25AA256 Datasheet, PDF (1/26 Pages) Microchip Technology – 256K SPI Bus Serial EEPROM

25AA256/25LC256
256K SPI^™ Bus Serial EEPROM
Device Selection Table
Part Number
25LC256
25AA256
VCC Range
2.5-5.5V
1.8-5.5V
Page Size
64 Byte
64 Byte
Temp. Ranges
I, E
I
Packages
P, SN, ST, MF
P, SN, ST, MF
Features
Description
• Max. clock 10 MHz
• Low-power CMOS technology
- Max. Write Current: 5 mA at 5.5V, 10 MHz
- Read Current: 5 mA at 5.5V, 10 MHz
- Standby Current: 1 µA at 5.5V
• 32,768 x 8-bit organization
• 64 byte page
• Self-timed ERASE and WRITE cycles (5 ms
max.)
• Block write protection
- Protect none, 1/4, 1/2 or all of array
• Built-in write protection
- Power-on/off data protection circuitry
- Write enable latch
- Write-protect pin
• Sequential read
• High reliability
- Endurance: 1,000,000 erase/write cycles
- Data retention: > 200 years
- ESD protection: > 4000V
• Temperature ranges supported;
- Industrial (I):
- Automotive (E):
-40°C to +85°C
-40°C to +125°C
• Standard and Pb-free packages available
Pin Function Table
Name
Function
CS
Chip Select Input
SO
Serial Data Output
WP
Write-Protect
VSS
Ground
SI
SCK
Serial Data Input
Serial Clock Input
HOLD Hold Input
VCC
Supply Voltage
The Microchip Technology Inc. 25AA256/25LC256
(25XX256^*) are 256k-bit Serial Electrically Erasable
PROMs. The memory is accessed via a simple Serial
Peripheral Interface™ (SPI™) compatible serial bus.
The bus signals required are a clock input (SCK) plus
separate data in (SI) and data out (SO) lines. Access to
the device is controlled through a Chip Select (CS)
input.
Communication to the device can be paused via the
hold pin (HOLD). While the device is paused,
transitions on its inputs will be ignored, with the
exception of Chip Select, allowing the host to service
higher priority interrupts.
The 25XX256 is available in standard packages
including 8-lead PDIP and SOIC, and advanced
packaging including 8-lead DFN and 8-lead TSSOP.
Pb-free (Pure Sn) finish is also available.
Package Types (not to scale)
TSSOP
(ST)
PDIP/SOIC
(P, SN)
CS ¹
SO 2
WP ³
VSS ⁴
8 _VCC
7 _HOLD
6 _SCK
5 _SI
CS 1
SO 2
WP 3
VSS 4
8 VCC
7 HOLD
6 SCK
5 SI
DFN
(MF)
CS 1
SO 2
WP 3
VSS 4
8 VCC
7 HOLD
6 SCK
5 SI
SPI is a registered trademark of Motorola Corporation.
* 25XX256 is used in this document as a generic part number for the 25AA256, 25LC256 devices.
 2003 Microchip Technology Inc.
Preliminary
DS21822C-page 1