25AA640A/25LC640A
64K SPI Bus Serial EEPROM
Device Selection Table
Part Number
VCC Range
Page Size
Temp. Ranges
Packages
25LC640A
25AA640A
2.5-5.5V
1.8-5.5V
32 Byte
32 Byte
I,E
I
P, SN, ST, MS, MF, MNY
P, SN, ST, MS, MF, MNY
Features:
Description:
• Max. Clock 10 MHz
The Microchip Technology Inc. 25AA640A/25LC640A
(25XX640A*) are 64 kbit 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 sep-
arate data in (SI) and data out (SO) lines. Access to the
device is controlled through a Chip Select (CS) input.
• 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
• 8192 x 8-bit Organization
• 32 Byte Page
Communication to the device can be paused via the
hold pin (HOLD). While the device is paused, transi-
tions on its inputs will be ignored, with the exception of
Chip Select, allowing the host to service higher priority
interrupts.
• 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
The 25XX640A is available in standard packages
including 8-lead PDIP and SOIC, and advanced
packaging including 8-lead MSOP, 8-lead TSSOP, DFN
and TDFN.
- Power-on/off data protection circuitry
- Write enable latch
- Write-protect pin
• Sequential Read
• High Reliability
Package Types (not to scale)
- Endurance: 1,000,000 erase/write cycles
- Data retention: > 200 years
- ESD protection: > 4000V
• Temperature Ranges Supported:
PDIP/SOIC
(P, SN)
TSSOP/MSOP
(ST, MS)
1
2
3
4
8
7
6
5
CS
SO
WP
V
CC
CS
SO
WP
1
2
3
4
8
7
6
5
VCC
HOLD
SCK
SI
HOLD
SCK
SI
- Industrial (I):
-40°C to +85°C
VSS
- Automotive (E):
-40°C to +125°C
VSS
DFN/TDFN
(MF/MNY)
X-Rotated TSSOP
(X/ST)
1
CS
SO
8
VCC
1
2
3
4
8
7
6
5
HOLD
SCK
SI
2
3
4
7
6
5
V
CC
HOLD
SCK
SI
CS
SO
VSS
WP
VSS
WP
* 25XX640A is used in this document as a generic part number
for the 25AA640A, 25LC640A devices.
© 2008 Microchip Technology Inc.
DS21830D-page 1