Description
The Adesto® AT25DF081A is a serial interface Flash memory device designed for use in a wide variety of high-volume consumer based applications in which program code is shadowed from Flash memory into embedded or
external RAM for execution. The flexible erase architecture of the AT25DF081A, with its erase granularity as small
as 4-Kbytes, makes it ideal for data storage as well, eliminating the need for additional data storage EEPROM
devices.
The physical sectoring and the erase block sizes of the AT25DF081A have been optimized to meet the needs of
today's code and data storage applications. By optimizing the size of the physical sectors and erase blocks, the
memory space can be used much more efficiently. Because certain code modules and data storage segments
must reside by themselves in their own protected sectors, the wasted and unused memory space that occurs with
large sectored and large block erase Flash memory devices can be greatly reduced. This increased memory space
efficiency allows additional code routines and data storage segments to be added while still maintaining the same
overall device density.
The AT25DF081A also offers a sophisticated method for protecting individual sectors against erroneous or malicious program and erase operations. By providing the ability to individually protect and unprotect sectors, a system
can unprotect a specific sector to modify its contents while keeping the remaining sectors of the memory array
securely protected. This is useful in applications where program code is patched or updated on a subroutine or
module basis, or in applications where data storage segments need to be modified without running the risk of
errant modifications to the program code segments. In addition to individual sector protection capabilities, the
AT25DF081A incorporates Global Protect and Global Unprotect features that allow the entire memory array to be
either protected or unprotected all at once. This reduces overhead during the manufacturing process since sectors
do not have to be unprotected one-by-one prior to initial programming.
To take code and data protection to the next level, the AT25DF081A incorporates a sector lockdown mechanism
that allows any combination of individual 64-Kbyte sectors to be locked down and become permanently read-only.
This addresses the need of certain secure applications that require portions of the Flash memory array to be permanently protected against malicious attempts at altering program code, data modules, security information, or
encryption/decryption algorithms, keys, and routines. The device also contains a specialized OTP (One-Time Programmable) Security Register that can be used for purposes such as unique device serialization, system-level
Electronic Serial Number (ESN) storage, locked key storage, etc.
Specifically designed for use in 3-volt systems, the AT25DF081A supports read, program, and erase operations
with a supply voltage range of 2.7V to 3.6V. No separate voltage is required for programming and erasing.

Features
• Single 2.7V - 3.6V Supply
• Serial Peripheral Interface (SPI) Compatible
– Supports SPI Modes 0 and 3
– Supports RapidS™ Operation
– Supports Dual-Input Program and Dual-Output Read
• Very High Operating Frequencies
– 100MHz for RapidS
– 85MHz for SPI
– Clock-to-Output (tV) of 5ns Maximum
• Flexible, Optimized Erase Architecture for Code + Data Storage Applications
– Uniform 4-Kbyte Block Erase
– Uniform 32-Kbyte Block Erase
– Uniform 64-Kbyte Block Erase
– Full Chip Erase
• Individual Sector Protection with Global Protect/Unprotect Feature
– 16 Sectors of 64-Kbytes Each
• Hardware Controlled Locking of Protected Sectors via WP Pin
• Sector Lockdown
– Make Any Combination of 64-Kbyte Sectors Permanently Read-Only
• 128-Byte Programmable OTP Security Register
• Flexible Programming
– Byte/Page Program (1- to 256-Bytes)
• Fast Program and Erase Times
– 1.0ms Typical Page Program (256 Bytes) Time
– 50ms Typical 4-Kbyte Block Erase Time
– 250ms Typical 32-Kbyte Block Erase Time
– 400ms Typical 64-Kbyte Block Erase Time
• Automatic Checking and Reporting of Erase/Program Failures
• Software Controlled Reset
• JEDEC Standard Manufacturer and Device ID Read Methodology
• Low Power Dissipation
– 5mA Active Read Current (Typical at 20MHz)
– 5µA Deep Power-Down Current (Typical)
• Endurance: 100,000 Program/Erase Cycles
• Data Retention: 20 Years
• Complies with Full Industrial Temperature Range
• Industry Standard Green (Pb/Halide-free/RoHS Compliant) Package Options
– 8-lead SOIC (150-mil and 208-mil wide)
– 8-pad Ultra Thin DFN (5 x 6 x 0.6mm)