Features
• Serial Peripheral Interface (SPI) Compatible
• Supports SPI Modes 0 (0,0) and 3 (1,1)
– Datasheet Describes Mode 0 Operation
• Low-voltage and Standard-voltage Operation
– 1.8 (VCC = 1.8V to 5.5V)
• 20MHz Clock Rate (5V)
• 32-byte Page Mode
• Block Write Protection
SPI Serial
EEPROMs
32K (4096 x 8)
64K (8192 x 8)
– Protect 1/4, 1/2, or Entire Array
• Write Protect (WP) Pin and Write Disable Instructions for Both Hardware and Software
Data Protection
• Self-timed Write Cycle (5ms max)
• High Reliability
– Endurance: One Million Write Cycles
– Data Retention: 100 Years
• Green (Pb/Halide-free/RoHS Compliant) Packaging Options
• Die Sales: Wafer Form, Tape and Reel, and Bumped Wafers
Atmel
Description
AT25320B
AT25640B
The Atmel® AT25320B/640B provides 32768-/65536-bits of serial electrically-erasable
programmable read-only memory (EEPROM) organized as 4096/8192 words of 8-bits
each. The device is optimized for use in many industrial and commercial applications
where low-power and low-voltage operation are essential. The AT25320B/640B is
available in space-saving 8-lead JEDEC SOIC, 8-lead UDFN, 8-lead XDFN, 8-lead
TSSOP, and 8-ball VFBGA packages.
The AT25320B/640B is enabled through the Chip Select pin (CS) and accessed via a
three-wire interface consisting of Serial Data Input (SI), Serial Data Output (SO), and
Serial Clock (SCK). All programming cycles are completely self-timed, and no sepa-
rate erase cycle is required before write.
Table 0-1.
Pin Configuration
8-lead SOIC
8-lead TSSOP
Pin Name Function
CS
SO
VCC
CS
SO
1
2
3
4
8
7
6
5
VCC
1
2
3
4
8
7
6
5
HOLD
SCK
SI
HOLD
SCK
SI
CS
Chip Select
WP
WP
SCK
SI
Serial Data Clock
Serial Data Input
Serial Data Output
Ground
GND
GND
8-lead UDFN
8-lead XDFN
SO
8
7
6
5
1
2
3
4
8
7
6
5
1
2
3
4
VCC
CS
SO
VCC
CS
GND
VCC
WP
HOLD
SCK
SI
HOLD
SCK
SI
SO
Power Supply
Write Protect
WP
WP
GND
GND
Bottom View
Bottom View
HOLD
Suspends Serial Input
8-ball VFBGA
VCC
8
7
6
5
1
2
3
4
CS
SO
HOLD
SCK
SI
WP
GND
8535F–SEEPR–6/10
Bottom View