25AA256/25LC256
256K SPI
™
Bus Serial EEPROM
Device Selection Table
Part Number
25LC256
25AA256
V
CC
Range
2.5-5.5V
1.8-5.5V
Page Size
64 Byte
64 Byte
Temp. Ranges
I, E
I
Packages
P, SN, ST, MF
P, SN, ST, MF
Features
• Max. clock 10 MHz
• 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
• 32,768 x 8-bit organization
• 64 byte page
• 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
- Power-on/off data protection circuitry
- Write enable latch
- Write-protect pin
• Sequential read
• High reliability
- Endurance: 1,000,000 erase/write cycles
- Data retention: > 200 years
- ESD protection: > 4000V
• Temperature ranges supported;
- Industrial (I):
-40°C to +85°C
- Automotive (E):
-40°C to +125°C
• Standard and Pb-free packages available
Description
The Microchip Technology Inc. 25AA256/25LC256
(25XX256
*
) are 256k-bit 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
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.
The 25XX256 is available in standard packages
including 8-lead PDIP and SOIC, and advanced
packaging including 8-lead DFN and 8-lead TSSOP.
Pb-free (Pure Sn) finish is also available.
Package Types (not to scale)
TSSOP
(ST)
CS
SO
WP
V
SS
1
2
3
4
8
7
6
5
V
CC
HOLD
SCK
SI
PDIP/SOIC
(P, SN)
CS
SO
WP
V
SS
1
2
3
4
8
7
6
5
V
CC
HOLD
SCK
SI
25LC256
Pin Function Table
Name
CS
SO
WP
V
SS
SI
SCK
HOLD
V
CC
Function
Chip Select Input
Serial Data Output
Write-Protect
Ground
Serial Data Input
Serial Clock Input
Hold Input
Supply Voltage
CS 1
DFN
(MF)
8
25LC256
7
6
5
V
CC
HOLD
SCK
SI
SO 2
WP 3
V
SS
4
SPI is a registered trademark of Motorola Corporation.
* 25XX256 is used in this document as a generic part number for the 25AA256, 25LC256 devices.
2003 Microchip Technology Inc.
Preliminary
DS21822C-page 1
25AA256/25LC256
1.0
ELECTRICAL CHARACTERISTICS
Absolute Maximum Ratings
(†)
V
CC
.............................................................................................................................................................................6.5V
All inputs and outputs w.r.t. V
SS
......................................................................................................... -0.6V to V
CC
+1.0V
Storage temperature .................................................................................................................................-65°C to 150°C
Ambient temperature under bias ...............................................................................................................-40°C to 125°C
ESD protection on all pins ..........................................................................................................................................4 kV
†
NOTICE: Stresses above those listed under “Absolute 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.
TABLE 1-1:
DC CHARACTERISTICS
Industrial (I):
T
A
= -40°C to +85°C
Automotive (E): T
A
= -40°C to +125°C
Min.
.7 V
CC
-0.3
-0.3
—
—
V
CC
-0.5
—
—
—
Max.
V
CC
+1
0.3V
CC
0.2V
CC
0.4
0.2
—
±1
±1
7
Units
V
V
V
V
V
V
µA
µA
pF
V
CC
≥
2.7V
V
CC
< 2.7V
I
OL
= 2.1 mA
I
OL
= 1.0 mA, V
CC
< 2.5V
I
OH
= -400
µA
CS = V
CC
, V
IN
= V
SS TO
V
CC
CS = V
CC
, V
OUT
= V
SS TO
V
CC
T
A
= 25°C, CLK = 1.0 MHz,
V
CC
= 5.0V
(Note)
V
CC
= 5.5V; F
CLK
= 10.0 MHz;
SO = Open
V
CC
= 2.5V; F
CLK
= 5.0 MHz;
SO = Open
V
CC
= 5.5V
V
CC
= 2.5V
CS = V
CC
= 5.5V, Inputs tied to V
CC
or
V
SS
, 125°C
CS = V
CC
= 5.5V, Inputs tied to V
CC
or
V
SS
, 85°C
V
CC
= 1.8V to 5.5V
V
CC
= 2.5V to 5.5V
Test Conditions
DC CHARACTERISTICS
Param.
No.
D001
D002
D003
D004
D005
D006
D007
D008
D009
Sym.
V
IH1
V
IL1
V
IL2
V
OL
V
OL
V
OH
I
LI
I
LO
C
INT
Characteristic
High-level input
voltage
Low-level input
voltage
Low-level output
voltage
High-level output
voltage
Input leakage current
Output leakage
current
Internal Capacitance
(all inputs and
outputs)
D010
I
CC
Read
Operating Current
—
—
5
2.5
mA
mA
mA
mA
µA
µA
D011
D012
I
CC
Write
I
CCS
Standby Current
—
—
—
—
5
3
5
1
Note:
This parameter is periodically sampled and not 100% tested.
DS21822C-page 2
Preliminary
2003 Microchip Technology Inc.
25AA256/25LC256
TABLE 1-2:
AC CHARACTERISTICS
Industrial (I):
T
A
= -40°C to +85°C
Automotive (E): T
A
= -40°C to +125°C
Min.
—
—
—
50
100
150
100
200
250
50
10
20
30
20
40
50
—
—
50
100
150
50
100
150
50
50
—
—
—
0
—
—
—
20
40
80
Max.
10
5
3
—
—
—
—
—
—
—
—
—
—
—
—
—
2
2
—
—
—
—
—
—
—
—
50
100
160
—
40
80
160
—
—
—
Units
MHz
MHz
MHz
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
µs
µs
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
V
CC
= 1.8V to 5.5V
V
CC
= 2.5V to 5.5V
Test Conditions
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
—
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
(Note 1)
(Note 1)
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
—
—
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
(Note 1)
4.5V
≤
Vcc
≤
5.5V(Note
1)
2.5V
≤
Vcc
≤
4.5V(Note
1)
1.8V
≤
Vcc
≤
2.5V(Note
1)
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
AC CHARACTERISTICS
Param.
Sym.
No.
1
F
CLK
Characteristic
Clock Frequency
2
T
CSS
CS Setup Time
3
T
CSH
CS Hold Time
4
5
T
CSD
Tsu
CS Disable Time
Data Setup Time
6
T
HD
Data Hold Time
7
8
9
T
R
T
F
T
HI
CLK Rise Time
CLK Fall Time
Clock High Time
10
T
LO
Clock Low Time
11
12
13
T
CLD
T
CLE
T
V
Clock Delay Time
Clock Enable Time
Output Valid from Clock
Low
Output Hold Time
Output Disable Time
14
15
T
HO
T
DIS
16
T
HS
HOLD Setup Time
Note 1:
This parameter is periodically sampled and not 100% tested.
2:
T
WC
begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is
complete.
3:
This parameter is not tested but ensured by characterization. For endurance estimates in a specific
application, please consult the Total Endurance™ Model which can be obtained from our web site:
www.microchip.com.
2003 Microchip Technology Inc.
Preliminary
DS21822C-page 3
25AA256/25LC256
TABLE 1-2:
AC CHARACTERISTICS (CONTINUED)
Industrial (I):
T
A
= -40°C to +85°C
Automotive (E): T
A
= -40°C to +125°C
Min.
20
40
80
30
60
160
30
60
160
—
1M
Max.
—
—
—
—
—
—
—
—
—
5
—
Units
ns
ns
ns
ns
ns
ns
ns
ns
ns
ms
V
CC
= 1.8V to 5.5V
V
CC
= 2.5V to 5.5V
Test Conditions
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
4.5V
≤
Vcc
≤
5.5V(Note
1)
2.5V
≤
Vcc
<
4.5V(Note
1)
1.8V
≤
Vcc
<
2.5V(Note
1)
4.5V
≤
Vcc
≤
5.5V
2.5V
≤
Vcc
<
4.5V
1.8V
≤
Vcc
<
2.5V
(N
OTE
2)
AC CHARACTERISTICS
Param.
Sym.
No.
17
T
HH
Characteristic
HOLD Hold Time
18
T
HZ
HOLD Low to Output
High-Z
HOLD High to Output
Valid
Internal Write Cycle Time
Endurance
19
T
HV
20
21
T
WC
—
E/W
(N
OTE
3)
Cycles
Note 1:
This parameter is periodically sampled and not 100% tested.
2:
T
WC
begins on the rising edge of CS after a valid write sequence and ends when the internal write cycle is
complete.
3:
This parameter is not tested but ensured by characterization. For endurance estimates in a specific
application, please consult the Total Endurance™ Model which can be obtained from our web site:
www.microchip.com.
TABLE 1-3:
AC Waveform:
V
LO
= 0.2V
AC TEST CONDITIONS
—
(Note 1)
(Note 2)
—
0.5 V
CC
0.5 V
CC
V
HI
= V
CC
- 0.2V
V
HI
= 4.0V
C
L
= 100 pF
Timing Measurement Reference Level
Input
Output
Note 1:
For V
CC
≤
4.0V
2:
For Vcc > 4.0V
DS21822C-page 4
Preliminary
2003 Microchip Technology Inc.
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