Part A
AT45DB321E-SHF-B
Adesto Technologies
- Lifecycle
- Active
- Stock
- 2389 PCS
- Package
- SOIC-8
- Series
- Memory
Replacement verdict
Compatible functional replacement candidate
The AT45DB321E-SHF-B is a higher-density DataFlash device in the same SOIC-8 wide-body family as the AT45DB161E-SHD-B, sharing the Serial Peripheral Interface, supply voltage range, and page-based architecture. It is a viable functional replacement candidate where the host firmware can accommodate the larger 32-Mbit density and the correspondingly larger page and block sizes, but it is not a direct drop-in substitute without firmware and timing validation.
Memory Density
Validation required
Interface Type
High match
Supply Voltage Range
High match
Package Type
Validation required
Parts at a glance
Part B
AT45DB161E-SHD-B
Adesto Technologies
- Lifecycle
- Active
- Stock
- 1556 PCS
- Package
- SOIC-8
- Series
- Memory
Key differences
Rows are prioritized by design impact. Highlighted values require attention during substitution.
Key electrical and mechanical differences between the two devices
| Parameter | AT45DB161E-SHD-B | AT45DB321E-SHF-B | Why it matters |
|---|---|---|---|
| Memory Density | 16 Mbit | 32 Mbit | Density determines total storage capacity; a 32 Mbit device holds twice the data of a 16 Mbit device, so they are not directly interchangeable where capacity is fixed by firmware or data logging requirements. |
| Page Size | 512 bytes (528 bytes with ECC) | 512 bytes (528 bytes with ECC) | Page size affects write granularity and buffer management; matching page sizes simplifies firmware portability between the two devices. |
| Number of Pages | 4096 pages | 8192 pages | Page count combined with page size defines total array size and address range; differing page counts require address map changes in software. |
| Supply Voltage Range | 2.5 V to 3.6 V | 2.3 V to 3.6 V | The wider low-voltage range of the 32 Mbit part allows operation at lower supply rails, which can matter in battery-powered designs. |
| Maximum Clock Frequency | 85 MHz | 85 MHz | Clock frequency determines maximum SPI throughput; identical ratings mean timing budgets remain valid when swapping parts. |
| Package / Case | 8-SOIC (0.209", 5.30mm width) | 8-SOIC (0.209", 5.30mm width) | Package footprint and pinout must match for board-level drop-in compatibility; identical SOIC-8 packages allow the same PCB land pattern. |
| Interface Type | SPI (Serial Peripheral Interface) | SPI (Serial Peripheral Interface) | A common SPI interface means the same host controller and driver framework can be reused across both devices. |
| Operating Temperature Range | -40°C to +85°C | -40°C to +85°C | Industrial temperature range compatibility ensures both parts suit the same environmental conditions in the target application. |
| Organization | 16 Mbit organized as 4096 pages x 512/528 bytes | 32 Mbit organized as 8192 pages x 512/528 bytes | Array organization affects addressing and buffer-to-page mapping; differing page counts require firmware address recalculation. |
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 | AT45DB321E-SHF-B | AT45DB161E-SHD-B |
|---|---|---|
| Part Status | Active | Not For New Designs |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | FLASH | FLASH |
| Technology | FLASH | FLASH |
| Memory Size | 32Mb (528 Bytes x 8192 pages) | 16Mb (528 Bytes x 4096 pages) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 85 MHz | 85 MHz |
| Write Cycle Time - Word Page | 8µs, 4ms | 8µs, 4ms |
| Voltage - Supply | 2.3V ~ 3.6V | 2.5V ~ 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 AT45DB161E-SHD-B and AT45DB321E-SHF-B?
The AT45DB161E-SHD-B is a 16-Mbit (2-MByte) DataFlash device, while the AT45DB321E-SHF-B is a 32-Mbit (4-MByte) DataFlash device. Both are from the Adesto (now Renesas) AT45DBxxxE family and use the same SPI interface and command set, but they differ in density, page size, and package. The AT45DB161E-SHD-B uses 512-byte pages (528 bytes with ECC) and is offered in an 8-lead SOIC package (SHD suffix). The AT45DB321E-SHF-B uses 512-byte pages (528 bytes with ECC) and is offered in an 8-lead SOIC package (SHF suffix). The primary difference is memory density: 16 Mbit versus 32 Mbit.
Are the AT45DB161E-SHD-B and AT45DB321E-SHF-B pin-compatible?
Both devices are offered in 8-lead SOIC packages (208-mil body width) with the same pinout: CS, SO, WP, GND, VCC, SCK, RESET, and SI. Because they share the same package type and pinout, they are pin-compatible in the same 8-lead SOIC footprint. However, designers should verify the specific package drawing and land pattern in the respective datasheets before substituting one for the other.
Do the AT45DB161E-SHD-B and AT45DB321E-SHF-B use the same SPI command set?
Yes. Both devices are part of the AT45DBxxxE family and support the same standard SPI command set, including Read Array, Page Program, Page Erase, Block Erase, Chip Erase, and status register read. The command opcodes and protocol are compatible across the family, so firmware written for one density can generally be adapted to the other by adjusting address ranges and page/block counts.
What are the operating voltage and temperature ranges for these devices?
Both the AT45DB161E-SHD-B and AT45DB321E-SHF-B operate from a single 2.5V to 3.6V supply. The industrial temperature range for both devices is -40°C to +85°C. These parameters are specified in the respective manufacturer datasheets and are consistent across the AT45DBxxxE family.
Can the AT45DB321E-SHF-B be used as a drop-in replacement for the AT45DB161E-SHD-B?
Because both devices share the same 8-lead SOIC package and pinout, the AT45DB321E-SHF-B can be placed on a board designed for the AT45DB161E-SHD-B. However, it is not a true drop-in replacement in terms of firmware: the higher density means different page counts, block counts, and address ranges. Firmware must be updated to use the correct address boundaries and device ID. Designers should validate the substitution against the target design and manufacturer documentation.
What is the page size and organization of each device?
The AT45DB161E-SHD-B is organized as 4,096 pages of 512 bytes (528 bytes with ECC), totaling 16 Mbit. The AT45DB321E-SHF-B is organized as 8,192 pages of 512 bytes (528 bytes with ECC), totaling 32 Mbit. Both devices support page erase, block erase, and chip erase operations, and both include two SRAM data buffers of 512 bytes each for program and read operations.
What is the maximum SPI clock frequency supported by these devices?
Both the AT45DB161E-SHD-B and AT45DB321E-SHF-B support a maximum SPI clock frequency of 85 MHz for standard read and program operations. This is specified in the manufacturer datasheets for the AT45DBxxxE family and applies to both densities.