25AA640_08 Datasheet, PDF (1/24 Pages) Microchip Technology – 64K SPI Bus Serial EEPROM

Not recommended for new designs –
Please use 25AA640A or 25LC640A.
25AA640/25LC640
64K SPI Bus Serial EEPROM
Device Selection Table
Part
Number
VCC
Range
Max Clock
Frequency
25AA640
25LC640
25LC640
1.8-5.5V
2.5-5.5V
4.5-5.5V
1 MHz
2 MHz
3/2.5 MHz
Temp
Ranges
I
I
I, E
Features:
• Low-Power CMOS Technology
- Write current: 3 mA, typical
- Read current: 500 μA, typical
- Standby current: 500 nA, typical
• 8192 x 8 Bit Organization
• 32 Byte Page
• Write Cycle Time: 5 ms max.
• Self-Timed Erase and Write Cycles
• 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
- Data retention: > 200 years
- ESD protection: > 4000V
• 8-pin PDIP, SOIC and TSSOP Packages
• Temperature Ranges Supported:
- Industrial (I): -40°C to +85°C
- Automotive (E): -40°C to +125°C
Package Types
CS
SO
WP
VSS
PDIP/SOIC
1
8 VCC
2
7 HOLD
3
6 SCK
4
5 SI
Description:
The Microchip Technology Inc. 25AA640/25LC640
(25XX640^*) is a 64 Kbit Serial Electrically Erasable
PROM [EEPROM]. 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.
Block Diagram
STATUS
Register
HV Generator
I/O Control
Logic
Memory
Control
Logic
XDEC
EEPROM
Array
Page
Latches
SI
SO
CS
SCK
HOLD
WP
VCC
VSS
Y Decoder
Sense Amp.
R/W Control
TSSOP
HOLD 1
VCC 2
CS 3
SO 4
8 SCK
7 SI
6 VSS
5 WP
*25XX640 is used in this document as a generic part number for the 25AA640/25LC640 devices.
© 2008 Microchip Technology Inc.
DS21223H-page 1