AT24C01D/AT24C02D
I²C-Compatible (Two-Wire) Serial EEPROM
1Kbit (128 x 8), 2Kbit (256 x 8)
Features
Low-Voltage Operation:
VCC = 1.7V to 3.6V
Internally Organized as 128 x 8 (1K) or 256 x 8 (2K)
Industrial Temperature Range: -40°C to +85°C
I2C-Compatible (Two-Wire) Serial Interface:
100 kHz Standard mode, 1.7V to 3.6V
400 kHz Fast mode, 1.7V to 3.6V
1 MHz Fast Mode Plus (FM+), 2.5V to 3.6V
Schmitt Triggers, Filtered Inputs for Noise Suppression
Bidirectional Data Transfer Protocol
Write-Protect Pin for Full Array Hardware Data Protection
Ultra Low Active Current (1 mA maximum) and Standby Current (0.8 μA maximum)
8-Byte Page Write Mode:
Partial page writes allowed
Random and Sequential Read Modes
Self-Timed Write Cycle within 5 ms Maximum
ESD Protection > 4,000V
High Reliability:
Endurance: 1,000,000 write cycles
Data retention: 100 years
Green Package Options (Lead-free/Halide-free/RoHS compliant)
Die Sale Options: Wafer Form and Bumped Wafers
Packages
8-Lead PDIP(1), 8-Lead SOIC, 5-Lead SOT23, 8-Lead TSSOP, 8-Pad UDFN and 8-Ball VFBGA
Note: 
1. Contact Microchip Sales for the availability of this package.
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 1
Table of Contents
Features.......................................................................................................................... 1
Packages.........................................................................................................................1
1. Package Types (not to scale).................................................................................... 4
2. Pin Descriptions.........................................................................................................5
2.1. Device Address Inputs (A0, A1, A2).............................................................................................5
2.2. Ground......................................................................................................................................... 5
2.3. Serial Data (SDA).........................................................................................................................5
2.4. Serial Clock (SCL)........................................................................................................................6
2.5. Write-Protect (WP)....................................................................................................................... 6
2.6. Device Power Supply................................................................................................................... 6
3. Description.................................................................................................................7
3.1. System Configuration Using Two-Wire Serial EEPROMs ........................................................... 7
3.2. Block Diagram.............................................................................................................................. 8
4. Electrical Characteristics........................................................................................... 9
4.1. Absolute Maximum Ratings..........................................................................................................9
4.2. DC and AC Operating Range.......................................................................................................9
4.3. DC Characteristics....................................................................................................................... 9
4.4. AC Characteristics......................................................................................................................10
4.5. Electrical Specifications..............................................................................................................12
5. Device Operation and Communication....................................................................14
5.1. Clock and Data Transition Requirements...................................................................................14
5.2. Start and Stop Conditions.......................................................................................................... 14
5.3. Acknowledge and No-Acknowledge...........................................................................................15
5.4. Standby Mode............................................................................................................................ 15
5.5. Software Reset...........................................................................................................................16
6. Memory Organization.............................................................................................. 17
6.1. Device Addressing..................................................................................................................... 17
7. Write Operations......................................................................................................19
7.1. Byte Write...................................................................................................................................19
7.2. Page Write..................................................................................................................................19
7.3. Acknowledge Polling.................................................................................................................. 20
7.4. Write Cycle Timing..................................................................................................................... 20
7.5. Write Protection..........................................................................................................................21
8. Read Operations..................................................................................................... 23
8.1. Current Address Read................................................................................................................23
8.2. Random Read............................................................................................................................ 23
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 2
8.3. Sequential Read.........................................................................................................................24
9. Device Default Condition from Microchip................................................................ 25
10. Packaging Information.............................................................................................26
10.1. Package Marking Information.....................................................................................................26
11. Revision History.......................................................................................................41
The Microchip Web Site................................................................................................ 42
Customer Change Notification Service..........................................................................42
Customer Support......................................................................................................... 42
Product Identification System........................................................................................43
Microchip Devices Code Protection Feature................................................................. 44
Legal Notice...................................................................................................................44
Trademarks................................................................................................................... 44
Quality Management System Certified by DNV.............................................................45
Worldwide Sales and Service........................................................................................46
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 3
1. Package Types (not to scale)
A0
A1
A2
GND
Vcc
WP
SCL
SDA
8-pad UDFN
(Top View)
8-lead PDIP/SOIC/TSSOP
(Top View)
A0 1
2
3
4
8
7
6
5
A1
A2
GND
Vcc
WP
SCL
SDA
1
2
3
4
8
7
6
5
A0
A1
A2
GND
Vcc
WP
SCL
SDA
8-ball VFBGA
(Top View)
5-lead SOT23(1)
(Top View)
SCL 1
2
3
5
4
GND
SDA
WP
Vcc
1
2
3
4 5
6
7
8
Note: 
1. Refer to Device Addressing for details about addressing the SOT23 version of the device.
AT24C01D/AT24C02D
Package Types (not to scale)
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 4
2. Pin Descriptions
The descriptions of the pins are listed in Table 2-1.
Table 2-1. Pin Function Table
Name 8-Lead
PDIP
8-Lead
SOIC
8-Lead
TSSOP
5-Lead
SOT23
8-Pad
UDFN(1)
8-Ball
VFBGA
Function
A0(2)1 1 1 1 1 Device Address Input
A1(2)2 2 2 2 2 Device Address Input
A2(2)3 3 3 3 3 Device Address Input
GND 4 4 4 2 4 4 Ground
SDA 5 5 5 3 5 5 Serial Data
SCL 6 6 6 1 6 6 Serial Clock
WP(2)7 7 7 5 7 7 Write-Protect
VCC 8 8 8 4 8 8 Device Power Supply
Note: 
1. The exposed pad on the this package can be connected to GND or left floating.
2. If the A0, A1, A2 or WP pins are not driven, they are internally pulled down to GND. In order to
operate in a wide variety of application environments, the pull-down mechanism is intentionally
designed to be somewhat strong. Once these pins are biased above the CMOS input buffer’s trip
point (~0.5 x VCC), the pulldown mechanism disengages. Microchip recommends connecting these
pins to a known state whenever possible.
2.1 Device Address Inputs (A0, A1, A2)
The A0, A1 and A2 pins are device address inputs that are hard-wired (directly to GND or to VCC) for
compatibility with other two-wire Serial EEPROM devices. When the pins are hard-wired, as many as
eight devices may be addressed on a single bus system. A device is selected when a corresponding
hardware and software match is true. If these pins are left floating, the A0, A1 and A2 pins will be
internally pulled down to GND. However, due to capacitive coupling that may appear in customer
applications, Microchip recommends always connecting the address pins to a known state. When using a
pullup resistor, Microchip recommends using 10 kΩ or less.
2.2 Ground
The ground reference for the power supply. GND should be connected to the system ground.
2.3 Serial Data (SDA)
The SDA pin is an open-drain bidirectional input/output pin used to serially transfer data to and from the
device. The SDA pin must be pulled high using an external pull-up resistor (not to exceed 10 kΩ in value)
and may be wire-ORed with any number of other open-drain or open-collector pins from other devices on
the same bus.
AT24C01D/AT24C02D
Pin Descriptions
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 5
2.4 Serial Clock (SCL)
The SCL pin is used to provide a clock to the device and to control the flow of data to and from the
device. Command and input data present on the SDA pin is always latched in on the rising edge of SCL,
while output data on the SDA pin is clocked out on the falling edge of SCL. The SCL pin must either be
forced high when the serial bus is idle or pulled high using an external pull-up resistor.
2.5 Write-Protect (WP)
The write-protect input, when connected to GND, allows normal write operations. When the WP pin is
connected directly to VCC, all write operations to the protected memory are inhibited.
If the pin is left floating, the WP pin will be internally pulled down to GND. However, due to capacitive
coupling that may appear in customer applications, Microchip recommends always connecting the WP
pin to a known state. When using a pullup resistor, Microchip recommends using 10 kΩ or less.
Table 2-2. Write-Protect
WP Pin Status Part of the Array Protected
At VCC Full Array
At GND Normal Write Operations
2.6 Device Power Supply
The VCC pin is used to supply the source voltage to the device. Operations at invalid VCC voltages may
produce spurious results and should not be attempted.
AT24C01D/AT24C02D
Pin Descriptions
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 6
3. Description
The AT24C01D/AT24C02D provides 1,024/2,048 bits of Serial Electrically Erasable and Programmable
Read-Only Memory (EEPROM) organized as 128/256 words of 8 bits each. The device’s cascading
feature allows up to eight devices to share a common twowire bus. This device is optimized for use in
many industrial and commercial applications where low-power and low-voltage operations are essential.
The device is available in space-saving 8-lead SOIC, 8-lead TSSOP, 8-pad UDFN, 8-lead PDIP(1), 5-lead
SOT23 and 8-ball VFBGA packages. All packages operate from 1.7V to 3.6V.
Note: 
1. Contact Microchip Sales for the availability of this package.
3.1 System Configuration Using Two-Wire Serial EEPROMs
I2C Bus Master:
Microcontroller
Slave 0
AT24CXXX
VCC
WP
SDA
SCL
A0
A1
A2
GND
VCC
GND
SCL
SDA
WP
RPUP(max) = tR(max)
0.8473 x CL
RPUP(min) = VCC - VOL(max)
IOL
Slave 1
AT24CXXX
VCC
WP
SDA
SCL
A0
A1
A2
GND
Slave 7
AT24CXXX
VCC
WP
SDA
SCL
A0
A1
A2
GND
VCC
AT24C01D/AT24C02D
Description
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 7
3.2 Block Diagram
1 page
Start
Stop
Detector
GND
A2
Memory
System Control
Module
High Voltage
Generation Circuit
Data & ACK
Input/Output Control
Address Register
and Counter
Write
Protection
Control
DOUT
DIN
Hardware
Address
Comparator
VCC
WP
SCL
SDA
Power
On Reset
Generator
EEPROM Array
Column Decoder
Row Decoder
Data Register
A1
A0
AT24C01D/AT24C02D
Description
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 8
4. Electrical Characteristics
4.1 Absolute Maximum Ratings
Temperature under bias -55°C to +125°C
Storage temperature -65°C to +150°C
VCC 4.1V
Voltage on any pin with respect to ground -0.6V to +4.1V
DC output current 5.0 mA
ESD protection > 4 kV
Note:  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 these or any other
conditions above those indicated in the operation listings of this specification is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
4.2 DC and AC Operating Range
Table 4-1. DC and AC Operating Range
AT24C01D/AT24C02D
Operating Temperature (Case) Industrial Temperature Range -40°C to +85°C
VCC Power Supply Low Voltage Grade 1.7V to 3.6V
4.3 DC Characteristics
Table 4-2. DC Characteristics
Parameter Symbol Minimum Typical(1)Maximum Units Test Conditions
Supply
Voltage
VCC 1.7 3.6 V
Supply
Current
ICC1 0.08 0.3 mA VCC = 1.8V(2), Read at
400 kHz
0.15 0.5 mA VCC = 3.6V, Read at 1 MHz
Supply
Current
ICC2 0.20 1.0 mA VCC = 3.6V, Write at 1 MHz
Standby
Current
ISB 0.08 0.4 μA VCC = 1.8V(2), VIN = VCC or
GND
0.10 0.8 μA VCC = 3.6V, VIN = VCC or
GND
AT24C01D/AT24C02D
Electrical Characteristics
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 9
...........continued
Parameter Symbol Minimum Typical(1)Maximum Units Test Conditions
Input
Leakage
Current
ILI 0.10 3.0 μA VIN = VCC or GND
Output
Leakage
Current
ILO 0.05 3.0 μA VOUT = VCC or GND
Input Low
Level
VIL -0.6 VCC x 0.3 V Note 2
Input High
Level
VIH VCC x 0.7 VCC + 0.5 V Note 2
Output Low
Level
VOL1 0.2 V VCC = 1.7V, IOL = 0.15 mA
Output Low
Level
VOL2 0.4 V VCC = 3.0V, IOL = 2.1 mA
Note: 
1. Typical values characterized at TA = +25°C unless otherwise noted.
2. This parameter is characterized but is not 100% tested in production.
4.4 AC Characteristics
Table 4-3. AC Characteristics(1)
Parameter Symbol Standard Mode Fast Mode Fast Mode Plus Units
VCC = 1.7V to 3.6V VCC = 1.7V to 3.6V VCC = 2.5V to 3.6V
Min. Max. Min. Max. Min. Max.
Clock
Frequency,
SCL
fSCL 100 400 1000 kHz
Clock Pulse
Width Low
tLOW 4,700 1,300 500 ns
Clock Pulse
Width High
tHIGH 4,000 600 400 ns
Input Filter
Spike
Suppression
(SCL,SDA)(2)
tI 100 100 100 ns
Clock Low to
Data Out Valid
tAA 4,500 900 450 ns
Bus Free Time
between Stop
and Start(2)
tBUF 4,700 1,300 500 ns
AT24C01D/AT24C02D
Electrical Characteristics
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 10
...........continued
Parameter Symbol Standard Mode Fast Mode Fast Mode Plus Units
VCC = 1.7V to 3.6V VCC = 1.7V to 3.6V VCC = 2.5V to 3.6V
Min. Max. Min. Max. Min. Max.
Start Hold
Time
tHD.STA 4,000 600 250 ns
Start Set-up
Time
tSU.STA 4,700 600 250 ns
Data In Hold
Time
tHD.DAT 0 0 0 ns
Data In Set-up
Time
tSU.DAT 200 100 100 ns
Inputs Rise
Time(2)
tR 1,000 300 100 ns
Inputs Fall
Time(2)
tF 300 300 100 ns
Stop Set-up
Time
tSU.STO 4,700 600 250 ns
Write-Protect
Setup Time
tSU.WP 4,000 600 100 ns
Write-Protect
Hold Time
tHD.WP 4,000 600 400 ns
Data Out Hold
Time
tDH 100 50 50 ns
Write Cycle
Time
tWR 5 5 5 ms
Note: 
1. AC measurement conditions:
CL: 100 pF
RPUP (SDA bus line pull-up resistor to VCC): 1.3 kΩ (1000 kHz), 4 kΩ (400 kHz),
10 kΩ (100 kHz)
Input pulse voltages: 0.3 x VCC to 0.7 x VCC
Input rise and fall times: ≤50 ns
Input and output timing reference voltages: 0.5 x VCC
2. These parameters are determined through product characterization and are not 100% tested in
production.
AT24C01D/AT24C02D
Electrical Characteristics
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 11
Figure 4-1.  Bus Timing
SCL
SDA In
SDA Out
tF
tHIGH
tLOW
tR
tDH
tAA tBUF
tSU.STO
tSU.DAT
tHD.DAT
tHD.STA
tSU.STA
4.5 Electrical Specifications
4.5.1 Power-Up Requirements and Reset Behavior
During a power-up sequence, the VCC supplied to the AT24C01D/AT24C02D should monotonically rise
from GND to the minimum VCC level, as specified in Table 4-1, with a slew rate no faster than 0.1 V/µs.
4.5.1.1 Device Reset
To prevent inadvertent write operations or any other spurious events from occurring during a power-up
sequence, the AT24C01D/AT24C02D includes a Power-on Reset (POR) circuit. Upon power-up, the
device will not respond to any commands until the VCC level crosses the internal voltage threshold (VPOR)
that brings the device out of Reset and into Standby mode.
The system designer must ensure the instructions are not sent to the device until the VCC supply has
reached a stable value greater than or equal to the minimum VCC level. Additionally, once the VCC is
greater than or equal to the minimum VCC level, the bus master must wait at least tPUP before sending the
first command to the device. See Table 4-4 for the values associated with these power-up parameters.
Table 4-4. Power-up Conditions(1)
Symbol Parameter Min. Max. Units
tPUP Time required after VCC is stable before the device can accept commands 100 µs
VPOR Power-on Reset Threshold Voltage 1.5 V
tPOFF Minimum time at VCC = 0V between power cycles 1 ms
Note: 
1. These parameters are characterized but they are not 100% tested in production.
If an event occurs in the system where the VCC level supplied to the AT24C01D/AT24C02D drops below
the maximum VPOR level specified, it is recommended that a full power cycle sequence be performed by
first driving the VCC pin to GND, waiting at least the minimum tPOFF time and then performing a new
power-up sequence in compliance with the requirements defined in this section.
AT24C01D/AT24C02D
Electrical Characteristics
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 12
4.5.2 Pin Capacitance
Table 4-5. Pin Capacitance(1)
Symbol Test Condition Max. Units Conditions
CI/O Input/Output Capacitance (SDA) 8 pF VI/O = 0V
CIN Input Capacitance (A0, A1, A2 and SCL) 6 pF VIN = 0V
Note: 
1. This parameter is characterized but is not 100% tested in production.
4.5.3 EEPROM Cell Performance Characteristics
Table 4-6. EEPROM Cell Performance Characteristics
Operation Test Condition Min. Max. Units
Write Endurance(1)TA = 25°C, VCC(min.) < VCC < VCC(max.),
Byte or Page Write mode
1,000,000 Write Cycles
Data Retention(1)TA = 55°C 100 Years
Note: 
1. Performance is determined through characterization and the qualification process.
AT24C01D/AT24C02D
Electrical Characteristics
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 13
5. Device Operation and Communication
The AT24C01D/AT24C02D operates as a slave device and utilizes a simple I2C-compatible two-wire
digital serial interface to communicate with a host controller, commonly referred to as the bus master. The
master initiates and controls all read and write operations to the slave devices on the serial bus, and both
the master and the slave devices can transmit and receive data on the bus.
The serial interface is comprised of just two signal lines: Serial Clock (SCL) and Serial Data (SDA).
The SCL pin is used to receive the clock signal from the master, while the bidirectional SDA pin is used to
receive command and data information from the master as well as to send data back to the master.
Data is always latched into the AT24C01D/AT24C02D on the rising edge of SCL and always output from
the device on the falling edge of SCL. Both the SCL and SDA pin incorporate integrated spike
suppression filters and Schmitt Triggers to minimize the effects of input spikes and bus noise.
All command and data information is transferred with the Most Significant bit (MSb) first. During bus
communication, one data bit is transmitted every clock cycle, and after eight bits (one byte) of data have
been transferred, the receiving device must respond with either an Acknowledge (ACK) or a
No-Acknowledge (NACK) response bit during a ninth clock cycle (ACK/NACK clock cycle) generated by
the master. Therefore, nine clock cycles are required for every one byte of data transferred. There are no
unused clock cycles during any read or write operation, so there must not be any interruptions or breaks
in the data stream during each data byte transfer and ACK or NACK clock cycle.
During data transfers, data on the SDA pin must only change while SCL is low, and the data must remain
stable while SCL is high. If data on the SDA pin changes while SCL is high, then either a Start or a Stop
condition will occur. Start and Stop conditions are used to initiate and end all serial bus communication
between the master and the slave devices. The number of data bytes transferred between a Start and a
Stop condition is not limited and is determined by the master. In order for the serial bus to be idle, both
the SCL and SDA pins must be in the logic-high state at the same time.
5.1 Clock and Data Transition Requirements
The SDA pin is an open-drain terminal and therefore must be pulled high with an external pullup resistor.
SCL is an input pin that can either be driven high or pulled high using an external pullup resistor. Data on
the SDA pin may change only during SCL low time periods. Data changes during SCL high periods will
indicate a Start or Stop condition as defined below. The relationship of the AC timing parameters with
respect to SCL and SDA for the AT24C01D/AT24C02D are shown in the timing waveform in Figure 4-1.
The AC timing characteristics and specifications are outlined in AC Characteristics.
5.2 Start and Stop Conditions
5.2.1 Start Condition
A Start condition occurs when there is a high-to-low transition on the SDA pin while the SCL pin is at a
stable logic ‘1’ state and will bring the device out of Standby mode. The master uses a Start condition to
initiate any data transfer sequence; therefore, every command must begin with a Start condition.
The device will continuously monitor the SDA and SCL pins for a Start condition but will not respond
unless one is detected. Refer to Figure 5-1 for more details.
5.2.2 Stop Condition
A Stop condition occurs when there is a low-to-high transition on the SDA pin while the SCL pin is stable
in the logic ‘1’ state.
AT24C01D/AT24C02D
Device Operation and Communication
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 14
The master can use the Stop condition to end a data transfer sequence with the AT24C01D/AT24C02D,
which will subsequently return to Standby mode. The master can also utilize a repeated Start condition
instead of a Stop condition to end the current data transfer if the master will perform another operation.
Refer to Figure 5-1 for more details.
5.3 Acknowledge and No-Acknowledge
After every byte of data is received, the receiving device must confirm to the transmitting device that it
has successfully received the data byte by responding with what is known as an Acknowledge (ACK).
An ACK is accomplished by the transmitting device first releasing the SDA line at the falling edge of the
eighth clock cycle followed by the receiving device responding with a logic ‘0’ during the entire high period
of the ninth clock cycle.
When the AT24C01D/AT24C02D is transmitting data to the master, the master can indicate that it is done
receiving data and wants to end the operation by sending a logic ‘1’ response to the AT24C01D/
AT24C02D instead of an ACK response during the ninth clock cycle. This is known as a No-Acknowledge
(NACK) and is accomplished by the master sending a logic ‘1’ during the ninth clock cycle, at which point
the AT24C01D/AT24C02D will release the SDA line so the master can then generate a Stop condition.
The transmitting device, which can be the bus master or the Serial EEPROM, must release the SDA line
at the falling edge of the eighth clock cycle to allow the receiving device to drive the SDA line to a logic ‘0
to ACK the previous 8-bit word. The receiving device must release the SDA line at the end of the ninth
clock cycle to allow the transmitter to continue sending new data. A timing diagram has been provided in
Figure 5-1 to better illustrate these requirements.
Figure 5-1. Start Condition, Data Transitions, Stop Condition and Acknowledge
SCL
SDA
SDA
Must Be
Stable
SDA
Change
Allowed
SDA
Change
Allowed
Acknowledge
Valid
Stop
Condition
Start
Condition
1 2 8 9
SDA
Must Be
Stable Acknowledge Window
The transmitting device (Master or Slave)
must release the SDA line at this point to allow
the receiving device (Master or Slave) to drive the
SDA line low to ACK the previous 8-bit word.
The receiver (Master or Slave)
must release the SDA line at
this point to allow the transmitter
to continue sending new data.
5.4 Standby Mode
The AT24C01D/AT24C02D features a low-power Standby mode that is enabled when any one of the
following occurs:
A valid power-up sequence is performed (see Power-Up Requirements and Reset Behavior).
A Stop condition is received by the device unless it initiates an internal write cycle (see Write
Operations).
At the completion of an internal write cycle (see Write Operations).
AT24C01D/AT24C02D
Device Operation and Communication
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 15
An unsuccessful match of the device type identifier or hardware address in the device address byte
occurs (see Device Addressing).
The bus master does not ACK the receipt of data read out from the device; instead it sends a
NACK response (see Read Operations).
5.5 Software Reset
After an interruption in protocol, power loss or system Reset, any twowire device can be protocol reset
by clocking SCL until SDA is released by the EEPROM and goes high. The number of clock cycles until
SDA is released by the EEPROM will vary. The software Reset sequence should not take more than nine
dummy clock cycles. Once the software Reset sequence is complete, new protocol can be sent to the
device by sending a Start condition followed by the protocol. Refer to Figure 5-2 for an illustration.
Figure 5-2. Software Reset
SCL 9
Device is
8321
SDA
Dummy Clock Cycles
SDA Released
Software Reset
by EEPROM
In the event that the device is still non-responsive or remains active on the SDA bus, a power cycle must
be used to reset the device (see Power-Up Requirements and Reset Behavior).
AT24C01D/AT24C02D
Device Operation and Communication
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 16
6. Memory Organization
The AT24C01D is internally organized as 16 pages of 8 bytes each. The AT24C02D is internally
organized as 32 pages of 8 bytes each.
6.1 Device Addressing
Accessing the device requires an 8-bit device address byte following a Start condition to enable the
device for a read or write operation. Since multiple slave devices can reside on the serial bus, each slave
device must have its own unique address so the master can access each device independently.
The Most Significant four bits of the device address byte is referred to as the device type identifier. The
device type identifier ‘1010’ (Ah) is required in bits 7 through 4 of the device address byte (see
Table 61).
Following the 4-bit device type identifier are the hardware slave address bits, A2, A1 and A0. These bits
can be used to expand the address space by allowing up to eight Serial EEPROM devices on the same
bus. These hardware slave address bits must correlate with the voltage level on the corresponding
hardwired device address input pins A0, A1 and A2. The A0, A1 and A2 pins use an internal proprietary
circuit that automatically biases the pin to a logic ‘0’ state if the pin is allowed to float. In order to operate
in a wide variety of application environments, the pulldown mechanism is intentionally designed to be
somewhat strong. Once the pin is biased above the CMOS input buffer’s trip point (~0.5 x VCC), the pull-
down mechanism disengages. Microchip recommends connecting the A0, A1 and A2 pins to a known
state whenever possible.
When using the SOT23 package, the A2, A1 and A0 pins are not accessible and are left floating. The
previously mentioned automatic pulldown circuit will set this pin to a logic ‘0’ state. As a result, to
properly communicate with the device in the SOT23 package, the A2, A1 and A0 software bits must
always be set to logic ‘0’ for any operation. Refer to Table 6-1 to review these bit positions.
The eighth bit (bit 0) of the device address byte is the Read/Write Select bit. A read operation is initiated if
this bit is high and a write operation is initiated if this bit is low.
Upon the successful comparison of the device address byte, the AT24C01D/AT24C02D will return an
ACK. If a valid comparison is not made, the device will NACK.
Table 6-1. Device Address Byte
Package Device Type Identifier Hardware Slave Address Bits R/W Select
Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
SOIC, TSSOP, UDFN, PDIP,
VFBGA
1 0 1 0 A2 A1 A0 R/W
SOT23 1 0 1 0 0 0 0 R/W
For all operations except the current address read, a word address byte must be transmitted to the device
immediately following the device address byte. The word address byte contain a 7-bit (in the case of the
AT24C01D) or 8-bit (in the case of the AT24C02D) memory array word address, and is used to specify
which byte location in the EEPROM to start reading or writing. Refer to Table 6-2 to review these bit
positions.
AT24C01D/AT24C02D
Memory Organization
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 17
Table 6-2. Word Address Byte
Device Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0
AT24C01D X(1)A6 A5 A4 A3 A2 A1 A0
AT24C02D A7 A6 A5 A4 A3 A2 A1 A0
Note: 
1. Bit 7 is a “don't care” bit on the AT24C01D.
AT24C01D/AT24C02D
Memory Organization
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 18
7. Write Operations
All write operations for the AT24C01D/AT24C02D begin with the master sending a Start condition,
followed by a device address byte with the R/W bit set to logic ‘0’, and then by the word address byte.
The data value(s) to be written to the device immediately follow the word address byte.
7.1 Byte Write
The AT24C01D/AT24C02D supports the writing of a single 8-bit byte. Selecting a data word in the
AT24C01D requires a 7-bit word address, while selecting a data word in the AT24C02D requires an 8-bit
word address.
Upon receipt of the proper device address and the word address bytes, the EEPROM will send an
Acknowledge. The device will then be ready to receive the 8-bit data word. Following receipt of the 8bit
data word, the EEPROM will respond with an ACK. The addressing device, such as a bus master, must
then terminate the write operation with a Stop condition. At that time, the EEPROM will enter an internally
self-timed write cycle, which will be completed within tWR, while the data word is being programmed into
the nonvolatile EEPROM. All inputs are disabled during this write cycle, and the EEPROM will not
respond until the write is complete.
Figure 7-1. Byte Write
SCL
SDA
Device Address Byte Word Address Byte Data Word
Start
by
Master
ACK
from
Slave
MSB MSB
Stop
by
Master
MSB
1 2 3 4 5 6 7 8 9
1 0 1 0 A2 A1 A0 0 0
1 2 3 4 5 6 7 8 9
D7 D6 D5 D4 D3 D2 D1 D0 0
A7 A6 A5 A4 A3 A2 A1 A0 0
1 2 3 4 5 6 7 8 9
ACK
from
Slave
ACK
from
Slave
7.2 Page Write
A page write operation allows up to 8 bytes to be written in the same write cycle, provided all bytes are in
the same row of the memory array (where address bits A7 to A3 are the same). Partial page writes of less
than 8 bytes are also allowed.
A page write is initiated the same way as a byte write, but the bus master 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 bus master can transmit up to seven additional data words. The EEPROM will respond with an
ACK after each data word is received. Once all data to be written has been sent to the device, the bus
master must issue a Stop condition (see Figure 7-2) at which time the internally self-timed write cycle will
begin.
The lower three bits of the word address are internally incremented following the receipt of each data
word. The higher order address bits are not incremented and retain the memory page row location. Page
write operations are limited to writing bytes within a single physical page, regardless of the number of
bytes actually being written. When the incremented word address reaches the page boundary, the
address counter will roll-over to the beginning of the same page. Nevertheless, creating a rollover event
should be avoided as previously loaded data in the page could become unintentionally altered.
AT24C01D/AT24C02D
Write Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 19
Figure 7-2.  Page Write
SCL
SDA
Start
by
Master
ACK
from
Slave
ACK
from
Slave
Device Address Byte Word Address Byte
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 1 0 A2 A1 A0 0 0
ACK
from
Slave
Stop
by
Master
ACK
from
Slave
Data Word (n) Data Word (n+x), max of 8 without rollover
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
MSB MSB
A7 A6 A5 A4 A3 A2 A1 A0 0
D7 D6 D5 D4 D3 D2 D1 D0 0 D7 D6 D5 D4 D3 D2 D1 D0 0
7.3 Acknowledge Polling
An Acknowledge Polling routine can be implemented to optimize time-sensitive applications that would
prefer not to wait the fixed maximum write cycle time (tWR). This method allows the application to know
immediately when the Serial EEPROM write cycle has completed, so a subsequent operation can be
started.
Once the internally self-timed write cycle has started, an Acknowledge Polling routine can be initiated.
This involves repeatedly sending a Start condition followed by a valid device address byte with the R/W
bit set at logic ‘0’. The device will not respond with an ACK while the write cycle is ongoing. Once the
internal write cycle has completed, the EEPROM will respond with an ACK, allowing a new read or write
operation to be immediately initiated. A flowchart has been included below in Figure 7-3 to better illustrate
this technique.
Figure 7-3. Acknowledge Polling Flowchart
7.4 Write Cycle Timing
The length of the self-timed write cycle (tWR) is defined as the amount of time from the Stop condition that
begins the internal write cycle to the Start condition of the first device address byte sent to the
AT24C01D/AT24C02D that it subsequently responds to with an ACK. Figure 7-4 has been included to
AT24C01D/AT24C02D
Write Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 20
show this measurement. During the internally self-timed write cycle, any attempts to read from or write to
the memory array will not be processed.
Figure 7-4. Write Cycle Timing
tWR
Stop
Condition
Start
Condition
Data Word n
ACKD0
SDA
Stop
Condition
SCL 8 9
ACK
First Acknowledge from the device
to a valid device address sequence after
write cycle is initiated. The minimum tWR
can only be determined through
the use of an ACK Polling routine.
9
7.5 Write Protection
The AT24C01D/AT24C02D utilizes a hardware data protection scheme that allows the user to
writeprotect the entire memory contents when the WP pin is at VCC (or a valid VIH). No write protection
will be set if the WP pin is at GND or left floating.
Table 7-1. AT24C01D/AT24C02D Write-Protect Behavior
WP Pin Voltage Part of the Array Protected
VCC Full Array
GND None Write Protection Not Enabled
The status of the WP pin is sampled at the Stop condition for every byte write or page write operation
prior to the start of an internally selftimed write cycle. Changing the WP pin state after the Stop condition
has been sent will not alter or interrupt the execution of the write cycle. The WP pin state must be valid
with respect to the associated setup (tSU.WP) and hold (tHD.WP) timing as shown in Figure 7-5 below. The
WP setup time is the amount of time that the WP state must be stable before the Stop condition is issued.
The WP hold time is the amount of time after the Stop condition that the WP pin must remain stable.
If an attempt is made to write to the device while the WP pin has been asserted, the device will
acknowledge the device address, word address and data bytes, but no write cycle will occur when the
Stop condition is issued. The device will immediately be ready to accept a new read or write command.
AT24C01D/AT24C02D
Write Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 21
Figure 7-5. Write-Protect Setup and Hold Timing
SCL
SDA IN
1 2 7 8 9
D7 D6 D1 D0
WP
tSU.WP
Stop Condition
by Master
Data Word Input Sequence Page/Byte Write Operation
ACK by Slave
tHD.WP
AT24C01D/AT24C02D
Write Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 22
8. 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 byte must be a logic ‘1’. There are three read operations:
Current Address Read
Random Address Read
Sequential Read
8.1 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 VCC is
maintained to the part. The address roll-over during a read is from the last byte of the last page to the first
byte of the first page of the memory.
A current address read operation will output data according to the location of the internal data word
address counter. This is initiated with a Start condition, followed by a valid device address byte with the
R/W bit set to logic ‘1’. The device will ACK this sequence and the current address data word is serially
clocked out on the SDA line. All types of read operations will be terminated if the bus master does not
respond with an ACK (it NACKs) during the ninth clock cycle. After the NACK response, the master may
send a Stop condition to complete the protocol, or it can send a Start condition to begin the next
sequence.
Figure 8-1. Current Address Read
SCL
SDA
Device Address Byte Data Word (n)
Start
by
Master
ACK
from
Slave
NACK
from
Master
Stop
by
Master
MSB MSB
1 0 1 0 A2 A1 A0 1 0 D7 D6 D5 D4 D3 D2 D1 D0 1
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
8.2 Random Read
A random read begins in the same way as a byte write operation does to load in a new data word
address. This is known as a “dummy write” sequence; however, the data byte and the Stop condition of
the byte write must be omitted to prevent the part from entering an internal write cycle. Once the device
address and word address are clocked in and acknowledged by the EEPROM, the bus master must
generate another Start condition. The bus master now initiates a current address read by sending a Start
condition, followed by a valid device address byte with the R/W bit set to logic ‘1’. The EEPROM will ACK
the device address and serially clock out the data word on the SDA line. All types of read operations will
be terminated if the bus master does not respond with an ACK (it NACKs) during the ninth clock cycle.
After the NACK response, the master may send a Stop condition to complete the protocol, or it can send
a Start condition to begin the next sequence.
AT24C01D/AT24C02D
Read Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 23
Figure 8-2. Random Read
SCL
SDA
Start
by
Master
Device Address Byte Word Address Byte
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 1 0 A2 A1 A0 0 0
Dummy Write
Start
by
Master
Device Address Byte Data Word (n)
Stop
by
Master
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 1 0 A2 A1 A0 1 0 D7 D6 D5 D4 D3 D2 D1 D0 1
A7 A6 A5 A4 A3 A2 A1 A0 0
ACK
from
Slave
ACK
from
Slave
ACK
from
Slave
NACK
from
Master
8.3 Sequential Read
Sequential reads are initiated by either a current address read or a random read. After the bus master
receives a data word, it responds with an Acknowledge. As long as the EEPROM receives an ACK, it will
continue to increment the word address and serially clock out sequential data words. When the maximum
memory address is reached, the data word address will roll-over and the sequential read will continue
from the beginning of the memory array. All types of read operations will be terminated if the bus master
does not respond with an ACK (it NACKs) during the ninth clock cycle. After the NACK response, the
master may send a Stop condition to complete the protocol, or it can send a Start condition to begin the
next sequence.
Figure 8-3. Sequential Read
SCL
SDA
Start
by
Master
ACK
from
Slave
ACK
from
Master
Device Address Byte Data Word (n)
MSB MSB
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
1 0 1 0 A2 A1 A0 1 0 D7 D6 D5 D4 D3 D2 D1 D0 0
ACK
from
Master
NACK
from
Master
Stop
by
Master
ACK
from
Master
Data Word (n+1) Data Word (n+2) Data Word (n+x)
1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9 1 2 3 4 5 6 7 8 9
D7 D6 D5 D4 D3 D2 D1 D0 0 D7 D6 D5 D4 D3 D2 D1 D0 0 D7 D6 D5 D4 D3 D2 D1 D0 1
MSB MSB MSB
AT24C01D/AT24C02D
Read Operations
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 24
9. Device Default Condition from Microchip
The AT24C01D/AT24C02D is delivered with the EEPROM array set to logic ‘1’, resulting in FFh data in all
locations.
AT24C01D/AT24C02D
Device Default Condition from Microchip
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 25
10. Packaging Information
10.1 Package Marking Information
AT24C01D and AT24C02D: Package Marking Information
Catalog Number Truncation
AT24C01D Truncation Code ###: 01D / ##: 1D
AT24C02D Truncation Code ###: 02D / ##: 2D
Date Codes Voltages
YY = Year Y = Year WW = Work Week of Assembly % = Minimum Voltage
16: 2016 20: 2020 6: 2016 0: 2020 02: Week 2 M: 1.7V min
17: 2017 21: 2021 7: 2017 1: 2021 04: Week 4
18: 2018 22: 2022 8: 2018 2: 2022 ...
19: 2019 23: 2023 9: 2019 3: 2023 52: Week 52
Country of Origin Device Grade Atmel Truncation
CO = Country of Origin H or U: Industrial Grade AT: Atmel
ATM: Atmel
ATML: Atmel
Trace Code
NNN = Alphanumeric Trace Code (2 Characters for Small Packages)
Note 2: Package drawings are not to scale
Note 1: designates pin 1
Note 3: For SOT23 package with date codes before 7B, the bottom line (YMXX) is marked on the bottom side and there is no Country of Assembly (
@
) mark on the top line.
YYWWNNN
###% CO
ATMLHYWW
8-lead SOIC 8-lead TSSOP
YYWWNNN
###%CO
ATHYWW
8-pad UDFN
###
H%
NNN
2.0 x 3.0 mm Body
8-lead PDIP
YYWWNNN
###% CO
ATMLUYWW
5-lead SOT23
##%UYY
WWNNN
8-ball VFBGA
1.5 x 2.0 mm Body
###U
WNNN
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 26
© 2017 Microchip Technology Incorporated
B
A
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
Microchip Technology Drawing No. C04-018D Sheet 1 of 2
8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP]
eB
E
A
A1
A2
L
8X b
8X b1
D
E1
c
C
PLANE
.010 C
12
N
NOTE 1
TOP VIEW
END VIEWSIDE VIEW
e
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 27
© 2017 Microchip Technology Incorporated
Microchip Technology Drawing No. C04-018D Sheet 2 of 2
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP]
Units INCHES
Dimension Limits MIN NOM MAX
Number of Pins N 8
Pitch e.100 BSC
Top to Seating Plane A - - .210
Molded Package Thickness A2 .115 .130 .195
Base to Seating Plane A1 .015
Shoulder to Shoulder Width E .290 .310 .325
Molded Package Width E1 .240 .250 .280
Overall Length D .348 .365 .400
Tip to Seating Plane L .115 .130 .150
Lead Thickness c.008 .010 .015
Upper Lead Width b1 .040 .060 .070
Lower Lead Width b.014 .018 .022
Overall Row Spacing eB - - .430
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
3.
1.
protrusions shall not exceed .010" per side.
2.
4.
Notes:
§
--
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or
Pin 1 visual index feature may vary, but must be located within the hatched area.
§ Significant Characteristic
Dimensioning and tolerancing per ASME Y14.5M
e
DATUM A DATUM A
e
b
e
2
b
e
2
ALTERNATE LEAD DESIGN
(VENDOR DEPENDENT)
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 28
© 2017 Microchip Technology Incorporated
0.25 CA–B D
C
SEATING
PLANE
TOP VIEW
SIDE VIEW
VIEW A–A
0.10 C
0.10 C
Microchip Technology Drawing No. C04-057-SN Rev D Sheet 1 of 2
8X
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC]
12
N
h
h
A1
A2
A
A
B
e
D
E
E
2
E1
2
E1
NOTE 5
NOTE 5
NX b
0.10 CA–B
2X
H0.23
(L1)
L
R0.13
R0.13
VIEW C
SEE VIEW C
NOTE 1
D
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 29
© 2017 Microchip Technology Incorporated
Microchip Technology Drawing No. C04-057-SN Rev D Sheet 2 of 2
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC]
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
Foot Angle -
15°-
Mold Draft Angle Bottom
15°-
Mold Draft Angle Top
0.51-0.31
b
Lead Width
0.25-0.17
c
Lead Thickness
1.27-0.40LFoot Length
0.50-0.25hChamfer (Optional)
4.90 BSCDOverall Length
3.90 BSCE1Molded Package Width
6.00 BSCEOverall Width
0.25-0.10
A1
Standoff
--1.25A2Molded Package Thickness
1.75--AOverall Height
1.27 BSC
e
Pitch
8NNumber of Pins
MAXNOMMINDimension Limits
MILLIMETERSUnits
protrusions shall not exceed 0.15mm per side.
3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or
REF: Reference Dimension, usually without tolerance, for information purposes only.
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
1. Pin 1 visual index feature may vary, but must be located within the hatched area.
2. § Significant Characteristic
4. Dimensioning and tolerancing per ASME Y14.5M
Notes:
§
Footprint L1 1.04 REF
5. Datums A & B to be determined at Datum H.
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 30
© 2017 Microchip Technology Incorporated
RECOMMENDED LAND PATTERN
Microchip Technology Drawing C04-2057-SN Rev B
8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm Body [SOIC]
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
Notes:
Dimensioning and tolerancing per ASME Y14.5M1.
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
Dimension Limits
Units
CContact Pad Spacing
Contact Pitch
MILLIMETERS
1.27 BSC
MIN
E
MAX
5.40
Contact Pad Length (X8)
Contact Pad Width (X8)
Y1
X1
1.55
0.60
NOM
E
X1
C
Y1
SILK SCREEN
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 31
© 2017 Microchip Technology Incorporated
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D
N
E
E1
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12
b
e
c
A
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A2
L1 L
φ
0LFURFKLS 7HFKQRORJ\ 'UDZLQJ &%
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 32
© 2017 Microchip Technology Incorporated
Note: For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 33
0.15 C D
2X
NOTE 1 1 2
N
TOP VIEW
SIDE VIEW
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
0.20 C
C
SEATING PLANE
AA2
A1
e
NX bB
0.20 C A-B D
e1
D
E1
E1/2
E/2
E
D
A
0.20 C 2X
(DATUM D)
(DATUM A-B)
A
A
SEE SHEET 2
0.20 C
© 2018 Microchip Technology Inc.
Microchip Technology Drawing C04-21344 Rev B Sheet 1 of 2
5-Lead Plastic Thin Small Outline Transistor (NMB) [TSOT]
Atmel Legacy Global Package Code TSZ
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 34
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
(c)
L
L1
θ
VIEW A-A
SHEET 1
protrusions shall not exceed 0.25mm per side.
1.
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
2.
Foot Angle
Number of Leads
Pitch
Outside lead pitch
Overall Height
Molded Package Thickness
Standoff
Overall Width
Molded Package Width
Overall Length
Foot Length
Footprint
Lead Thickness
Lead Width
Notes:
L1
θ
b
c
Dimension Limits
E
E1
D
L
e1
A
A2
A1
Units
N
e
0.08
0.30 -
-
-
0.20
0.50
MILLIMETERS
0.95 BSC
1.90 BSC
0.30
-
0.70
-
0.60 REF
2.90 BSC
-
2.80 BSC
1.60 BSC
0.90
-
-
MIN
5
NOM
1.10
1.00
0.10
0.60
MAX
REF: Reference Dimension, usually without tolerance, for information purposes only.
Dimensions D and E1 do not include mold flash or protrusions. Mold flash or
Dimensioning and tolerancing per ASME Y14.5M
© 2018 Microchip Technology Inc.
Microchip Technology Drawing C04-21344 Rev B Sheet 2 of 2
5-Lead Plastic Thin Small Outline Transistor (NMB) [TSOT]
Atmel Legacy Global Package Code TSZ
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 35
RECOMMENDED LAND PATTERN
Dimension Limits
Units
Contact Pitch
MILLIMETERS
0.95 BSC
MIN
E
MAX
Contact Pad Length (X5)
Contact Pad Width (X5)
Y1
X1
1.05
0.60
NOM
SILK SCREEN
1 2
5
C
E
X1
Y1
G
CContact Pad Spacing 2.60
Contact Pad to Center Pad (X2) G 0.20
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
Notes:
Dimensioning and tolerancing per ASME Y14.5M
For best soldering results, thermal vias, if used, should be filled or tented to avoid solder loss during
reflow process
1.
2.
For the most current package drawings, please see the Microchip Packaging Specification located at
http://www.microchip.com/packaging
Note:
© 2018 Microchip Technology Inc.
Microchip Technology Drawing C04-23344 Rev B
5-Lead Plastic Thin Small Outline Transistor (NMB) [TSOT]
Atmel Legacy Global Package Code TSZ
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 36
B
A
0.10 C
0.10 C
(DATUM B)
(DATUM A)
C
SEATING
PLANE
12
N
2X TOP VIEW
SIDE VIEW
NOTE 1
12
N
0.10 C A B
0.10 C A B
0.10 C
0.08 C
Microchip Technology Drawing C04-21355-Q4B Rev A Sheet 1 of 2
2X
8X
For the most current package drawings, please see the Microchip Packaging Specification locate d a t
http://www.microchip.com/packaging
Note:
8-Lead Ultra Thin Plastic Dual Flat, No Lead Packag e (Q4B) - 2x3 mm Body [UDFN]
Atmel Legacy YNZ Package
© 2017 Microchip Technology Inc.
D
E
D2
E2 K
L8X b
e
e
2
0.10 C A B
0.05 C
A
(A3)
A1
BOTTOM VIEW
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 37
REF: Reference Dimension, usually without tolerance, for information purposes only.
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
1.
2.
3.
Notes:
Pin 1 visual index feature may vary, but must be located within the hatched area.
Package is saw singulated
Dimensioning and tolerancing per ASME Y14.5M
For the most current package drawings, please see the Microchip Packaging Specification locate d a t
http://www.microchip.com/packaging
Note:
© 2017 Microchip Technology Inc.
Number of Terminals
Overall He ig ht
Terminal Width
Overall Width
Terminal Length
Exposed Pad Width
Terminal Thickness
Pitch
Standoff
Units
Dimension Limit s
A1
A
b
E2
A3
e
L
E
N0.50 BSC
0.152 REF
1.20
0.35
0.18
0.50
0.00
0.25
0.40
1.30
0.55
0.02
3.00 BSC
MILLIMETERS
MIN NOM
8
1.40
0.45
0.30
0.60
0.05
MAX
K-0.20 -Terminal-to-Exposed-Pad
Overall Length
Exposed Pad Length D
D2 1.40 2.00 BSC
1.50 1.60
Microchip Technology Drawing C04-21355-Q4B Rev A Sheet 2 of 2
8-Lead Ultra Thin Plastic Dual Flat, No Lead Packag e (Q4B) - 2x3 mm Body [UDFN]
Atmel Legacy YNZ Package
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 38
RECOMMENDED LAND PATTERN
Dimension Limit s
Units
Optional Center Pad Width
Optional Center Pad Length
Contact Pitch
Y2
X2 1.40
1.60
MILLIMETERS
0.50 BSC
MIN
EMAX
Contact Pad Length (X8)
Contact Pad Width (X8 ) Y1
X1 0.85
0.30
NOM
12
8
CContact Pad Spacing 2.90
Contact Pad to Center Pad (X8) G1 0.20
Thermal Via Diamete r V
Thermal Via Pitch EV 0.30
1.00
BSC: Basic Dimension. Theoretically exact value shown without tolerances.
Notes:
Dimensioning and tolerancing per ASME Y14.5M
For best soldering results, thermal vias, if used, should be filled or ten t ed to a v o i d solder lo ss during
reflow process
1.
2.
For the most current package drawings, please see the Microchip Packaging Specification locate d a t
http://www.microchip.com/packaging
Note:
© 2017 Microchip Technology Inc.
Microchip Technolo gy Drawing C04-21 35 5-Q4 B Re v A
8-Lead Ultra Thin Plastic Dual Flat, No Lead Packag e (Q4B) - 2x3 mm Body [UDFN]
Atmel Legacy YNZ Package
X2
Y2
Y1
SILK SCREEN X1
E
C
EV
G2
G1
ØV
Cont act Pad to Contact Pad (X6) G2 0.33
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 39
DRAWING NO. REV. TITLE GPC
8U3-1 G
7/1/14
8U3-1, 8-ball, 1.50mm x 2.00mm body, 0.50mm pitch,
Very Thin, Fine-Pitch Ball Grid Array Package (VFBGA) GXU
COMMON DIMENSIONS
(Unit of Measure - mm)
SYMBOL MIN NOM MAX NOTE
A
0.73 0.79 0.85
A1 0.09 0.14 0.19
A2 0.40 0.45 0.50
b 0.20 0.25 0.30 2
D
1.50 BSC
E
2.0 BSC
e
0.50 BSC
e1 0.25 REF
d
1.00 BSC
d1 0.25 REF
1. This drawing is for general information only.
2. Dimension ‘b’ is measured at maximum solder ball diameter.
3. Solder ball composition shall be 95.5Sn-4.0Ag-.5Cu.
Notes:
A2
SIDE VIEW
A
PIN 1 BALL PAD CORNER
TOP VIEW
E
D
A1
b
8 SOLDER BALLS
BOTTOM VIEW
(d1)
d
4
3
2
(e1)
6
e
5
7
PIN 1 BALL PAD CORNER
1
8
2.
(4X)d0.10
B
d0.08 C
C
f0.10 C
j n 0.15 mC A B
j n 0.08mC
A
Note:  For the most current package drawings, please see the Microchip Packaging Specification located
at http://www.microchip.com/packaging.
AT24C01D/AT24C02D
Packaging Information
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 40
11. Revision History
Revision A (November 2018)
Updated to the Microchip template. Microchip DS20006100 replaces Atmel document 8871. Updated Part
Marking Information. Updated the "Software Reset" section. Added ESD rating. Removed lead finish
designation. Updated trace code format in package markings. Updated section content throughout for
clarification. Updated the 8U3-1 VFBGA package drawing. Updated the PDIP, SOIC, TSSOP, SOT23 and
UDFN package drawings to Microchip format.
Atmel Document 8871 Revision F (January 2017)
Updated Power On Requirements and Reset Behavior section.
Atmel Document 8871 Revision E (December 2016)
Removed AT24C02D-SSHMHY-T part number from datasheet. Removed Product variation code from
Ordering Code Detail.
Part marking SOT23:
Moved backside mark (YMXX) to front side line2.
Added @ = Country of Assembly
Atmel Document 8871 Revision D (October 2015)
Added AT24C02D-SSHMHY-T ordering code option and updated the 8S1 package drawing.
Atmel Document 8871 Revision C (January 2015)
Added 100 kHz timing set for reference, the UDFN extended quantity option, and the figure for “System
Configuration Using 2-Wire Serial EEPROMs”. Updated 8X, 8MA2, and 8P3 package outline drawings
and the ordering information.
Atmel Document 8871 Revision B (March 2014)
Corrected pinouts from bottom to top view and grammatical changes. No changes to functional
specification.
Atmel Document 8871 Revision A (December 2013)
Initial release of this document.
AT24C01D/AT24C02D
Revision History
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 41
The Microchip Web Site
Microchip provides online support via our web site at http://www.microchip.com/. This web site is used as
a means to make files and information easily available to customers. Accessible by using your favorite
Internet browser, the web site contains the following information:
Product Support – Data sheets and errata, application notes and sample programs, design
resources, users guides and hardware support documents, latest software releases and archived
software
General Technical Support – Frequently Asked Questions (FAQ), technical support requests,
online discussion groups, Microchip consultant program member listing
Business of Microchip – Product selector and ordering guides, latest Microchip press releases,
listing of seminars and events, listings of Microchip sales offices, distributors and factory
representatives
Customer Change Notification Service
Microchip’s customer notification service helps keep customers current on Microchip products.
Subscribers will receive e-mail notification whenever there are changes, updates, revisions or errata
related to a specified product family or development tool of interest.
To register, access the Microchip web site at http://www.microchip.com/. Under “Support”, click on
“Customer Change Notification” and follow the registration instructions.
Customer Support
Users of Microchip products can receive assistance through several channels:
Distributor or Representative
Local Sales Office
Field Application Engineer (FAE)
Technical Support
Customers should contact their distributor, representative or Field Application Engineer (FAE) for support.
Local sales offices are also available to help customers. A listing of sales offices and locations is included
in the back of this document.
Technical support is available through the web site at: http://www.microchip.com/support
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 42
Product Identification System
To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office.
Product Family
24C = Standard I2C-compatible
Serial EEPROM
Device Density
Shipping Carrier Option
Device Grade or
Wafer/Die Thickness
Package Option
01 = 1 Kilobit
02 = 2 Kilobit
T = Tape and Reel, Standard Quantity Option
E = Tape and Reel, Extended Quantity Option
B = Bulk (Tubes)
Operating Voltage
M = 1.7V to 3.6V
H or U = Industrial Temperature Range
(-40°C to +85°C)
11 = 11mil Wafer Thickness
SS = SOIC
X = TSSOP
MA = 2.0mm x 3.0mm UDFN
P = PDIP
ST = SOT23
C = VFBGA
WWU = Wafer Unsawn
AT24C01D-SSHM-T
Device Revision
Examples
Device Package Package
Drawing
Code
Package
Option
Shipping Carrier Option Device Grade
AT24C01DPUM PDIP P P Bulk (Tubes) Industrial
Temperature
(-40°C to 85°C)
AT24C01DSSHMB SOIC SN SS Bulk (Tubes)
AT24C01DSSHMT SOIC SN SS Tape and Reel
AT24C02DSSHMT SOIC SN SS Tape and Reel
AT24C01DXHMB TSSOP ST X Bulk (Tubes)
AT24C02DXHMT TSSOP ST X Tape and Reel
AT24C01DMAHMT UDFN Q4B MA Tape and Reel
AT24C01DMAHME UDFN Q4B MA Extended Qty. Tape and
Reel
AT24C02DMAHME UDFN Q4B MA Extended Qty. Tape and
Reel
AT24C02DSTUMT SOT23 NMB ST Tape and Reel
AT24C02DCUMT VFBGA 8U3-1 C Tape and Reel
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 43
Microchip Devices Code Protection Feature
Note the following details of the code protection feature on Microchip devices:
Microchip products meet the specification contained in their particular Microchip Data Sheet.
Microchip believes that its family of products is one of the most secure families of its kind on the
market today, when used in the intended manner and under normal conditions.
There are dishonest and possibly illegal methods used to breach the code protection feature. All of
these methods, to our knowledge, require using the Microchip products in a manner outside the
operating specifications contained in Microchip’s Data Sheets. Most likely, the person doing so is
engaged in theft of intellectual property.
Microchip is willing to work with the customer who is concerned about the integrity of their code.
Neither Microchip nor any other semiconductor manufacturer can guarantee the security of their
code. Code protection does not mean that we are guaranteeing the product as “unbreakable.”
Code protection is constantly evolving. We at Microchip are committed to continuously improving the
code protection features of our products. Attempts to break Microchip’s code protection feature may be a
violation of the Digital Millennium Copyright Act. If such acts allow unauthorized access to your software
or other copyrighted work, you may have a right to sue for relief under that Act.
Legal Notice
Information contained in this publication regarding device applications and the like is provided only for
your convenience and may be superseded by updates. It is your responsibility to ensure that your
application meets with your specifications. MICROCHIP MAKES NO REPRESENTATIONS OR
WARRANTIES OF ANY KIND WHETHER EXPRESS OR IMPLIED, WRITTEN OR ORAL, STATUTORY
OR OTHERWISE, RELATED TO THE INFORMATION, INCLUDING BUT NOT LIMITED TO ITS
CONDITION, QUALITY, PERFORMANCE, MERCHANTABILITY OR FITNESS FOR PURPOSE.
Microchip disclaims all liability arising from this information and its use. Use of Microchip devices in life
support and/or safety applications is entirely at the buyers risk, and the buyer agrees to defend,
indemnify and hold harmless Microchip from any and all damages, claims, suits, or expenses resulting
from such use. No licenses are conveyed, implicitly or otherwise, under any Microchip intellectual
property rights unless otherwise stated.
Trademarks
The Microchip name and logo, the Microchip logo, AnyRate, AVR, AVR logo, AVR Freaks, BitCloud,
chipKIT, chipKIT logo, CryptoMemory, CryptoRF, dsPIC, FlashFlex, flexPWR, Heldo, JukeBlox, KeeLoq,
Kleer, LANCheck, LINK MD, maXStylus, maXTouch, MediaLB, megaAVR, MOST, MOST logo, MPLAB,
OptoLyzer, PIC, picoPower, PICSTART, PIC32 logo, Prochip Designer, QTouch, SAM-BA, SpyNIC, SST,
SST Logo, SuperFlash, tinyAVR, UNI/O, and XMEGA are registered trademarks of Microchip Technology
Incorporated in the U.S.A. and other countries.
ClockWorks, The Embedded Control Solutions Company, EtherSynch, Hyper Speed Control, HyperLight
Load, IntelliMOS, mTouch, Precision Edge, and Quiet-Wire are registered trademarks of Microchip
Technology Incorporated in the U.S.A.
Adjacent Key Suppression, AKS, Analog-for-the-Digital Age, Any Capacitor, AnyIn, AnyOut, BodyCom,
CodeGuard, CryptoAuthentication, CryptoAutomotive, CryptoCompanion, CryptoController, dsPICDEM,
dsPICDEM.net, Dynamic Average Matching, DAM, ECAN, EtherGREEN, In-Circuit Serial Programming,
ICSP, INICnet, Inter-Chip Connectivity, JitterBlocker, KleerNet, KleerNet logo, memBrain, Mindi, MiWi,
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 44
motorBench, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, MultiTRAK, NetDetach, Omniscient
Code Generation, PICDEM, PICDEM.net, PICkit, PICtail, PowerSmart, PureSilicon, QMatrix, REAL ICE,
Ripple Blocker, SAM-ICE, Serial Quad I/O, SMART-I.S., SQI, SuperSwitcher, SuperSwitcher II, Total
Endurance, TSHARC, USBCheck, VariSense, ViewSpan, WiperLock, Wireless DNA, and ZENA are
trademarks of Microchip Technology Incorporated in the U.S.A. and other countries.
SQTP is a service mark of Microchip Technology Incorporated in the U.S.A.
Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries.
GestIC is a registered trademark of Microchip Technology Germany II GmbH & Co. KG, a subsidiary of
Microchip Technology Inc., in other countries.
All other trademarks mentioned herein are property of their respective companies.
© 2018, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved.
ISBN: 978-1-5224-3849-6
Quality Management System Certified by DNV
ISO/TS 16949
Microchip received ISO/TS-16949:2009 certification for its worldwide headquarters, design and wafer
fabrication facilities in Chandler and Tempe, Arizona; Gresham, Oregon and design centers in California
and India. The Company’s quality system processes and procedures are for its PIC® MCUs and dsPIC®
DSCs, KEELOQ® code hopping devices, Serial EEPROMs, microperipherals, nonvolatile memory and
analog products. In addition, Microchip’s quality system for the design and manufacture of development
systems is ISO 9001:2000 certified.
AT24C01D/AT24C02D
© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 45
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© 2018 Microchip Technology Inc. Datasheet DS20006100A-page 46