Part A
AT45DB161D-TU
Adesto Technologies
- Lifecycle
- Active
- Stock
- 7667 Stückzahl
- Package
- TSSOP-28
- Series
- Speicher
Replacement verdict
Compatible functional replacement candidate
The AT45DB021D-SSH-T is a lower-density member of the same DataFlash family as the AT45DB161D-TU, sharing the same serial interface, command set, and page-based architecture. It can serve as a functional substitute only where the reduced 2-Mbit density and smaller page size are acceptable; the differing density, page size, and package footprint require design validation before substitution.
Memory Density
Validation required
Page Size
Validation required
Interface Type
High match
Package Type
Not compatible
Parts at a glance
Part B
AT45DB021D-SSH-T
Adesto Technologies
- Lifecycle
- Active
- Stock
- 7329 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 | AT45DB161D-TU | AT45DB021D-SSH-T | Why it matters |
|---|---|---|---|
| Memory Density | 16 Mbit (2 M x 8) | 2 Mbit (256 K x 8) | Density determines total storage capacity; the two parts differ by 8x, so they are not drop-in substitutes for firmware or data storage sizing. |
| Page Size | 512 bytes (standard) / 528 bytes (binary) | 256 bytes (standard) / 264 bytes (binary) | Page size affects write granularity and buffer addressing; different page sizes require firmware changes for program and read operations. |
| Number of Pages | 4096 pages | 1024 pages | Page count combined with page size defines total array organization and address map; differing counts change address decoding. |
| Interface Type | SPI (Serial Peripheral Interface) | SPI (Serial Peripheral Interface) | Both use SPI, so bus compatibility is maintained, though command sets and addressing differ due to density. |
| Supply Voltage Range | 2.7 V to 3.6 V | 2.5 V to 3.6 V | Operating voltage range affects compatibility with host systems; the wider low-end range of the 2 Mbit part may allow lower-voltage operation. |
| Maximum Clock Frequency | 66 MHz | 66 MHz | Clock rate determines maximum data throughput; identical ratings mean similar bus timing performance. |
| Package / Mounting | 28-lead TSOP (surface mount) | 8-lead SOIC (surface mount) | Package footprint and pin count differ, so PCB layout and assembly are not interchangeable between the two parts. |
| Operating Temperature Range | -40 °C to +85 °C | -40 °C to +85 °C | Temperature range indicates environmental robustness; identical industrial ranges mean similar application suitability. |
| SRAM Data Buffer Size | 2 x 512 bytes | 2 x 256 bytes | Buffer size affects page programming and read-modify-write efficiency; smaller buffers on the 2 Mbit part change data handling routines. |
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 | AT45DB161D-TU | AT45DB021D-SSH-T |
|---|---|---|
| Supplier | - | Dialog Semiconductor GmbH |
| Part Status | Obsolete | Obsolete |
| Memory Type | Non-Volatile | Non-Volatile |
| Memory Format | FLASH | FLASH |
| Technology | FLASH | FLASH |
| Memory Size | 16Mb (528 Bytes x 4096 pages) | 2Mb (264 Bytes x 1024 pages) |
| Memory Interface | SPI | SPI |
| Clock Frequency | 66 MHz | 66 MHz |
| Write Cycle Time - Word Page | 6ms | 4ms |
| 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 AT45DB161D-TU and the AT45DB021D-SSH-T?
The AT45DB161D-TU is a 16-Mbit (2-MByte) DataFlash memory device in a 28-pin TSOP package, while the AT45DB021D-SSH-T is a 2-Mbit (256-KByte) DataFlash device in an 8-pin SOIC package. They differ in density, package, pin count, and page size, so they are not drop-in replacements for each other.
What is the memory density and organization of each device?
The AT45DB161D-TU provides 16 Mbits organized as 4,096 pages of 512 bytes (or 528 bytes) each. The AT45DB021D-SSH-T provides 2 Mbits organized as 1,024 pages of 256 bytes (or 264 bytes) each. The page sizes and total page counts differ between the two devices.
What supply voltage range do these DataFlash devices require?
Both the AT45DB161D-TU and AT45DB021D-SSH-T operate from a single 2.7 V to 3.6 V supply, per the Atmel (now Microchip) datasheets for the AT45DB161D and AT45DB021D families.
What SPI interface and maximum clock frequency do these devices support?
Both devices use a standard Serial Peripheral Interface (SPI) and support clock frequencies up to 66 MHz for rapid random access reads, per the respective manufacturer datasheets. The interface is compatible in protocol, but command set and addressing differ due to density.
Are the packages of the AT45DB161D-TU and AT45DB021D-SSH-T interchangeable on a PCB?
No. The AT45DB161D-TU uses a 28-pin TSOP package, while the AT45DB021D-SSH-T uses an 8-pin SOIC package. The pin counts, footprint dimensions, and pin assignments differ, so they cannot share the same PCB land pattern without redesign.
Can the AT45DB021D-SSH-T be used as a direct substitute for the AT45DB161D-TU in an existing design?
No. Although both are SPI DataFlash devices from the same family, the AT45DB021D-SSH-T has one-eighth the density, a different page size, a different package, and a different pinout. A direct substitution would require firmware and hardware changes and is not supported without validation against the target design.
What are the typical operating temperature ranges for these devices?
The AT45DB161D-TU is specified for the industrial temperature range of -40°C to +85°C. The AT45DB021D-SSH-T is also specified for the industrial temperature range of -40°C to +85°C, per the manufacturer datasheets.
Do both devices support page erase and block erase operations?
Yes. Both the AT45DB161D-TU and AT45DB021D-SSH-T support page erase, block erase, and chip erase operations, as well as page program and buffer write operations, per their respective datasheets. The specific block sizes and erase command addressing differ due to density.