25LC640AXT-E/ST Microchip Technology, 25LC640AXT-E/ST Datasheet - Page 12

• Manufacturer Part Number: 25LC640AXT-E/ST
• Description: 64K, 8K X 8, 2.5V SER EE EXT, ROTATED PINOUT 8 TSSOP 4.4mm T/R
• Manufacturer: Microchip Technology

Specifications of 25LC640AXT-E/ST

• Format - Memory: EEPROMs - Serial
• Memory Type: EEPROM
• Memory Size: 64K (8K x 8)
• Speed: 10MHz
• Interface: SPI, 3-Wire Serial
• Voltage - Supply: 2.5 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Package / Case: 8-TSSOP
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: 25LC640AXT-E/STTR

25AA640A/25LC640A
2.7
The following protection has been implemented to
prevent inadvertent writes to the array:
• The write enable latch is reset on power-up
• A write enable instruction must be issued to set
• After a byte write, page write or STATUS register
• CS must be set high after the proper number of
• Access to the array during an internal write cycle
TABLE 2-4:
DS21830D-page 12
x = don’t care
the write enable latch
write, the write enable latch is reset
clock cycles to start an internal write cycle
is ignored and programming is continued
(SR bit 1)
WEL
0
1
1
1
Data Protection
WRITE-PROTECT FUNCTIONALITY MATRIX
(SR bit 7)
WPEN
x
0
1
1
1 (high)
0 (low)
(pin 3)
WP
x
x
Protected Blocks
Protected
Protected
Protected
Protected
2.8
The 25XX640A powers on in the following state:
• The device is in low-power Standby mode
• The write enable latch is reset
• SO is in high-impedance state
• A high-to-low-level transition on CS is required to
(CS = 1)
enter active state
Unprotected Blocks
Power-On State
Protected
Writable
Writable
Writable
© 2008 Microchip Technology Inc.
STATUS Register
Protected
Protected
Writable
Writable