ATMEL AT24CS128W-10SI 2-wire serial eeproms with permanent software write protect Datasheet

Features
• One-Time Programmable (OTP) Feature
• Low-Voltage and Standard-Voltage Operation
•
•
•
•
•
•
•
•
•
•
•
– 5.0 (VCC = 4.5V to 5.5V)
– 2.7 (VCC = 2.7V to 5.5V)
– 1.8 (VCC = 1.8V to 3.6V)
Internally Organized 16,384 x 8 and 32,768 x 8
2-Wire Serial Interface
Schmitt Trigger, Filtered Inputs for Noise Suppression
Bidirectional Data Transfer Protocol
1 MHz (5V), 400 kHz (2.7V) and 100 kHz (1.8V) Compatibility
Write Protect Pin for Hardware and Software Data Protection
64-Byte Page Write Mode (Partial Page Writes Allowed)
Self-Timed Write Cycle (5 ms typical)
High Reliability
– Endurance: 100,000 Write Cycles
– Data Retention: 40 Years
– ESD Protection: >4000V
Automotive Grade and Extended Temperature Devices Available
8-Pin JEDEC PDIP and 8-Pin JEDEC and EIAJ SOIC Packages
2-Wire Serial
EEPROMs
with Permanent
Software Write
Protect
Description
128K (16,384 x 8)
The AT24CS128/256 provides 131,072/262,144 bits of serial electrically erasable and
programmable read only memory (EEPROM) organized as 16,384/32,768 words of 8
bits each. The device’s cascadable feature allows up to 4 devices to share a common
2-wire bus. The device also features a one-time programmable 2048 bit array, which
once enabled, becomes read-only and cannot be overwritten. If not enabled, the OTP
section will function as part of the normal memory array. The device is optimized for
use in many industrial and commercial applications where low power and low voltage
operation are essential. The devices are available in space-saving 8-pin JEDEC PDIP
(AT24CS128/256), 8-pin EIAJ (AT24CS128/256), 8-pin JEDEC SOIC (AT24CS128)
packages. In addition, the entire family is available in 5.0V (4.5V to 5.5V), 2.7V (2.7V
to 5.5V) and 1.8V (1.8V to 3.6V) versions.
Pin Configurations
Pin Name
Function
A0 to A2
Address Inputs
SDA
Serial Data
SCL
Serial Clock Input
WP
Write Protect
8-Pin PDIP
A0
A1
A2
GND
1
2
3
4
8
7
6
5
VCC
WP
SCL
SDA
256K (32,768 x 8)
AT24CS128
AT24CS256
with Permanent
Software Write
Protect
Advanced
Information
8-Pin SOIC
A0
A1
A2
GND
1
2
3
4
8
7
6
5
VCC
WP
SCL
SDA
Rev. 1152A–09/98
1
Absolute Maximum Ratings*
Operating Temperature .................................. -55°C to +125°C
Storage Temperature ..................................... -65°C to +150°C
Voltage on Any Pin
with Respect to Ground .....................................-1.0V to +7.0V
Maximum Operating Voltage........................................... 6.25V
*NOTICE:
Stresses beyond 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 these or any
other conditions beyond those indicated in the
operational sections of this specification is not
implied. Exposure to absolute maximum rating
conditions for extended periods may affect device
reliability.
DC Output Current........................................................ 5.0 mA
Block Diagram
A2
Pin Description
SERIAL CLOCK (SCL): The SCL input is used to positive
edge clock data into each EEPROM device and negative
edge clock data out of each device.
SERIAL DATA (SDA): The SDA pin is bidirectional for
serial data transfer. This pin is open-drain driven and may
be wire-ORed with any number of other open-drain or open
collector devices.
DEVICE/PAGE ADDRESSES (A2, A1, A0): The A1 and
A0 pins are device address inputs that are hardwired or left
not connected for hardware compatibility with AT24C32/64.
When the pins are hardwired, as many as four 128K/256K
devices may be addressed on a single bus system (device
addressing is discussed in detail under the Device
Addressing section). When the pins are not hardwired, the
2
AT24CS128/256
default A1 and A0 are zero. The A2 device address input is
a “don’t care” input.
WRITE PROTECT (WP): The write protect input, when tied
to GND, allows normal write operations. When WP is tied
high to VCC, all write operations to the memory are inhibited. If left unconnected, WP is internally pulled down to
GND. Switching WP to VCC prior to a write operation creates a software write protect function.
Memory Organization
AT24CS128/256, 128K/256K SERIAL EEPROM: The
128K/256K is internally organized as 256/512 pages of 64bytes each. Random word addressing requires a 14/15-bit
data word address.
AT24CS128/256
Pin Capacitance(1)
Applicable over recommended operating range from TA = 25°C, f = 1.0 MHz, VCC = +1.8V.
Symbol
Test Condition
Max
Units
Conditions
CI/O
Input/Output Capacitance (SDA)
8
pF
VI/O = 0V
CIN
Input Capacitance (A0, A1, SCL)
6
pF
VIN = 0V
Note:
This parameter is characterized and is not 100% tested.
DC Characteristics
Applicable over recommended operating range from: TAI = -40°C to +85°C, VCC = +1.8V to +5.5V, TAC = 0°C to +70°C,
VCC = +1.8V to +5.5V (unless otherwise noted).
Symbol
Parameter
VCC1
Supply Voltage
VCC2
Test Condition
Max
Units
1.8
3.6
V
Supply Voltage
2.7
5.5
V
VCC3
Supply Voltage
4.5
5.5
V
ICC1
Supply Current
VCC = 5.0V
READ at 400 kHz
1.0
2.0
mA
ICC2
Supply Current
VCC = 5.0V
WRITE at 400 kHz
2.0
3.0
mA
Standby Current
(1.8V option)
VCC = 1.8V
0.2
ISB1
µA
ISB2
Standby Current
(2.7V option)
ISB3
Standby Current
(5.0V option)
ILI
Input Leakage Current
VIN = VCC or VSS
ILO
Output Leakage Current
VOUT = VCC or VSS
VCC = 3.6V
VCC = 2.7V
VCC = 5.5V
VCC = 4.5 - 5.5V
Min
Typ
VIN = VCC or VSS
2.0
0.5
VIN = VCC or VSS
5.0
5.0
µA
0.10
3.0
µA
0.05
3.0
µA
-0.6
VCC x 0.3
V
VCC x 0.7
VCC + 0.5
V
VIN = VCC or VSS
(Note:)
µA
VIL
Input Low Level
VIH
Input High Level(Note:)
VOL2
Output Low Level
VCC = 3.0V
IOL = 2.1 mA
0.4
V
VOL1
Output Low Level
VCC = 1.8V
IOL = 0.15 mA
0.2
V
Note:
VIL min and VIH max are reference only and are not tested
3
AC Characteristics
Applicable over recommended operating range from TA = -40°C to +85°C, VCC = +1.8V to +5.5V, CL = 100 pF (unless otherwise noted). Test conditions are listed in Note 2.
1.8-volt
Min
Min
Parameter
fSCL
Clock Frequency, SCL
tLOW
Clock Pulse Width Low
1.3
0.6
0.6
µs
tHIGH
Clock Pulse Width High
1.0
0.4
0.4
µs
tAA
Clock Low to Data Out Valid
0.1
tBUF
Time the bus must be free before a new
transmission can start(1)
1.2
0.5
0.5
µs
tHD.STA
Start Hold Time
0.6
0.25
0.25
µs
tSU.STA
Start Set-up Time
0.6
0.25
0.25
µs
tHD.DAT
Data In Hold Time
0
0
0
µs
tSU.DAT
Data In Set-up Time
100
100
100
ns
400
(1)
Inputs Rise Time
(1)
0.9
Max
5.0-volt
Symbol
tR
Max
2.7-volt
Min
1000
0.05
0.55
0.05
Max
Units
1000
kHz
0.55
µs
0.3
0.3
0.3
µs
300
100
100
ns
tF
Inputs Fall Time
tSU.STO
Stop Set-up Time
0.6
0.25
0.25
µs
tDH
Data Out Hold Time
50
50
50
ns
tWR
Write Cycle Time
Endurance(1)
5.0V, 25°C, Page Mode
Notes:
20
100K
10
100K
10
100K
ms
Write
Cycles
1. This parameter is characterized and is not 100% tested.
2. AC measurement conditions:
RL (connects to VCC): 1.3KΩ (2.7V, 5V), 10KΩ (1.8V)
Input pulse voltages: 0.3VCC to 0.7VCC
Input rise and fall times: ≤50ns
Input and output timing reference voltages: 0.5VCC
Device Operation
CLOCK and DATA TRANSITIONS: The SDA pin is normally pulled high with an external device. Data on the SDA
pin may change only during SCL low time periods (refer to
Data Validity timing diagram). Data changes during SCL
high periods will indicate a start or stop condition as defined
below.
START CONDITION: A high-to-low transition of SDA with
SCL high is a start condition which must precede any other
command (refer to Start and Stop Definition timing diagram).
STOP CONDITION: A low-to-high transition of SDA with
SCL high is a stop condition. After a read sequence, the
stop command will place the EEPROM in a standby power
mode (refer to Start and Stop Definition timing diagram).
4
AT24CS128/256
ACKNOWLEDGE: All addresses and data words are serially transmitted to and from the EEPROM in 8-bit words.
The EEPROM sends a zero during the ninth clock cycle to
acknowledge that it has received each word.
STANDBY MODE: The AT24CS128/256 features a low
power standby mode which is enabled: a) upon power-up
and b) after the receipt of the STOP bit and the completion
of any internal operations.
MEMORY RESET: After an interruption in protocol, power
loss or system reset, any 2-wire part can be reset by following these steps: (a) Clock up to 9 cycles, (b) look for SDA
high in each cycle while SCL is high and then (c) create a
start condition as SDA is high.
AT24CS128/256
Bus Timing (SCL: Serial Clock, SDA: Serial Data I/O)
Write Cycle Timing (SCL: Serial Clock, SDA: Serial Data I/O)
SCL
SDA
8th BIT
ACK
WORD n
(1)
tWR
STOP
CONDITION
Note:
1.
START
CONDITION
The write cycle time tWR is the time from a valid stop condition of a write sequence to the end of the internal clear/write
cycle.
5
Data Validity
Start and Stop Definition
Output Acknowledge
6
AT24CS128/256
AT24CS128/256
Device Addressing
The 128K/256K EEPROM requires an 8-bit device address
word following a start condition to enable the chip for a read
or write operation (refer to Figure 1). The device address
word consists of a mandatory one, zero sequence for the
first five most significant bits as shown. This is common to
all 2-wire EEPROM devices.
The 128K/256K uses the two device address bits A1, A0 to
allow as many as four devices on the same bus. These bits
must compare to their corresponding hardwired input pins.
The A1 and A0 pins use an internal proprietary circuit that
biases them to a logic low condition if the pins are allowed
to float.
The eighth bit of the device address is the read/write operation select bit. A read operation is initiated if this bit is high
and a write operation is initiated if this bit is low.
Upon a compare of the device address, the EEPROM will
output a zero. If a compare is not made, the device will
return to a standby state.
DATA SECURITY: The AT24CS128/256 has a hardware
data protection scheme that allows the user to write protect
the whole memory when the WP pin is at VCC.
Write Operations
BYTE WRITE: A write operation requires two 8-bit data
word addresses following the device address word and
acknowledgment. Upon receipt of this address, the
EEPROM will again respond with a zero and then clock in
the first 8-bit data word. Following receipt of the 8-bit data
word, the EEPROM will output a zero. The addressing
device, such as a microcontroller, then must terminate the
write sequence with a stop condition. At this time the
EEPROM enters an internally-timed write cycle, tWR, to the
nonvolatile memory. All inputs are disabled during this write
cycle and the EEPROM will not respond until the write is
complete (refer to Figure 2).
PAGE WRITE: The 128K/256K EEPROM is capable of 64byte page writes.
A page write is initiated the same way as a byte write, but
the microcontroller does not send a stop condition after the
first data word is clocked in. Instead, after the EEPROM
acknowledges receipt of the first data word, the microcontroller can transmit up to 63 more data words. The
EEPROM will respond with a zero after each data word
received. The microcontroller must terminate the page
write sequence with a stop condition (refer to Figure 3).
The data word address lower 6 bits are internally incremented following the receipt of each data word. The higher
data word address bits are not incremented, retaining the
memory page row location. When the word address, internally generated, reaches the page boundary, the following
byte is placed at the beginning of the same page. If more
than 64 data words are transmitted to the EEPROM, the
data word address will “roll over” and previous data will be
overwritten. The address “roll over” during write is from the
last byte of the current page to the first byte of the same
page.
ACKNOWLEDGE POLLING: Once the internally-timed
write cycle has started and the EEPROM inputs are disabled, acknowledge polling can be initiated. This involves
sending a start condition followed by the device address
word. The read/write bit is representative of the operation
desired. Only if the internal write cycle has completed will
the EEPROM respond with a zero, allowing the read or
write sequence to continue.
OTP Description/Operation
The OTP feature provides the user with a 2048-bit (256 x 8)
security section, which once programmed and enabled,
becomes read-only and data cannot be changed or overwritten. The OTP section is located in the upper 2K section
of the memory array in the AT24CS128/256. If not enabled,
the OTP section will function as part of the normal memory
array.
To enable the OTP section:
1. Inputs must be connected:
A2 = Don’t Care, A1 and A0 = VCC or GND
2. Initiate the programming sequence:
START 1010 1100 11xx xxxx xxxx xxxx xxxx xxxx STOP
Once enabled, previously written data cannot be changed.
The status of the OTP section can only be confirmed by initiating a programming sequence to the OTP section and
verifying by a read command. The use of the write protect
(WP) feature can be utilized with or without enabling the
OTP function.
Read Operations
Read operations are initiated the same way as write operations with the exception that the read/write select bit in the
device address word is set to one. There are three read
operations: current address read, random address read
and sequential read.
CURRENT ADDRESS READ: The internal data word
address counter maintains the last address accessed during the last read or write operation, incremented by one.
This address stays valid between operations as long as the
chip power is maintained. The address “roll over” during
read is from the last byte of the last memory page, to the
first byte of the first page.
Once the device address with the read/write select bit set
to one is clocked in and acknowledged by the EEPROM,
the current address data word is serially clocked out. The
microcontroller does not respond with an input zero but
does generate a following stop condition (refer to Figure 4).
7
RANDOM READ: A random read requires a “dummy” byte
write sequence to load in the data word address. Once the
device address word and data word address are clocked in
and acknowledged by the EEPROM, the microcontroller
must generate another start condition. The microcontroller
now initiates a current address read by sending a device
address with the read/write select bit high. The EEPROM
acknowledges the device address and serially clocks out
the data word. The microcontroller does not respond with a
zero but does generate a following stop condition (refer to
Figure 5).
Figure 1. Device Address
Figure 2. Byte Write
Figure 3. Page Write
(* = DON’T CARE bit)
(† = DON’T CARE bit for the 128K)
8
AT24CS128/256
SEQUENTIAL READ: Sequential reads are initiated by
either a current address read or a random address read.
After the microcontroller receives a data word, it responds
with an acknowledge. As long as the EEPROM receives an
acknowledge, it will continue to increment the data word
address and serially clock out sequential data words. When
the memory address limit is reached, the data word
address will “roll over” and the sequential read will continue. The sequential read operation is terminated when
the microcontroller does not respond with a zero but does
generate a following stop condition (refer to Figure 6).
AT24CS128/256
Figure 4. Current Address Read
Figure 5. Random Read
(* = DON’T CARE bit)
(† = DON’T CARE bit for the 128K)
Figure 6. Sequential Read
9
AT24CS128 Ordering Information
tWR (max)
(ms)
ICC (max)
(µ
µA)
ISB (max)
(µ
µA)
fMAX
(kHz)
10
3000
5.0
3000
10
20
Ordering Code
Package
1000
AT24CS128-10PC
AT24CS128N-10SC
AT24CS128W-10SC
8P3
8S1
8S2
Commercial
(0°C to 70°C)
5.0
1000
AT24CS128-10PI
AT24CS128N-10SI
AT24CS128W-10SI
8P3
8S1
8S2
Industrial
(-40°C to 85°C)
1500
0.5
400
AT24CS128-10PC-2.7
AT24CS128N-10SC-2.7
AT24CS128W-10SC-2.7
8P3
8S1
8S2
Commercial
(0°C to 70°C)
1500
0.5
400
AT24CS128-10PI-2.7
AT24CS128N-10SI-2.7
AT24CS128W-10SI-2.7
8P3
8S1
8S2
Industrial
(-40°C to 85°C)
800
0.2
100
AT24CS128-10PC-1.8
AT24CS128N-10SC-1.8
AT24CS128W-10SC-1.8
8P3
8S1
8S2
Commercial
(0°C to 70°C)
800
0.2
100
AT24CS128-10PI-1.8
AT24CS128N-10SI-1.8
AT24CS128W-10SI-1.8
8P3
8S1
8S2
Industrial
(-40°C to 85°C)
Package Type
8P3
8-Lead, 0.300" Wide, Plastic Dual Inline Package (PDIP)
8S1
8-Lead, 0.150" Wide, Plastic Gull Wing Small Outline (JEDEC SOIC)
8S2
8-Lead, 0.200" Wide, Plastic Gull Wing Small Outline (EIAJ SOIC)
Options
Blank
Standard Operation (4.5V to 5.5V)
-2.7
Low-Voltage (2.7V to 5.5V)
-1.8
Low-Voltage (1.8V to 3.6V)
10
AT24CS128/256
Operation Range
AT24CS128/256
AT24CS256 Ordering Information
tWR (max)
(ms)
ICC (max)
(µ
µA)
ISB (max)
(µ
µA)
fMAX
(kHz)
10
3000
5.0
3000
10
20
Ordering Code
Package
Operation Range
1000
AT24CS256-10PC
AT24CS256W-10SC
8P3
8S2
Commercial
(0°C to 70°C)
5.0
1000
AT24CS256-10PI
AT24CS256W-10SI
8P3
8S2
Industrial
(-40°C to 85°C)
1500
0.5
400
AT24CS256-10PC-2.7
AT24CS256W-10SC-2.7
8P3
8S2
Commercial
(0°C to 70°C)
1500
0.5
400
AT24CS256-10PI-2.7
AT24CS256W-10SI-2.7
8P3
8S2
Industrial
(-40°C to 85°C)
800
0.2
100
AT24CS256-10PC-1.8
AT24CS256W-10SC-1.8
8P3
8S2
Commercial
(0°C to 70°C)
800
0.2
100
AT24CS256-10PI-1.8
AT24CS256W-10SI-1.8
8P3
8S2
Industrial
(-40°C to 85°C)
Package Type
8P3
8-Lead, 0.300" Wide, Plastic Dual Inline Package (PDIP)
8S2
8-Lead, 0.200" Wide, Plastic Gull Wing Small Outline (EIAJ SOIC)
Blank
Standard Operation (4.5V to 5.5V)
-2.7
Low-Voltage (2.7V to 5.5V)
-1.8
Low-Voltage (1.8V to 3.6V)
Options
11
AT24CS128/256
Packaging Information
8P3, 8-Lead, 0.300" Wide,
Plastic Dual Inline Package (PDIP)
Dimensions in Inches and (Millimeters)
8S1, 8-Lead, 0.150" Wide,
Plastic Gull Wing Small Outline (JEDEC SOIC)
Dimensions in Inches and (Millimeters)
JEDEC STANDARD MS-001 BA
.020 (.508)
.013 (.330)
.400 (10.16)
.355 (9.02)
PIN
1
.280 (7.11)
.240 (6.10)
.157 (3.99)
.150 (3.81)
PIN 1
.244 (6.20)
.228 (5.79)
.037 (.940)
.027 (.690)
.300 (7.62) REF
.050 (1.27) BSC
.210 (5.33) MAX
.100 (2.54) BSC
.196 (4.98)
.189 (4.80)
SEATING
PLANE
.068 (1.73)
.053 (1.35)
.015 (.380) MIN
.150 (3.81)
.115 (2.92)
.070 (1.78)
.045 (1.14)
.022 (.559)
.014 (.356)
.010 (.254)
.004 (.102)
.325 (8.26)
.300 (7.62)
0
REF
8
0
REF
15
.012 (.305)
.008 (.203)
.430 (10.9) MAX
.010 (.254)
.007 (.203)
.050 (1.27)
.016 (.406)
8S2, 8-Lead, 0.200" Wide,
Plastic Gull Wing Small Outline (EIAJ SOIC)
Dimensions in Inches and (Millimeters)
.020 (.508)
.012 (.305)
.213 (5.41)
.205 (5.21)
PIN 1
.330 (8.38)
.300 (7.62)
.050 (1.27) BSC
.212 (5.38)
.203 (5.16)
.080 (2.03)
.070 (1.78)
.013 (.330)
.004 (.102)
0
REF
8
.010 (.254)
.007 (.178)
.035 (.889)
.020 (.508)
12
Similar pages