2001 Microchip Technology Inc.
DS21223E-page 1
M
25AA640/25LC640
Device Selection Table
Features
Low power CMOS technology
- Write current: 3 mA typical
- Read current: 500
A 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
Description
The Microchip Technology Inc. 25AA640/25LC640
(25XX640
*
) is a 64K bit Serial Electrically Erasable
PROM [EEPROM]. The memory is accessed via a sim-
ple 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, transi-
tions on its inputs will be ignored, with the exception of
chip select, allowing the host to service higher priority
interrupts.
Block Diagram
Package Types
Part
Number
V
CC
Range
Max Clock
Frequency
Temp
Ranges
25AA640
1.8-5.5V
1 MHz
I
25LC640
2.5-5.5V
2 MHz
I
25LC640
4.5-5.5V
3/2.5 MHz
I, E
SI
SO
SCK
CS
HOLD
WP
Status
Register
I/O Control
Memory
Control
Logic
X
Dec
HV Generator
EEPROM
Array
Page Latches
Y Decoder
Sense Amp.
R/W Control
Logic
V
CC
V
SS
25XX6
40
25XX6
40
PDIP/SOIC
TSSOP
CS
SO
WP
V
SS
V
CC
HOLD
SCK
SI
8
7
6
5
1
2
3
4
8
7
6
5
1
2
3
4
HOLD
V
CC
CS
SO
SCK
SI
V
SS
WP
64K SPITM Bus Serial EEPROM
*25XX640 is used in this document as a generic part number for the 25AA640/25LC640 devices.
25AA640/25LC640
DS21223E-page 2
2001 Microchip Technology Inc.
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
V
CC
.............................................................................................................................................................................7.0V
All inputs and outputs w.r.t. V
SS
.......................................................................................................... -0.6V to V
CC
+1.0V
Storage temperature .................................................................................................................................-65C to 150C
Ambient temperature under bias ...............................................................................................................-65C to 125C
Soldering temperature of leads (10 seconds) ....................................................................................................... +300C
ESD protection on all pins .......................................................................................................................................... 4 kV
NOTICE: Stresses above those listed under `Maximum ratings' may cause permanent damage to the device. This
is a stress rating only and functional operation of the device at those or any other conditions above those indicated in
the operational listings of this specification is not implied. Exposure to maximum rating conditions for an extended
period of time may affect device reliability.
25AA640/25LC640
DS21223E-page 4
2001 Microchip Technology Inc.
1.2
AC Characteristics
AC Characteristics
Industrial (I):
T
AMB
= -40C to +85C
V
CC
= 1.8V to 5.5V
Automotive (E): T
AMB
= -40C to +125C
V
CC
= 4.5V to 5.5V
Param.
No.
Sym
Characteristic
Min
Max
Units
Conditions
1
F
CLK
Clock Frequency
--
--
--
3
2
1
MHz
MHz
MHz
V
CC
= 4.5V to 5.5V (Note 2)
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
2
T
CSS
CS Setup Time
100
250
500
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
3
T
CSH
CS Hold Time
150
250
475
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
4
T
CSD
CS Disable Time
500
--
ns
5
T
SU
Data Setup Time
30
50
50
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
6
T
HD
Data Hold Time
50
100
100
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
7
T
R
CLK Rise Time
--
2
s
(Note 1)
8
T
F
CLK Fall Time
--
2
s
(Note 1)
9
T
HI
Clock High Time
150
230
475
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
10
T
LO
Clock Low Time
150
230
475
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
11
T
CLD
Clock Delay Time
50
--
ns
12
T
CLE
Clock Enable Time
50
--
ns
13
T
V
Output Valid from
Clock Low
--
--
--
150
230
475
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
14
T
HO
Output Hold Time
0
--
ns
(Note 1)
15
T
DIS
Output Disable Time
--
--
--
200
250
500
ns
ns
ns
V
CC
= 4.5V to 5.5V (Note 1)
V
CC
= 2.5V to 5.5V (Note 1)
V
CC
= 1.8V to 5.5V (Note 1)
16
T
HS
HOLD Setup Time
100
100
200
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
17
T
HH
HOLD Hold Time
100
100
200
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
18
T
HZ
HOLD Low to Output
High-Z
100
150
200
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V (Note 1)
V
CC
= 2.5V to 5.5V (Note 1)
V
CC
= 1.8V to 5.5V (Note 1)
19
T
HV
HOLD High to Output
Valid
100
150
200
--
--
--
ns
ns
ns
V
CC
= 4.5V to 5.5V
V
CC
= 2.5V to 5.5V
V
CC
= 1.8V to 5.5V
20
T
WC
Internal Write Cycle
Time
--
5
ms
21
--
Endurance
100 k
--
E/W
Cycles
(Note 3)
Note
1: This parameter is periodically sampled and not 100% tested.
2: F
CLK
max. = 2.5 MHz for T
AMB
> 85C.
3: This parameter is not tested but established by characterization. For endurance estimates in a specific application,
please consult the Total Endurance Model which can be obtained on our website.
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