SST39SF040-45-4I-WHE-T Microchip Integrated Circuit (Small Outline Packages) In Stock
Microchip SST39SF040 is a 4 Mbit (512 KB) parallel NOR Flash memory with 45 ns access time and 5 V supply. It supports sector and full-chip erase with a 32-pin TSOP package, suitable for embedded firmware storage and BIOS applications.
- Manufacturer
- Microchip
- Package
- Small Outline Packages
- Pin Count
- 32
- Lifecycle
- ACTIVE
- Datasheet
- SST39SF040-45-4I-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) parallel NOR Flash storage
- Fast 45 ns read access time
- 5 V single-supply operation
- Sector erase (4 KB) and chip erase support
- 100,000 erase/write cycles endurance
- 32-pin TSOP package for compact PCB integration
- Data retention exceeding 100 years
Applications
The SST39SF040 is widely used for BIOS firmware storage in embedded computing systems, industrial controllers, and legacy PC motherboards requiring reliable parallel NOR Flash. Its 45 ns fast access time enables direct XIP (execute in place) operation in 5 V processor systems. The 32-pin TSOP package supports high-density PCB layouts in networking and communications equipment.
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
How fast can the SST39SF040 deliver data, and does it support execute-in-place operation?
The SST39SF040 has a maximum read access time of 45 ns, which is fast enough for execute-in-place (XIP) use with many 5 V embedded processors. It provides 4 Mbit of storage across a parallel bus interface, making firmware execution directly from Flash feasible without a separate RAM buffer.
What erase granularity does the SST39SF040 offer for firmware update workflows?
The SST39SF040 supports 4 KB sector erase as well as full 512 KB chip erase. Sector-level erase allows targeted firmware updates in 4 KB increments, reducing write cycles and improving endurance up to 100,000 erase/write cycles per sector, which is important for field-updatable embedded systems.
When would the SST39SF040 be preferred over a serial SPI Flash of the same density?
For legacy 5 V parallel bus systems such as older microprocessor designs or BIOS sockets, the SST39SF040 is preferred because it delivers 45 ns random access without the latency overhead of serial SPI protocol. Its 32-pin TSOP footprint fits standard BIOS socket adapters, avoiding redesign for parallel-bus architectures still in production.
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