Part A
AT25DF081A-SSH-T
Adesto Technologies
- Lifecycle
- Active
- Stock
- 3274 Stückzahl
- Package
- SOIC-8
- Series
- Speicher
Replacement verdict
Compatible functional replacement candidate
The AT25DF041A-SH-B is a functional replacement candidate for the AT25DF081A-SSH-T only when the system design can accommodate the reduced 4-Mbit density and the different package and interface configuration; the 8-Mbit AT25DF081A-SSH-T cannot be directly substituted where full 8-Mbit capacity, dual-I/O operation, or the SOIC-8 wide-body footprint is required.
Memory Density
Not compatible
Package Type
Validation required
Interface / I/O Configuration
Validation required
Supply Voltage Range
High match
Parts at a glance
Part B
AT25DF041A-SH-B
Adesto Technologies
- Lifecycle
- Active
- Stock
- 5305 Stückzahl
- Package
- SOIC-8
- Series
- Speicher
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AT25DF081A-SSH-T | AT25DF041A-SH-B | Why it matters |
|---|---|---|---|
| Memory Density | 8 Mbit (1 MB) | 4 Mbit (512 KB) | Density determines total storage capacity; a smaller density part cannot hold firmware or data sized for the larger device, so they are not directly substitutable without code/data resizing. |
| Memory Organization | 1,024 pages x 256 bytes; 256 sectors x 4 KB | 512 pages x 256 bytes; 128 sectors x 4 KB | Page and sector sizes affect erase/write granularity and driver addressing; matching 256-byte pages and 4 KB sectors simplifies firmware portability between the two parts. |
| Supply Voltage Range | 2.7 V to 3.6 V | 2.7 V to 3.6 V | Identical operating voltage ranges mean the same power rail and level-shifting design can be reused, which is essential for drop-in compatibility. |
| Interface Type | SPI (single/dual output) | SPI (single/dual output) | A matching SPI interface and command set allows the same host controller and driver to communicate with either device without protocol changes. |
| Maximum Clock Frequency | 70 MHz | 70 MHz | Equal maximum clock rates ensure comparable read/write throughput and that timing budgets in the host design remain valid for either part. |
| Package / Mounting | 8-SOIC (0.154", 3.90mm width), surface mount | 8-SOIC (0.154", 3.90mm width), surface mount | Package and footprint compatibility determines whether the part can be placed on the same PCB land pattern; matching SOIC-8 packages support physical interchangeability. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Identical industrial temperature ratings mean both parts suit the same environmental conditions and thermal qualification requirements. |
| Endurance (Program/Erase Cycles) | 100,000 cycles per sector | 100,000 cycles per sector | Matching endurance ratings indicate comparable long-term reliability for frequently rewritten data, supporting equivalent field lifetime expectations. |
| Data Retention | 20 years | 20 years | Equal data retention specifications confirm both devices meet the same non-volatile storage longevity requirements for the application. |
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Full specification comparison
Use manufacturer datasheets as the final authority.
| Specification | AT25DF081A-SSH-T | AT25DF041A-SH-B |
|---|---|---|
| Supplier | - | Dialog Semiconductor GmbH |
| Part Status | Active | Obsolete |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | FLASH | FLASH |
| Technology | FLASH | FLASH |
| Memory Size | 8Mb (256 Bytes x 4096 pages) | 4Mb (512K x 8) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 100 MHz | 70 MHz |
| Write Cycle Time - Word Page | 7µs, 3ms | 7µs, 5ms |
| 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 key differences between the AT25DF081A-SSH-T and the AT25DF041A-SH-B?
The AT25DF081A-SSH-T is an 8-Mbit (1 MByte) SPI serial flash memory, while the AT25DF041A-SH-B is a 4-Mbit (512 KByte) device. Both are part of the Adesto (formerly Atmel) AT25DF series and use the same SPI interface, but they differ in density, package, and ordering suffix. The AT25DF081A-SSH-T is supplied in an 8-lead SOIC (0.150" body) tape-and-reel package, whereas the AT25DF041A-SH-B is supplied in an 8-lead SOIC (0.208" body) package.
Are the AT25DF081A-SSH-T and AT25DF041A-SH-B pin-compatible?
Both devices use the standard 8-lead SOIC serial flash pinout (CS, SO, WP, GND, SI, SCLK, HOLD, VCC), so the pin functions are the same. However, the package body widths differ (0.150" for the AT25DF081A-SSH-T versus 0.208" for the AT25DF041A-SH-B), so PCB land patterns must be verified before substituting one for the other.
Do both devices support the same SPI interface and command set?
Yes. Both the AT25DF081A-SSH-T and AT25DF041A-SH-B support standard SPI modes 0 and 3, with clock frequencies up to 70 MHz for read operations, and share the same command set including Read, Program, Erase, Write Enable/Disable, Read Status Register, and JEDEC ID commands. The primary functional difference is memory density.
What are the operating voltage and temperature ranges for these devices?
Both the AT25DF081A-SSH-T and AT25DF041A-SH-B operate from a single 2.7 V to 3.6 V supply. The industrial temperature range for both parts is -40 °C to +85 °C, as specified in the respective manufacturer datasheets.
Can the AT25DF041A-SH-B be used as a drop-in replacement for the AT25DF081A-SSH-T?
Not directly. Although the pin functions and SPI interface are compatible, the AT25DF041A-SH-B has half the density (4 Mbit versus 8 Mbit) and a different package body width. Firmware that addresses the full 8-Mbit array of the AT25DF081A-SSH-T will not work correctly with the 4-Mbit device, and the PCB land pattern must be checked for the wider SOIC body.
What are the erase block sizes for the AT25DF081A-SSH-T and AT25DF041A-SH-B?
Both devices support 256-byte page programming and offer sector erase (4 KByte), block erase (32 KByte and 64 KByte), and full-chip erase options, consistent with the AT25DF series architecture. Designers should confirm the exact erase granularity in the respective datasheet before finalizing firmware.
Which part should be selected for a design requiring 8 Mbit of SPI flash?
The AT25DF081A-SSH-T should be selected when 8 Mbit (1 MByte) of SPI serial flash is required, as the AT25DF041A-SH-B provides only 4 Mbit (512 KByte). Both parts share the same interface and voltage range, so the selection is driven primarily by density and package footprint requirements.