AT24C01C-XHM-T

AT24C01C/AT24C02C I²C-Compatible (Two-Wire) Serial EEPROM 1‑Kbit (128 x 8), 2‑Kbit (256 x 8) Features • • • • • • • • • • • • • • • Low-Voltage Operation: – VCC = 1.7V to 5.5V 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 5.5V – 400 kHz Fast mode, 1.7V to 5.5V – 1 MHz Fast Mode Plus (FM+), 2.5V to 5.5V Schmitt Triggers, Filtered Inputs for Noise Suppression Bidirectional Data Transfer Protocol Write-Protect Pin for Full Array Hardware Data Protection Ultra Low Active Current (3 mA maximum) and Standby Current (6 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, 8-Lead SOIC, 5-Lead SOT23, 8-Lead TSSOP, 8-Pad UDFN and 8-Ball VFBGA © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 1 AT24C01C/AT24C02C Table of Contents Features.......................................................................................................................... 1 Packages.........................................................................................................................1 1. Package Types (not to scale).................................................................................... 4 2. Pin Descriptions.........................................................................................................5 2.1. 2.2. 2.3. 2.4. 2.5. 2.6. Device Address Inputs (A0, A1, A2).............................................................................................5 Ground......................................................................................................................................... 5 Serial Data (SDA).........................................................................................................................5 Serial Clock (SCL)........................................................................................................................6 Write-Protect (WP)....................................................................................................................... 6 Device Power Supply................................................................................................................... 6 3. Description.................................................................................................................7 3.1. 3.2. System Configuration Using Two-Wire Serial EEPROMs ........................................................... 7 Block Diagram.............................................................................................................................. 8 4. Electrical Characteristics........................................................................................... 9 4.1. 4.2. 4.3. 4.4. 4.5. Absolute Maximum Ratings..........................................................................................................9 DC and AC Operating Range.......................................................................................................9 DC Characteristics....................................................................................................................... 9 AC Characteristics......................................................................................................................10 Electrical Specifications..............................................................................................................11 5. Device Operation and Communication....................................................................13 5.1. 5.2. 5.3. 5.4. 5.5. Clock and Data Transition Requirements...................................................................................13 Start and Stop Conditions.......................................................................................................... 13 Acknowledge and No-Acknowledge...........................................................................................14 Standby Mode............................................................................................................................ 14 Software Reset...........................................................................................................................15 6. Memory Organization.............................................................................................. 16 6.1. Device Addressing..................................................................................................................... 16 7. Write Operations......................................................................................................18 7.1. 7.2. 7.3. 7.4. 7.5. Byte Write...................................................................................................................................18 Page Write..................................................................................................................................18 Acknowledge Polling.................................................................................................................. 19 Write Cycle Timing..................................................................................................................... 19 Write Protection..........................................................................................................................20 8. Read Operations..................................................................................................... 21 8.1. 8.2. Current Address Read................................................................................................................21 Random Read............................................................................................................................ 21 © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 2 AT24C01C/AT24C02C 8.3. Sequential Read.........................................................................................................................22 9. Device Default Condition from Microchip................................................................ 23 10. Packaging Information.............................................................................................24 10.1. Package Marking Information.....................................................................................................24 11. Revision History.......................................................................................................39 The Microchip Web Site................................................................................................ 41 Customer Change Notification Service..........................................................................41 Customer Support......................................................................................................... 41 Product Identification System........................................................................................ 42 Microchip Devices Code Protection Feature................................................................. 43 Legal Notice...................................................................................................................43 Trademarks................................................................................................................... 43 Quality Management System Certified by DNV.............................................................44 Worldwide Sales and Service........................................................................................45 © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 3 AT24C01C/AT24C02C Package Types (not to scale) 1. Package Types (not to scale) 8-lead PDIP/SOIC/TSSOP (Top View) 5-lead SOT23(1) (Top View) A0 1 8 Vcc A1 2 7 WP SCL 1 A2 3 6 SCL GND 2 GND 4 5 SDA SDA 3 8-pad UDFN (Top View) 5 WP 4 Vcc 8-ball VFBGA (Top View) A0 1 8 Vcc A1 2 7 WP A2 3 6 SCL GND 4 5 SDA A0 1 8 Vcc A1 2 7 WP A2 3 6 SCL GND 4 5 SDA Note:  1. Refer to Device Addressing for details about addressing the SOT23 version of the device. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 4 AT24C01C/AT24C02C Pin Descriptions 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 pull‑down 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 pull‑up 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 5 AT24C01C/AT24C02C Pin Descriptions 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 pull‑up resistor, Microchip recommends using 10 kΩ or less. Table 2-2. Write-Protect 2.6 WP Pin Status Part of the Array Protected At VCC Full Array At GND Normal Write Operations 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 6 AT24C01C/AT24C02C Description 3. Description The AT24C01C/AT24C02C 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 two‑wire 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, 5-lead SOT23 and 8-ball VFBGA packages. All packages operate from 1.7V to 5.5V. 3.1 System Configuration Using Two-Wire Serial EEPROMs VCC RPUP(max) = VCC RPUP(min) = tR(max) 0.8473 x CL VCC - VOL(max) IOL SCL SDA WP I2C Bus Master: Microcontroller A0 VCC A0 VCC A0 VCC A1 Slave 0 WP AT24CXXX SDA A1 Slave 1 WP AT24CXXX SDA A1 Slave 7 WP AT24CXXX SDA A2 GND © 2018 Microchip Technology Inc. GND SCL A2 GND Datasheet SCL A2 GND SCL DS20006111A-page 7 AT24C01C/AT24C02C Description Block Diagram A0 Hardware Address Comparator Memory System Control Module Power On Reset Generator VCC High Voltage Generation Circuit A1 Row Decoder 3.2 EEPROM Array 1 page A2 © 2018 Microchip Technology Inc. WP Address Register and Counter Column Decoder SCL Data Register DOUT GND Write Protection Control Data & ACK Input/Output Control DIN Start Stop Detector SDA Datasheet DS20006111A-page 8 AT24C01C/AT24C02C Electrical Characteristics 4. Electrical Characteristics 4.1 Absolute Maximum Ratings Temperature under bias -55°C to +125°C Storage temperature -65°C to +150°C VCC 6.25V Voltage on any pin with respect to ground -1.0V to +7.0V 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 AT24C01C/AT24C02C 4.3 Operating Temperature (Case) Industrial Temperature Range -40°C to +85°C VCC Power Supply Low Voltage Grade 1.7V to 5.5V DC Characteristics Table 4-2. DC Characteristics Symbol Minimum Typical(1) Maximum Units Supply Voltage VCC 1.7 — 5.5 V Supply Current ICC1 — 0.4 1.0 mA VCC = 5.0V, Read at 400 kHz Supply Current ICC2 — 2.0 3.0 mA VCC = 5.0V, Write at 400 kHz Standby Current ISB — — 1.0 μA VCC = 1.7V, VIN = VCC or GND — — 2.0 μA VCC = 2.5V, VIN = VCC or GND — — 6.0 μA VCC = 5.5V, VIN = VCC or GND Parameter © 2018 Microchip Technology Inc. Datasheet Test Conditions DS20006111A-page 9 AT24C01C/AT24C02C Electrical Characteristics ...........continued 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 Parameter Note:  1. 2. 4.4 Typical values characterized at TA = +25°C unless otherwise noted. This parameter is characterized but is not 100% tested in production. AC Characteristics Table 4-3. AC Characteristics(1) Parameter Symbol Fast Mode Fast Mode Plus VCC = 1.7V to 2.5V VCC = 2.5V to 5.5V Min. Max. Min. Max. Units Clock Frequency, SCL fSCL — 400 — 1000 kHz Clock Pulse Width Low tLOW 1,200 — 500 — ns Clock Pulse Width High tHIGH 600 — 400 — ns tI — 100 — 50 ns Clock Low to Data Out Valid tAA 100 900 50 450 ns Bus Free Time between Stop and Start tBUF 1,200 — 500 — ns Start Hold Time tHD.STA 600 — 250 — ns Start Set-Up Time tSU.STA 600 — 250 — ns Data In Hold Time tHD.DAT 0 — 0 — ns Input Filter Spike Suppression © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 10 AT24C01C/AT24C02C Electrical Characteristics ...........continued Parameter Symbol Fast Mode Fast Mode Plus VCC = 1.7V to 2.5V VCC = 2.5V to 5.5V Units Min. Max. Min. Max. tSU.DAT 100 — 100 — ns tR — 300 — 300 ns tF — 300 — 100 ns tSU.STO 600 — 250 — ns Data Out Hold Time tDH 50 — 50 — ns Write Cycle Time tWR — 5 — 5 ms Data In Set-up Time Inputs Rise Time(2) Inputs Fall Time(2) Stop Set-Up Time 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. Figure 4-1.  Bus Timing tF tHIGH tR tLOW SCL tSU.STA tHD.STA tHD.DAT tSU.DAT tSU.STO SDA In tDH tAA tBUF SDA Out 4.5 Electrical Specifications 4.5.1 Power-Up Requirements and Reset Behavior During a power-up sequence, the VCC supplied to the AT24C01C/AT24C02C 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 11 AT24C01C/AT24C02C Electrical Characteristics 4.5.1.1 Device Reset To prevent inadvertent write operations or any other spurious events from occurring during a power-up sequence, the AT24C01C/AT24C02C 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 VPOR Power-on Reset Threshold Voltage tPOFF Minimum time at VCC = 0V between power cycles 100 － µs － 1.5 V 500 － 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 AT24C01C/AT24C02C 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. 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 Write Endurance(1) TA = 25°C, VCC = 3.3V, Page Write mode Data Retention(1) TA = 55°C Min. Max. Units 1,000,000 — Write Cycles 100 — Years Note:  1. Performance is determined through characterization and the qualification process. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 12 AT24C01C/AT24C02C Device Operation and Communication 5. Device Operation and Communication The AT24C01C/AT24C02C 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 AT24C01C/AT24C02C 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 pull‑up resistor. SCL is an input pin that can either be driven high or pulled high using an external pull‑up 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 AT24C01C/AT24C02C 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 13 AT24C01C/AT24C02C Device Operation and Communication The master can use the Stop condition to end a data transfer sequence with the AT24C01C/AT24C02C, 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 AT24C01C/AT24C02C 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 AT24C01C/ AT24C02C 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 AT24C01C/AT24C02C 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 Must Be Stable SDA Must Be Stable 1 2 Acknowledge Window 8 9 SDA Start Condition 5.4 Acknowledge Valid SDA Change Allowed SDA Change Allowed 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. Stop Condition The receiver (Master or Slave) must release the SDA line at this point to allow the transmitter to continue sending new data. Standby Mode The AT24C01C/AT24C02C 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). © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 14 AT24C01C/AT24C02C Device Operation and Communication 5.5 Software Reset After an interruption in protocol, power loss or system Reset, any two‑wire 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 Dummy Clock Cycles SCL 1 2 3 8 SDA Released by EEPROM 9 Device is Software Reset SDA 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). © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 15 AT24C01C/AT24C02C Memory Organization 6. Memory Organization The AT24C01C is internally organized as 16 pages of 8 bytes each. The AT24C02C 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 6‑1). 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 pull‑down 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 pulldown 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 pull‑down 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 AT24C01C/AT24C02C 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 contains a 7-bit (in the case of the AT24C01C) or 8-bit (in the case of the AT24C02C) 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 16 AT24C01C/AT24C02C Memory Organization Table 6-2. Word Address Byte Device Bit 7 Bit 6 Bit 5 Bit 4 Bit 3 Bit 2 Bit 1 Bit 0 AT24C01C X(1) A6 A5 A4 A3 A2 A1 A0 AT24C02C A7 A6 A5 A4 A3 A2 A1 A0 Note:  1. Bit 7 is a “don't care” bit on the AT24C01C. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 17 AT24C01C/AT24C02C Write Operations 7. Write Operations All write operations for the AT24C01C/AT24C02C 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 AT24C01C/AT24C02C supports the writing of a single 8-bit byte. Selecting a data word in the AT24C01C requires a 7-bit word address, while selecting a data word in the AT24C02C 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 8‑bit 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 1 SCL 2 3 4 5 6 7 8 9 1 2 Device Address Byte SDA 1 0 1 0 A2 4 5 6 7 8 9 1 2 3 A0 0 0 A7 A6 A5 A4 A3 A2 4 5 6 7 8 9 D2 D1 D0 0 Data Word Word Address Byte MSB Start by Master 7.2 A1 3 A1 A0 0 D7 D6 D5 D4 D3 MSB MSB ACK from Slave ACK from Slave ACK from Slave Stop by Master 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 roll‑over event should be avoided as previously loaded data in the page could become unintentionally altered. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 18 AT24C01C/AT24C02C Write Operations Figure 7-2.  Page Write 1 SCL 2 3 4 5 6 7 8 9 1 2 3 Device Address Byte SDA 1 0 1 0 A2 A1 4 5 6 7 8 9 A1 A0 0 Word Address Byte A0 0 A7 0 MSB A6 A5 A4 A3 A2 MSB Start by Master ACK from Slave 1 2 ACK from Slave 3 4 5 6 7 8 9 Data Word (n) D7 D6 D5 D4 D3 1 2 3 4 5 7 8 9 Data Word (n+x), max of 8 without rollover D2 D1 D0 0 MSB D7 D6 D5 D4 D3 D2 D1 D0 0 MSB ACK from Slave 7.3 6 ACK from Slave Stop by Master 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 Send any Write protocol. Send Stop condition to initiate the Write cycle. Send Start condition followed by a valid Device Address byte with R/W = 0. Did the device ACK? YES Proceed to next Read or Write operation. NO 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 AT24C01C/AT24C02C that it subsequently responds to with an ACK. Figure 7-4 has been included to © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 19 AT24C01C/AT24C02C Write Operations 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 SCL 8 9 9 ACK ACK Data Word n SDA D0 tWR Stop Condition 7.5 Start Condition 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. Stop Condition Write Protection The AT24C01C/AT24C02C utilizes a hardware data protection scheme that allows the user to write‑protect 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. AT24C01C/AT24C02C 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 self‑timed 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. 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 20 AT24C01C/AT24C02C Read Operations 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: • • • 8.1 Current Address Read Random Address Read 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 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 1 SCL 2 3 4 5 6 7 8 9 1 2 Device Address Byte SDA 1 MSB Start by Master 8.2 0 1 0 A2 A1 3 4 5 6 7 8 9 D2 D1 D0 1 Data Word (n) A0 1 0 D7 D6 D5 D4 D3 MSB ACK from Slave NACK from Master Stop by Master 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. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 21 AT24C01C/AT24C02C Read Operations Figure 8-2. Random Read 1 SCL 2 3 4 5 6 7 8 9 1 2 3 Device Address Byte SDA 1 0 1 0 5 6 7 8 9 A1 A0 0 Word Address Byte A1 A2 4 A0 0 A7 0 MSB A6 A5 A4 A3 A2 MSB Start by Master ACK from Slave ACK from Slave Dummy Write 1 2 3 4 5 6 7 8 9 1 2 3 0 1 0 A2 A1 A0 1 0 MSB 6 7 8 9 D7 D6 D5 D4 D3 D2 D1 D0 1 MSB Start by Master 8.3 5 Data Word (n) Device Address Byte 1 4 ACK from Slave NACK from Master Stop by Master 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 1 SCL 2 3 4 5 6 7 8 9 1 2 3 Device Address Byte SDA 1 0 1 0 A1 A2 A0 1 6 7 8 9 0 D7 D6 D5 D4 D3 D2 D1 D0 0 MSB Start by Master ACK from Slave 2 3 4 5 6 7 8 9 1 2 Data Word (n+1) D7 5 Data Word (n) MSB 1 4 D6 D5 D4 D3 D2 ACK from Master 3 4 5 6 7 9 1 2 Data Word (n+2) D1 D0 0 MSB D7 D6 D5 D4 D3 D2 3 4 5 6 7 8 9 D1 D0 1 Data Word (n+x) D1 D0 0 MSB D7 D6 D5 D4 D3 D2 MSB ACK from Master © 2018 Microchip Technology Inc. 8 ACK from Master Datasheet NACK from Master Stop by Master DS20006111A-page 22 AT24C01C/AT24C02C Device Default Condition from Microchip 9. Device Default Condition from Microchip The AT24C01C/AT24C02C is delivered with the EEPROM array set to logic ‘1’, resulting in FFh data in all locations. © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 23 AT24C01C/AT24C02C Packaging Information 10. Packaging Information 10.1 Package Marking Information AT24C01C and AT24C02C: Package Marking Information 8-lead TSSOP 8-lead SOIC 8-pad UDFN 2.0 x 3.0 mm Body ### H% NNN ATHYWW ###%CO ATMLHYWW ###% CO YYWWNNN YYWWNNN 8-lead PDIP 5-lead SOT23 8-ball VFBGA 1.5 x 2.0 mm Body ##%UYY WWNNN ATMLUYWW ###% CO YYWWNNN Note 1: ###U WNNN designates pin 1 Note 2: Package drawings are not to scale 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. Catalog Number Truncation AT24C01C Truncation Code ###: 01C / ##: 1C AT24C02C Truncation Code ###: 02C / ##: 2C Date Codes YY = Year 16: 2016 17: 2017 18: 2018 19: 2019 Voltages 20: 2020 21: 2021 22: 2022 23: 2023 Y = Year 6: 2016 7: 2017 8: 2018 9: 2019 0: 2020 1: 2021 2: 2022 3: 2023 WW = Work Week of Assembly 02: Week 2 04: Week 4 ... 52: Week 52 Country of Origin Device Grade CO = Country of Origin H or U: Industrial Grade % = Minimum Voltage M: 1.7V min Atmel Truncation AT: Atmel ATM: Atmel ATML: Atmel Trace Code NNN = Alphanumeric Trace Code (2 Characters for Small Packages) © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 24 AT24C01C/AT24C02C Packaging Information 8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging D A N B E1 NOTE 1 1 2 TOP VIEW E C A2 A PLANE L c A1 e eB 8X b1 8X b .010 C SIDE VIEW END VIEW Microchip Technology Drawing No. C04-018D Sheet 1 of 2 © 2017 Microchip Technology Incorporated © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 25 AT24C01C/AT24C02C Packaging Information 8-Lead Plastic Dual In-Line (P) - 300 mil Body [PDIP] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging ALTERNATE LEAD DESIGN (VENDOR DEPENDENT) DATUM A DATUM A b b e 2 e 2 e e Units Dimension Limits Number of Pins N e Pitch Top to Seating Plane A Molded Package Thickness A2 Base to Seating Plane A1 Shoulder to Shoulder Width E Molded Package Width E1 Overall Length D Tip to Seating Plane L c Lead Thickness Upper Lead Width b1 b Lower Lead Width Overall Row Spacing eB § MIN .115 .015 .290 .240 .348 .115 .008 .040 .014 - INCHES NOM 8 .100 BSC .130 .310 .250 .365 .130 .010 .060 .018 - MAX .210 .195 .325 .280 .400 .150 .015 .070 .022 .430 Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. § Significant Characteristic 3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .010" per side. 4. Dimensioning and tolerancing per ASME Y14.5M BSC: Basic Dimension. Theoretically exact value shown without tolerances. Microchip Technology Drawing No. C04-018D Sheet 2 of 2 © 2017 Microchip Technology Incorporated © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 26 AT24C01C/AT24C02C Packaging Information 8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 2X 0.10 C A–B D A D NOTE 5 N E 2 E1 2 E1 E NOTE 1 2 1 e B NX b 0.25 C A–B D NOTE 5 TOP VIEW 0.10 C C A A2 SEATING PLANE 8X A1 SIDE VIEW 0.10 C h R0.13 h R0.13 H 0.23 L SEE VIEW C (L1) VIEW A–A VIEW C Microchip Technology Drawing No. C04-057-SN Rev D Sheet 1 of 2 © 2017 Microchip Technology Incorporated © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 27 AT24C01C/AT24C02C Packaging Information 8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm (.150 In.) Body [SOIC] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging Units Dimension Limits Number of Pins N e Pitch Overall Height A Molded Package Thickness A2 § Standoff A1 Overall Width E Molded Package Width E1 Overall Length D Chamfer (Optional) h Foot Length L L1 Footprint Foot Angle c Lead Thickness b Lead Width Mold Draft Angle Top Mold Draft Angle Bottom MIN 1.25 0.10 0.25 0.40 0° 0.17 0.31 5° 5° MILLIMETERS NOM 8 1.27 BSC 6.00 BSC 3.90 BSC 4.90 BSC 1.04 REF - MAX 1.75 0.25 0.50 1.27 8° 0.25 0.51 15° 15° Notes: 1. Pin 1 visual index feature may vary, but must be located within the hatched area. 2. § Significant Characteristic 3. Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.15mm per side. 4. Dimensioning and tolerancing per ASME Y14.5M BSC: Basic Dimension. Theoretically exact value shown without tolerances. REF: Reference Dimension, usually without tolerance, for information purposes only. 5. Datums A & B to be determined at Datum H. Microchip Technology Drawing No. C04-057-SN Rev D Sheet 2 of 2 © 2017 Microchip Technology Incorporated © 2018 Microchip Technology Inc. Datasheet DS20006111A-page 28 AT24C01C/AT24C02C Packaging Information 8-Lead Plastic Small Outline (SN) - Narrow, 3.90 mm Body [SOIC] Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging SILK SCREEN C Y1 X1 E RECOMMENDED LAND PATTERN Units Dimension Limits E Contact Pitch Contact Pad Spacing C Contact Pad Width (X8) X1 Contact Pad Length (X8) Y1 MIN MILLIMETERS NOM 1.27 BSC 5.40 MAX 0.60 1.55 Notes: 1. Dimensioning and tolerancing per ASME Y14.5M BSC: Basic Dimension. Theoretically exact value shown without tolerances. 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