors, making it a drop-in code storage solution for real-time control applications. The sector erase granularity and SDP feature support in-system firmware updates while protecting against accidental writes in production environments.
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
Alternate & Equivalent Parts
No known alternates. Submit an RFQ and our team can suggest alternatives.
Frequently Asked Questions
What is the read access time of SST39SF040-45-4C-WHE-T, and does it support zero-wait-state operation with common 8-bit microcontrollers?
SST39SF040-45-4C-WHE-T has a 45 ns read access time, which matches or exceeds the bus cycle times of many 8-bit microcontrollers running at up to 20 MHz, enabling zero-wait-state code execution without inserting additional bus hold cycles. For processors such as the Intel 8051 or Zilog Z80 family clocked below 22 MHz, the 45 ns access time ensures the data is valid well before the read strobe de-asserts.
How many erase cycles does SST39SF040-45-4C-WHE-T guarantee per sector, and what does this mean for in-field firmware update frequency?
SST39SF040-45-4C-WHE-T is rated for a minimum of 100,000 erase/write cycles per 2 KB sector, which translates to over 100,000 firmware update events per sector before potential wear-out. For industrial equipment with annual firmware updates, this exceeds a 100-year service life per sector, and even for monthly field updates the 8,000-year equivalent lifespan means wear is not a practical concern in most embedded applications.
When should SST39SF040-45-4C-WHE-T be selected over a serial SPI flash for a legacy parallel-bus embedded design?
SST39SF040-45-4C-WHE-T is the right choice when the host processor uses a multiplexed or dedicated parallel address/data bus that cannot be easily converted to SPI without adding a bridge IC or CPLD. Legacy 8-bit and 16-bit CPUs with memory-mapped I/O benefit from the 45 ns parallel access latency, which is significantly lower than SPI flash read latencies of 100 ns to 200 ns at equivalent clock speeds, while eliminating the firmware overhead of a serial flash driver.
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