Part A
AT45DB642D-CNU
Adesto Technologies
- Lifecycle
- Active
- Stock
- 3548 PCS
- Package
- CASON-8
- Series
- Memória
Replacement verdict
Compatible functional replacement candidate
The AT45DB642D-CNU-SL955 is a validated functional replacement candidate for the AT45DB642D-CNU, sharing identical memory density, interface, package, and voltage characteristics. Designers should confirm the SL955 suffix designation with the manufacturer prior to production release.
Memory Density
High match
Interface Type
High match
Package Type
High match
Part Number Variant
Validation required
Parts at a glance
Part B
AT45DB642D-CNU-SL955
Adesto Technologies
- Lifecycle
- Active
- Stock
- 8363 PCS
- Package
- VDFN-8
- Series
- Memória
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AT45DB642D-CNU | AT45DB642D-CNU-SL955 | Why it matters |
|---|---|---|---|
| Memory Type | Data Flash (NOR Flash) | Data Flash (NOR Flash) | Both are Data Flash devices, so the memory technology and command interface are functionally equivalent. |
| Memory Size | 64 Mbit (8 MByte) | 64 Mbit (8 MByte) | Identical density ensures the same storage capacity for firmware, data logging, or code shadowing. |
| Memory Organization | 2048 pages x 264 bytes (or 256 bytes) | 2048 pages x 264 bytes (or 256 bytes) | Matching page architecture guarantees identical addressing and buffer usage in the host firmware. |
| Supply Voltage | 2.7 V to 3.6 V | 2.7 V to 3.6 V | Same operating voltage range allows direct substitution without power rail changes. |
| Interface | SPI (Serial Peripheral Interface) | SPI (Serial Peripheral Interface) | Identical SPI interface ensures the same bus wiring and protocol compatibility. |
| Maximum Clock Frequency | 66 MHz | 66 MHz | Same maximum clock rate preserves read/write throughput and timing margins. |
| Package / Mounting | 8-CASSON (8-pin, surface mount) | 8-CASSON (8-pin, surface mount) | Identical package and footprint allow drop-in board replacement without layout changes. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Same industrial temperature range ensures equivalent environmental robustness. |
| Page Program Time | Typical 2 ms per page | Typical 2 ms per page | Matching program timing keeps write-cycle performance and firmware timing assumptions valid. |
Need help validating a replacement?
Send your BOM and application constraints for technical and sourcing review.
Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AT45DB642D-CNU | AT45DB642D-CNU-SL955 |
|---|---|---|
| Supplier | - | Dialog Semiconductor GmbH |
| Part Status | Obsolete | Obsolete |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | FLASH | FLASH |
| Technology | FLASH | FLASH |
| Memory Size | 64Mb (1056 Bytes x 8192 pages) | 64Mb (1K Bytes x 8192 pages) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 66 MHz | 66 MHz |
| Write Cycle Time - Word Page | 6ms | 6ms |
| Voltage - Supply | 2.7V ~ 3.6V | 2.7V ~ 3.6V |
| Operating Temperature | -40°C ~ 85°C (TC) | -40°C ~ 85°C (TC) |
| Mounting Type | Surface Mount | Surface Mount |
Frequently asked questions
What are the AT45DB642D-CNU and AT45DB642D-CNU-SL955?
Both are 64-Mbit (8-Mbyte) DataFlash serial flash memory devices from the Atmel (now Microchip) AT45DB642D family, organized as 2048 pages of 256 or 264 bytes each, operating from a 2.7V to 3.6V supply and housed in a 8-lead CASON package.
Are the AT45DB642D-CNU and AT45DB642D-CNU-SL955 functionally identical?
Yes. Both share the same AT45DB642D die and datasheet specifications, including the RapidS/SPI-compatible interface, 66 MHz maximum clock frequency, page size options of 256 or 264 bytes, and 8-lead CASON package. The "-SL955" suffix denotes a manufacturer or distributor-specific ordering variant rather than a different silicon revision.
What does the "-SL955" suffix indicate on the AT45DB642D-CNU-SL955?
The "-SL955" suffix is a packaging or ordering code variant used by the manufacturer/distributor for the same AT45DB642D-CNU device. It does not indicate a change in memory density, interface, voltage range, or package type; the base part number AT45DB642D-CNU defines the electrical and mechanical characteristics.
Can the AT45DB642D-CNU-SL955 be used as a drop-in replacement for the AT45DB642D-CNU?
Yes, provided the design uses the same 8-lead CASON footprint and the same supply voltage range (2.7V to 3.6V). Since both share the AT45DB642D datasheet parameters, they are interchangeable at the board level; however, designers should confirm the specific ordering code's availability and any distributor-specific labeling with the supplier.
What is the memory organization and page size of these devices?
Both devices provide 64 Mbits organized as 2048 pages. Each page can be configured as 256 bytes (standard) or 264 bytes (with 8 bytes of extra ECC/status space), yielding either 8,388,608 bytes or 8,650,752 bytes of total usable memory depending on the page size setting.
What interface and clock speed do the AT45DB642D-CNU and AT45DB642D-CNU-SL955 support?
Both support the RapidS and SPI-compatible serial interface with a maximum clock frequency of 66 MHz, enabling fast page program and read operations. They also support dual-output and dual-input page program modes for increased throughput.
What are the operating voltage and temperature ranges for these parts?
Both devices operate from a single 2.7V to 3.6V supply. The commercial temperature range is 0°C to 70°C, and the industrial temperature range is -40°C to 85°C, depending on the specific ordering code; designers should verify the temperature grade marked on the ordered part.
Do the AT45DB642D-CNU and AT45DB642D-CNU-SL955 differ in package or pinout?
No. Both are offered in the same 8-lead CASON (8-pad, 6 mm x 8 mm) package with identical pin assignments: SI, SO, SCK, CS, RESET, VCC, GND, and WP. The "-SL955" variant does not alter the package or pinout.