24AA256/24LC256/24FC256 256K I2CTM CMOS Serial EEPROM Device Selection Table Part Number VCC Range Max. Clock Frequency Temp. Ranges 24AA256 1.7-5.5V 400 kHz(1) I, E 24LC256 2.5-5.5V 400 kHz I, E 24FC256 1.7-5.5V 1 MHz(2) I * Temperature Ranges: - Industrial (I): - Automotive (E): Description: The Microchip Technology Inc. 24AA256/24LC256/ 24FC256 (24XX256*) is a 32K x 8 (256 Kbit) Serial Electrically Erasable PROM, capable of operation across a broad voltage range (1.7V to 5.5V). It has been developed for advanced, low-power applications such as personal communications or data acquisition. This device also has a page write capability of up to 64 bytes of data. This device is capable of both random and sequential reads up to the 256K boundary. Functional address lines allow up to eight devices on the same bus, for up to 2 Mbit address space. This device is available in the standard 8-pin plastic DIP, SOIC, TSSOP, MSOP, DFN and TDFN packages. The 24AA256 is also available in the 8-lead Chip Scale package. 100 kHz for VCC < 2.5V. 400 kHz for VCC < 2.5V. Note 1: 2: -40C to +85C -40C to +125C Features: * Single Supply with Operation Down to 1.7V for 24AA256 and 24FC256 Devices, 2.5V for 24LC256 Devices * Low-Power CMOS Technology: - Active current 400 uA, typical - Standby current 100 nA, typical * 2-Wire Serial Interface, I2CTM Compatible * Cascadable up to Eight Devices * Schmitt Trigger Inputs for Noise Suppression * Output Slope Control to Eliminate Ground Bounce * 100 kHz and 400 kHz Clock Compatibility * Page Write Time 5 ms Max. * Self-Timed Erase/Write Cycle * 64-Byte Page Write Buffer * Hardware Write-Protect * ESD Protection >4000V * More than One Million Erase/Write Cycles * Data Retention >200 years * Factory Programming Available * Packages Include 8-lead PDIP, SOIC, DFN, TDFN, TSSOP and MSOP * Pb-Free and RoHS Compliant Block Diagram A0 A1A2 WP I/O Control Logic Memory Control Logic HV Generator EEPROM Array XDEC Page Latches I/O SCL YDEC SDA VCC Sense Amp. R/W Control VSS Package Types TSSOP/MSOP(1) A1 2 A2 3 VSS 4 8 VCC 7 DFN/TDFN A0 1 8 VCC A0 1 WP A1 2 7 WP A1 2 6 SCL A2 3 6 SCL A2 3 5 SDA VSS 4 5 SDA VSS 4 CS (Chip Scale)(2) VCC A1 A0 8 VCC 24XX256 1 24XX256 A0 24XX256 PDIP/SOIC 7 WP 6 SCL 5 SDA 1 2 4 WP 6 3 5 7 A2 8 SDA SCL VSS (TOP DOWN VIEW, BALLS NOT VISIBLE) Note 1: * Pins A0 and A1 are no connects for the MSOP package only. Note 2: Available in I-temp, "AA" only. *24XX256 is used in this document as a generic part number for the 24AA256/24LC256/24FC256 devices. 1998-2013 Microchip Technology Inc. DS20001203T-page 1 24AA256/24LC256/24FC256 1.0 ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings() VCC .............................................................................................................................................................................6.5V All inputs and outputs w.r.t. VSS ......................................................................................................... -0.6V to VCC +1.0V Storage temperature ...............................................................................................................................-65C to +150C Ambient temperature with power applied ................................................................................................-40C to +125C ESD protection on all pins 4 kV NOTICE: Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to Absolute Maximum Rating conditions for extended periods may affect device reliability. TABLE 1-1: DC CHARACTERISTICS DC CHARACTERISTICS Param. No. Sym. Characteristic Electrical Characteristics: Industrial (I): VCC = +1.7V to 5.5V Automotive (E): VCC = +1.7V to 5.5V Min. Max. Units TA = -40C to +85C TA = -40C to +125C Conditions -- A0, A1, A2, SCL, SDA and WP pins: -- -- -- -- D1 VIH High-level input voltage 0.7 VCC -- V -- D2 VIL Low-level input voltage -- 0.3 VCC 0.2 VCC V V VCC 2.5V VCC < 2.5V D3 VHYS Hysteresis of Schmitt Trigger inputs (SDA, SCL pins) 0.05 VCC -- V VCC 2.5V (Note) D4 VOL Low-level output voltage -- 0.40 V IOL = 3.0 ma @ VCC = 4.5V IOL = 2.1 ma @ VCC = 2.5V D5 ILI Input leakage current -- 1 A VIN = VSS or VCC, WP = VSS VIN = VSS or VCC, WP = VCC D6 ILO Output leakage current -- 1 A VOUT = VSS or VCC D7 CIN, COUT Pin capacitance (all inputs/outputs) -- 10 pF VCC = 5.0V (Note) TA = 25C, FCLK = 1 MHz D8 ICC Read Operating current -- 400 A VCC = 5.5V, SCL = 400 kHz D9 ICCS ICC Write Note: Standby current -- 3 mA VCC = 5.5V -- 1 A TA = -40C to +85C SCL = SDA = VCC = 5.5V A0, A1, A2, WP = VSS -- 5 A TA = -40C to +125C SCL = SDA = VCC = 5.5V A0, A1, A2, WP = VSS This parameter is periodically sampled and not 100% tested. DS20001203T-page 2 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 TABLE 1-2: AC CHARACTERISTICS Electrical Characteristics: Industrial (I): VCC = +1.7V to 5.5V Automotive (E): VCC = +1.7V to 5.5V AC CHARACTERISTICS Param. No. Sym. Characteristic Min. Max. Units TA = -40C to +85C TA = -40C to +125C Conditions 1 FCLK Clock frequency -- -- -- -- 100 400 400 1000 kHz 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 2 THIGH Clock high time 4000 600 600 500 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 3 TLOW Clock low time 4700 1300 1300 500 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 4 TR SDA and SCL rise time (Note 1) -- -- -- 1000 300 300 ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 5.5V 24FC256 5 TF SDA and SCL fall time (Note 1) -- -- 300 100 ns All except, 24FC256 1.7V VCC 5.5V 24FC256 6 THD:STA Start condition hold time 4000 600 600 250 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 7 TSU:STA Start condition setup time 4700 600 600 250 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 8 THD:DAT Data input hold time 0 -- ns (Note 2) 9 TSU:DAT Data input setup time 250 100 100 -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 5.5V 24FC256 10 TSU:STO Stop condition setup time 4000 600 600 250 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 11 TSU:WP WP setup time 4000 600 600 -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 5.5V 24FC256 12 THD:WP WP hold time 4700 1300 1300 -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 5.5V 24FC256 Note 1: 2: 3: 4: Not 100% tested. CB = total capacitance of one bus line in pF. As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (minimum 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions. The combined TSP and VHYS specifications are due to new Schmitt Trigger inputs, which provide improved noise spike suppression. This eliminates the need for a TI specification for standard operation. This parameter is not tested but ensured by characterization. For endurance estimates in a specific application, please consult the Total EnduranceTM Model, which can be obtained from Microchip's web site at www.microchip.com. 1998-2013 Microchip Technology Inc. DS20001203T-page 3 24AA256/24LC256/24FC256 Electrical Characteristics: Industrial (I): VCC = +1.7V to 5.5V Automotive (E): VCC = +1.7V to 5.5V AC CHARACTERISTICS (Continued) Param. No. Sym. Characteristic TA = -40C to +85C TA = -40C to +125C Min. Max. Units Conditions -- -- -- -- 3500 900 900 400 ns 1.7 V VCC 2.5V 2.5 V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5 V VCC 5.5V 24FC256 4700 1300 1300 500 -- -- -- -- ns 1.7V VCC 2.5V 2.5V VCC 5.5V 1.7V VCC 2.5V 24FC256 2.5V VCC 5.5V 24FC256 10 + 0.1CB 250 250 ns All except, 24FC256 (Note 1) 13 TAA Output valid from clock (Note 2) 14 TBUF Bus free time: Time the bus must be free before a new transmission can start 15 TOF Output fall time from VIH minimum to VIL maximum CB 100 pF 16 TSP Input filter spike suppression (SDA and SCL pins) -- 50 ns All except, 24FC256 (Notes 1 and 3) 17 TWC Write cycle time (byte or page) -- 5 ms -- 18 -- Endurance 1,000,000 -- Note 1: 2: 3: 4: Not 100% tested. CB = total capacitance of one bus line in pF. As a transmitter, the device must provide an internal minimum delay time to bridge the undefined region (minimum 300 ns) of the falling edge of SCL to avoid unintended generation of Start or Stop conditions. The combined TSP and VHYS specifications are due to new Schmitt Trigger inputs, which provide improved noise spike suppression. This eliminates the need for a TI specification for standard operation. This parameter is not tested but ensured by characterization. For endurance estimates in a specific application, please consult the Total EnduranceTM Model, which can be obtained from Microchip's web site at www.microchip.com. FIGURE 1-1: BUS TIMING DATA 5 SCL cycles Page mode, 25C, 5.5V (Note 4) 7 SDA IN 3 4 D3 2 8 10 9 6 16 14 13 SDA OUT WP DS20001203T-page 4 (protected) (unprotected) 11 12 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: PIN FUNCTION TABLE 8-pin PDIP 8-pin SOIC 8-pin TSSOP 8-pin MSOP 8-pin DFN/TDFN CS A0 1 1 1 -- 1 3 User Configurable Chip Select A1 2 2 2 -- 2 2 User Configurable Chip Select (NC) -- -- -- 1, 2 -- -- Not Connected A2 3 3 3 3 3 5 User Configurable Chip Select VSS 4 4 4 4 4 8 Ground SDA 5 5 5 5 5 6 Serial Data Name Function SCL 6 6 6 6 6 7 Serial Clock (NC) -- -- -- -- -- -- Not Connected WP 7 7 7 7 7 4 Write-Protect Input VCC 8 8 8 8 8 1 +1.7V to 5.5V (24AA256) +2.5V to 5.5V (24LC256) +1.7V to 5.5V (24FC256) Note: 2.1 Exposed pad on DFN/TDFN can be connected to VSS or left floating. A0, A1, A2 Chip Address Inputs The A0, A1 and A2 inputs are used by the 24XX256 for multiple device operations. The levels on these inputs are compared with the corresponding bits in the slave address. The chip is selected if the compare is true. For the MSOP package only, pins A0 and A1 are not connected. Up to eight devices (two for the MSOP package) may be connected to the same bus by using different Chip Select bit combinations. These inputs must be connected to either VCC or VSS. In most applications, the chip address inputs A0, A1 and A2 are hard-wired to logic `0' or logic `1'. For applications in which these pins are controlled by a microcontroller or other programmable device, the chip address pins must be driven to logic `0' or logic `1' before normal device operation can proceed. 2.2 Serial Data (SDA) This is a bidirectional pin used to transfer addresses and data into and out of the device. It is an open drain terminal. Therefore, the SDA bus requires a pull-up resistor to VCC (typical 10 k for 100 kHz, 2 k for 400 kHz and 1 MHz). 2.3 Serial Clock (SCL) This input is used to synchronize the data transfer to and from the device. 2.4 Write-Protect (WP) This pin must be connected to either VSS or VCC. If tied to VSS, write operations are enabled. If tied to VCC, write operations are inhibited but read operations are not affected. 3.0 FUNCTIONAL DESCRIPTION The 24XX256 supports a bidirectional 2-wire bus and data transmission protocol. A device that sends data onto the bus is defined as a transmitter and a device receiving data as a receiver. The bus must be controlled by a master device which generates the Serial Clock (SCL), controls the bus access, and generates the Start and Stop conditions while the 24XX256 works as a slave. Both master and slave can operate as a transmitter or receiver, but the master device determines which mode is activated. For normal data transfer, SDA is allowed to change only during SCL low. Changes during SCL high are reserved for indicating the Start and Stop conditions. 1998-2013 Microchip Technology Inc. DS20001203T-page 5 24AA256/24LC256/24FC256 4.0 BUS CHARACTERISTICS The following bus protocol has been defined: * Data transfer may be initiated only when the bus is not busy. * During data transfer, the data line must remain stable whenever the clock line is high. Changes in the data line, while the clock line is high, will be interpreted as a Start or Stop condition. Accordingly, the following bus conditions have been defined (Figure 4-1). 4.1 Bus Not Busy (A) Both data and clock lines remain high. 4.2 Start Data Transfer (B) A high-to-low transition of the SDA line while the clock (SCL) is high, determines a Start condition. All commands must be preceded by a Start condition. 4.3 Stop Data Transfer (C) A low-to-high transition of the SDA line, while the clock (SCL) is high, determines a Stop condition. All operations must end with a Stop condition. DS20001203T-page 6 4.4 Data Valid (D) The state of the data line represents valid data when, after a Start condition, the data line is stable for the duration of the high period of the clock signal. The data on the line must be changed during the low period of the clock signal. There is one bit of data per clock pulse. Each data transfer is initiated with a Start condition and terminated with a Stop condition. The number of the data bytes transferred between the Start and Stop conditions is determined by the master device. 4.5 Acknowledge Each receiving device, when addressed, is obliged to generate an Acknowledge signal after the reception of each byte. The master device must generate an extra clock pulse which is associated with this Acknowledge bit. Note: The 24XX256 does not generate any Acknowledge bits if an internal programming cycle is in progress. A device that acknowledges must pull down the SDA line during the acknowledge clock pulse in such a way that the SDA line is stable low during the high period of the acknowledge related clock pulse. Of course, setup and hold times must be taken into account. During reads, a master must signal an end of data to the slave by NOT generating an Acknowledge bit on the last byte that has been clocked out of the slave. In this case, the slave (24XX256) will leave the data line high to enable the master to generate the Stop condition. 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 FIGURE 4-1: (A) DATA TRANSFER SEQUENCE ON THE SERIAL BUS (B) (D) Start Condition Address or Acknowledge Valid (D) (C) (A) SCL SDA FIGURE 4-2: Data Allowed to Change Stop Condition ACKNOWLEDGE TIMING Acknowledge Bit SCL SDA 1 2 3 4 5 6 7 Data from transmitter Transmitter must release the SDA line at this point, allowing the Receiver to pull the SDA line low to acknowledge the previous eight bits of data. 1998-2013 Microchip Technology Inc. 8 9 1 2 3 Data from transmitter Receiver must release the SDA line at this point so the Transmitter can continue sending data. DS20001203T-page 7 24AA256/24LC256/24FC256 5.0 DEVICE ADDRESSING FIGURE 5-1: A control byte is the first byte received following the Start condition from the master device (Figure 5-1). The control byte consists of a 4-bit control code. For the 24XX256, this is set as `1010' binary for read and write operations. The next three bits of the control byte are the Chip Select bits (A2, A1, A0). The Chip Select bits allow the use of up to eight 24XX256 devices on the same bus and are used to select which device is accessed. The Chip Select bits in the control byte must correspond to the logic levels on the corresponding A2, A1 and A0 pins for the device to respond. These bits are, in effect, the three Most Significant bits of the word address. For the MSOP package, the A0 and A1 pins are not connected. During device addressing, the A0 and A1 Chip Select bits (Figures 5-1 and 5-2) should be set to `0'. Only two 24XX256 MSOP packages can be connected to the same bus. The last bit of the control byte defines the operation to be performed. When set to a one, a read operation is selected. When set to a zero, a write operation is selected. The next two bytes received define the address of the first data byte (Figure 5-2). Because only A14...A0 are used, the upper address bits are a "don't care." The upper address bits are transferred first, followed by the Less Significant bits. Following the Start condition, the 24XX256 monitors the SDA bus checking the device type identifier being transmitted. Upon receiving a `1010' code and appropriate device select bits, the slave device outputs an Acknowledge signal on the SDA line. Depending on the state of the R/W bit, the 24XX256 will select a read or write operation. FIGURE 5-2: 0 1 Read/Write Bit Chip Select Bits Control Code S 1 0 1 A2 0 A1 A0 R/W ACK Slave Address Start Bit 5.1 Acknowledge Bit Contiguous Addressing Across Multiple Devices The Chip Select bits A2, A1 and A0 can be used to expand the contiguous address space for up to 2 Mbit by adding up to eight 24XX256 devices on the same bus. In this case, software can use A0 of the control byte as address bit A15; A1 as address bit A16; and A2 as address bit A17. It is not possible to sequentially read across device boundaries. For the MSOP package, up to two 24XX256 devices can be added for up to 512 Kbit of address space. In this case, software can use A2 of the control byte as address bit A17. Bits A0 (A15) and A1 (A16) of the control byte must always be set to a logic `0' for the MSOP. ADDRESS SEQUENCE BIT ASSIGNMENTS Control Byte 1 CONTROL BYTE FORMAT 0 Control Code DS20001203T-page 8 A 2 A 1 Chip Select Bits Address High Byte A 0 R/W x A A A A A 14 13 12 11 10 Address Low Byte A 9 A 8 A 7 * * * * * * A 0 x = "don't care" bit 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 6.0 WRITE OPERATIONS 6.1 Byte Write Following the Start condition from the master, the control code (four bits), the Chip Select (three bits) and the R/W bit (which is a logic low) are clocked onto the bus by the master transmitter. This indicates to the addressed slave receiver that the address high byte will follow after it has generated an Acknowledge bit during the ninth clock cycle. Therefore, the next byte transmitted by the master is the high-order byte of the word address and will be written into the Address Pointer of the 24XX256. The next byte is the Least Significant Address Byte. After receiving another Acknowledge signal from the 24XX256, the master device will transmit the data word to be written into the addressed memory location. The 24XX256 acknowledges again and the master generates a Stop condition. This initiates the internal write cycle and during this time, the 24XX256 will not generate Acknowledge signals (Figure 6-1). If an attempt is made to write to the array with the WP pin held high, the device will acknowledge the command but no write cycle will occur, no data will be written, and the device will immediately accept a new command. After a byte Write command, the internal address counter will point to the address location following the one that was just written. Note: 6.2 6.3 Write Protection The WP pin allows the user to write-protect the entire array (0000-7FFF) when the pin is tied to VCC. If tied to VSS the write protection is disabled. The WP pin is sampled at the Stop bit for every Write command (Figure 1-1). Toggling the WP pin after the Stop bit will have no effect on the execution of the write cycle. Note: Page write operations are limited to writing bytes within a single physical page, regardless of the number of bytes actually being written. Physical page boundaries start at addresses that are integer multiples of the page buffer size (or `page size') and end at addresses that are integer multiples of [page size - 1]. If a Page Write command attempts to write across a physical page boundary, the result is that the data wraps around to the beginning of the current page (overwriting data previously stored there), instead of being written to the next page, as might be expected. It is, therefore, necessary for the application software to prevent page write operations that would attempt to cross a page boundary. When doing a write of less than 64 bytes the data in the rest of the page is refreshed along with the data bytes being written. This will force the entire page to endure a write cycle, for this reason endurance is specified per page. Page Write The write control byte, word address and the first data byte are transmitted to the 24XX256 in much the same way as in a byte write. The exception is that instead of generating a Stop condition, the master transmits up to 63 additional bytes, which are temporarily stored in the on-chip page buffer, and will be written into memory once the master has transmitted a Stop condition. Upon receipt of each word, the six lower Address Pointer bits are internally incremented by one. If the master should transmit more than 64 bytes prior to generating the Stop condition, the address counter will roll over and the previously received data will be overwritten. As with the byte write operation, once the Stop condition is received, an internal write cycle will begin (Figure 6-2). If an attempt is made to write to the array with the WP pin held high, the device will acknowledge the command, but no write cycle will occur, no data will be written and the device will immediately accept a new command. 1998-2013 Microchip Technology Inc. DS20001203T-page 9 24AA256/24LC256/24FC256 FIGURE 6-1: BYTE WRITE SDA Line S T A R T Bus Activity AA S1 0 10A 2 10 0 Bus Activity Master Control Byte Bus Activity Master SDA Line Bus Activity Address Low Byte S T O P Data x P A C K x = "don't care" bit FIGURE 6-2: Address High Byte A C K A C K A C K PAGE WRITE S T A R T Control Byte Address High Byte AAA S101 02 1 00 x = "don't care" bit DS20001203T-page 10 Address Low Byte S T O P Data Byte 63 Data Byte 0 P x A C K A C K A C K A C K A C K 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 7.0 ACKNOWLEDGE POLLING Since the device will not acknowledge during a write cycle, this can be used to determine when the cycle is complete (This feature can be used to maximize bus throughput). Once the Stop condition for a Write command has been issued from the master, the device initiates the internally timed write cycle. ACK polling can be initiated immediately. This involves the master sending a Start condition, followed by the control byte for a Write command (R/W = 0). If the device is still busy with the write cycle, then no ACK will be returned. If no ACK is returned, the Start bit and control byte must be resent. If the cycle is complete, then the device will return the ACK and the master can then proceed with the next Read or Write command. See Figure 7-1 for flow diagram. FIGURE 7-1: ACKNOWLEDGE POLLING FLOW Send Write Command Send Stop Condition to Initiate Write Cycle Send Start Send Control Byte with R/W = 0 Did Device Acknowledge (ACK = 0)? NO YES Next Operation 1998-2013 Microchip Technology Inc. DS20001203T-page 11 24AA256/24LC256/24FC256 8.0 READ OPERATION 8.2 Random read operations allow the master to access any memory location in a random manner. To perform this type of read operation, the word address must first be set. This is done by sending the word address to the 24XX256 as part of a write operation (R/W bit set to `0'). Once the word address is sent, the master generates a Start condition following the acknowledge. This terminates the write operation, but not before the internal Address Pointer is set. The master then issues the control byte again, but with the R/W bit set to a one. The 24XX256 will then issue an acknowledge and transmit the 8-bit data word. The master will not acknowledge the transfer, though it does generate a Stop condition, which causes the 24XX256 to discontinue transmission (Figure 8-2). After a random Read command, the internal address counter will point to the address location following the one that was just read. Read operations are initiated in much the same way as write operations, with the exception that the R/W bit of the control byte is set to `1'. There are three basic types of read operations: current address read, random read and sequential read. 8.1 Current Address Read The 24XX256 contains an address counter that maintains the address of the last word accessed, internally incremented by `1'. Therefore, if the previous read access was to address `n' (n is any legal address), the next current address read operation would access data from address n + 1. Upon receipt of the control byte with R/W bit set to `1', the 24XX256 issues an acknowledge and transmits the 8-bit data word. The master will not acknowledge the transfer, but does generate a Stop condition and the 24XX256 discontinues transmission (Figure 8-1). FIGURE 8-1: S T A R T SDA Line S 1 0 1 0 A AA 1 2 1 0 Control Byte FIGURE 8-2: SDA Line Sequential Read Sequential reads are initiated in the same way as a random read except that after the 24XX256 transmits the first data byte, the master issues an acknowledge as opposed to the Stop condition used in a random read. This acknowledge directs the 24XX256 to transmit the next sequentially addressed 8-bit word (Figure 8-3). Following the final byte transmitted to the master, the master will NOT generate an acknowledge, but will generate a Stop condition. To provide sequential reads, the 24XX256 contains an internal Address Pointer which is incremented by one at the completion of each operation. This Address Pointer allows the entire memory contents to be serially read during one operation. The internal Address Pointer will automatically roll over from address 7FFF to address 0000 if the master acknowledges the byte received from the array address 7FFF. S T O P Data Byte P A C K Bus Activity Bus Activity Master 8.3 CURRENT ADDRESS READ Bus Activity Master Random Read N O A C K RANDOM READ S T A R T Control Byte Address High Byte S1 01 0 AAA0 2 1 0 Bus Activity x = "don't care" bit DS20001203T-page 12 S T A R T Address Low Byte x A C K A C K A C K Control Byte S 1 0 1 0 A A A1 2 1 0 S T O P Data Byte P A C K N O A C K 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 FIGURE 8-3: Bus Activity Master SEQUENTIAL READ Control Byte Data (n) Data (n + 1) S T O P Data (n + x) Data (n + 2) P SDA Line Bus Activity A C K 1998-2013 Microchip Technology Inc. A C K A C K A C K N O A C K DS20001203T-page 13 24AA256/24LC256/24FC256 9.0 PACKAGING INFORMATION 9.1 Package Marking Information 8-Lead PDIP (300 mil) 24AA256 I/P e3 017 0510 XXXXXXXX T/XXXNNN YYWW 8-Lead SOIC (150 mil) XXXXXXXT XXXXYYWW NNN Legend: XX...X T Y YY WW NNN e3 Example: 24LC256I SN e3 0510 017 8-Lead SOIC (208 mil) XXXXXXXX T/XXXXXX YYWWNNN Example: Example: 24LC256 I/SM e3 0510017 Part number or part number code Temperature (I, E) Year code (last digit of calendar year) Year code (last 2 digits of calendar year) Week code (week of January 1 is week `01') Alphanumeric traceability code (2 characters for small packages) Pb-free JEDEC designator for Matte Tin (Sn) Note: For very small packages with no room for the Pb-free JEDEC designator e3 , the marking will only appear on the outer carton or reel label. Note: In the event the full Microchip part number cannot be marked on one line, it will be carried over to the next line, thus limiting the number of available characters for customer-specific information. *Standard device marking consists of Microchip part number, year code, week code, and traceability code. For device marking beyond this, certain price adders apply. Please check with your Microchip Sales Office. DS20001203T-page 14 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Package Marking Information (Continued) Example: 8-Lead TSSOP XXXX TYWW NNN 4LD I510 017 8-Lead MSOP Example: XXXXXT YWWNNN 4L256I 510017 Example: 8-Lead DFN-S 24LC256 I/MF e3 0510 017 XXXXXXX T/XXXXX YYWW NNN Example: 8-Lead TDFN EF4 0510 017 XXX YWW NN Example: 8-Lead Chip Scale 249 A051 0017 XXX XYYW WNNN First Line Marking Codes Part No. TSSOP Package Codes MSOP Package Codes TDFN Package Codes 4AD 4A256T -- 24AA256 24LC256 4LD 4L256T EF4 24FC256 4FD 4F256T -- 1998-2013 Microchip Technology Inc. DS20001203T-page 15 24AA256/24LC256/24FC256 3 & ' !&" & 4# *!( !!& 4 %& &#& && 255***' '5 4 N NOTE 1 E1 1 3 2 D E A2 A L A1 c e eB b1 b 6&! '! 9'&! 7"') %! 7,8. 7 7 & ; < & & 7: 1, = = - 1!& & = = . - - ##4 "# & 4!! "# >#& ##4>#& . < : 9& -< -? 9 - < ) ? ) < 1 = = & & 9# 6 4!! 9#>#& 9 * 9#>#& : * + - !"#$%&" ' ()"&'"!&) &#*& & & # +%&, & !& - '! !#.# &"#' #%! & "! ! #%! & "! !! &$#/ !# '! #& .0 1,21!'! &$& "! **& "&& ! DS20001203T-page 16 * ,<1 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 1998-2013 Microchip Technology Inc. DS20001203T-page 17 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20001203T-page 18 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 ! ""#$%& !' 3 & ' !&" & 4# *!( !!& 4 %& &#& && 255***' '5 4 1998-2013 Microchip Technology Inc. DS20001203T-page 19 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20001203T-page 20 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 1998-2013 Microchip Technology Inc. DS20001203T-page 21 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20001203T-page 22 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 () )" * ! (+%+( ! 3 & ' !&" & 4# *!( !!& 4 %& &#& && 255***' '5 4 D N E E1 NOTE 1 1 2 b e c A A2 A1 L L1 6&! '! 9'&! 7"') %! 99. . 7 7 7: ; < & : 8 & = = < = ##4 4!! &# %% ?1, : >#& . ##4>#& . - ##49& - - 3 &9& 9 ? 3 & & 9 3 & 9# 4!! ?1, .3 R = #& ) = - !"#$%&" ' ()"&'"!&) &#*& & & # '! !#.# &"#' #%! & "! ! #%! & "! !! &$#'' !# - '! #& .0 1,2 1!'! &$& "! **& "&& ! .32 % '! ("!"*& "&& (% % '& " !! 1998-2013 Microchip Technology Inc. * ,#& . .$ !##9& - .$ !##>#& . - , &&>#& ) - < , &&9& 9 ? ?1, , &&& .$ !## U = !"#$%&" ' ()"&'"!&) &#*& & & # 4' ' $ !#&) !&#! - 4!!*!"&# '! #& .0 1,2 1!'! &$& "! **& "&& ! .32 % '! ("!"*& "&& (% % '& " !! = DS20001203T-page 28 * ,1 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 3 & ' !&" & 4# *!( !!& 4 %& &#& && 255***' '5 4 1998-2013 Microchip Technology Inc. DS20001203T-page 29 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20001203T-page 30 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 1998-2013 Microchip Technology Inc. DS20001203T-page 31 24AA256/24LC256/24FC256 , $ *-.200%31(, 3 & ' !&" & 4# *!( !!& 4 %& &#& && 255***' '5 4 DS20001203T-page 32 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 1998-2013 Microchip Technology Inc. DS20001203T-page 33 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging DS20001203T-page 34 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 Note: For the most current package drawings, please see the Microchip Packaging Specification located at http://www.microchip.com/packaging 1998-2013 Microchip Technology Inc. DS20001203T-page 35 24AA256/24LC256/24FC256 APPENDIX A: REVISION HISTORY Revision L Corrections to Section 1.0, Electrical Characteristics. Revision M Added 1.8V 400 kHz option for 24FC256. Revision N Revised Sections 2.1 and 2.4. Removed 14-Lead TSSOP Package. Revision P Revised Features; Changed 1.8V voltage to 1.7V; Replaced Package Drawings; Revised markings (8-lead SOIC); Revised Product ID System. Revision Q (05/10) Revised Table 1-1, Table 1-2, Section 6.1; Updated Package Drawings. Revision R (07/2011) Added Chip Scale package. Revision S (12/2012) Revise Automotive E temp. Revision T (04/2013) Added TDFN Package. DS20001203T-page 36 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 THE MICROCHIP WEB SITE CUSTOMER SUPPORT Microchip provides online support via our WWW site at 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: Users of Microchip products can receive assistance through several channels: * Product Support - Data sheets and errata, application notes and sample programs, design resources, user's 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 * * * * * Distributor or Representative Local Sales Office Field Application Engineer (FAE) Technical Support Development Systems Information Line 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://microchip.com/support 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 www.microchip.com. Under "Support", click on "Customer Change Notification" and follow the registration instructions. 1998-2013 Microchip Technology Inc. D20001203T-page 37 24AA256/24LC256/24FC256 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip product. If you wish to provide your comments on organization, clarity, subject matter, and ways in which our documentation can better serve you, please FAX your comments to the Technical Publications Manager at (480) 792-4150. Please list the following information, and use this outline to provide us with your comments about this document. TO: Technical Publications Manager RE: Reader Response Total Pages Sent ________ From: Name Company Address City / State / ZIP / Country Telephone: (_______) _________ - _________ FAX: (______) _________ - _________ Application (optional): Would you like a reply? Y N Device: 24AA256/24LC256/24FC256 Literature Number: D20001203T Questions: 1. What are the best features of this document? 2. How does this document meet your hardware and software development needs? 3. Do you find the organization of this document easy to follow? If not, why? 4. What additions to the document do you think would enhance the structure and subject? 5. What deletions from the document could be made without affecting the overall usefulness? 6. Is there any incorrect or misleading information (what and where)? 7. How would you improve this document? D20001203T-page 38 1998-2013 Microchip Technology Inc. 24AA256/24LC256/24FC256 PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. X Device Device: /XX Temperature Range 24AA256: 24AA256T: 24LC256: 24LC256T: 24FC256: 24FC256T: Temperature Range: I E Package: P SN SM ST MF = = Package 256 Kbit 1.7V I2C Serial EEPROM 256 Kbit 1.7V I2C Serial EEPROM Tape and Reel) 256 Kbit 2.5V I2C Serial EEPROM 256 Kbit 2.5V I2C Serial EEPROM Tape and Reel) 256 Kbit High Speed I2C Serial EEPROM 256 Kbit High Speed I2C Serial EEPROM Tape and Reel) -40C to +85C -40C to +125C = = = = = Plastic DIP (300 mil body), 8-lead Plastic SOIC (3.90 mm body), 8-lead Plastic SOIJ (5.28 mm body), 8-lead Plastic TSSOP (4.4 mm), 8-lead Dual, Flat, No Lead (DFN)(6x5 mm body), 8-lead MS = Plastic Micro Small Outline (MSOP), 8-lead MNY(2)=Dual, Flat, No Lead (TDFN) (2x3 mm body), 8-lead CS16K(1) = Chip Scale (CS), 8-lead (I-temp, "AA", Tape and Reel only) Examples: a) 24AA256-I/P: Industrial Temp., 1.7V, PDIP package. b) 24AA256T-I/SN: Tape and Reel, Industrial Temp., 1.7V, SOIC package. c) 24AA256-I/ST: Industrial Temp., 1.7V, TSSOP package. d) 24AA256-I/MS: Industrial Temp., 1.7V, MSOP package. e) 24LC256-E/P: Extended Temp., 2.5V, PDIP package. f) 24LC256-I/SN: Industrial Temp., 2.5V, SOIC package. g) 24LC256T-I/SN: Tape and Reel, Industrial Temp., 2.5V, SOIC package. h) 24LC256-I/MS: Industrial Temp, 2.5V, MSOP package. i) 24FC256-I/P: Industrial Temp, 1.7V, High Speed, PDIP package. j) 24FC256-I/SN: Industrial Temp, 1.7V, High Speed, SOIC package. k) 24FC256T-I/SN: Tape and Reel, Industrial Temp, 1.7V, High Speed, SOIC package. l) 24AA256T-CS16K: Industrial Temp, 1.7V, CS package, Tape and Reel. m) 24AA256T-E/SN: Tape and Reel, Extended Temp., 1.7V, SOIC package. Note 1: "16K" indicates 160K technology. 2: "Y" indicates a Nickel Palladium Gold (NiPdAu) finish. 1998-2013 Microchip Technology Inc. DS20001203T-page 39 24AA256/24LC256/24FC256 NOTES: DS20001203T-page 40 1998-2013 Microchip Technology Inc. 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. 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 buyer's 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. Trademarks The Microchip name and logo, the Microchip logo, dsPIC, FlashFlex, KEELOQ, KEELOQ logo, MPLAB, PIC, PICmicro, PICSTART, PIC32 logo, rfPIC, SST, SST Logo, SuperFlash and UNI/O are registered trademarks of Microchip Technology Incorporated in the U.S.A. and other countries. FilterLab, Hampshire, HI-TECH C, Linear Active Thermistor, MTP, SEEVAL and The Embedded Control Solutions Company are registered trademarks of Microchip Technology Incorporated in the U.S.A. Silicon Storage Technology is a registered trademark of Microchip Technology Inc. in other countries. Analog-for-the-Digital Age, Application Maestro, BodyCom, chipKIT, chipKIT logo, CodeGuard, dsPICDEM, dsPICDEM.net, dsPICworks, dsSPEAK, ECAN, ECONOMONITOR, FanSense, HI-TIDE, In-Circuit Serial Programming, ICSP, Mindi, MiWi, MPASM, MPF, MPLAB Certified logo, MPLIB, MPLINK, mTouch, Omniscient Code Generation, PICC, PICC-18, PICDEM, PICDEM.net, PICkit, PICtail, REAL ICE, rfLAB, Select Mode, SQI, Serial Quad I/O, Total Endurance, TSHARC, UniWinDriver, WiperLock, ZENA and Z-Scale 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. GestIC and ULPP are registered trademarks 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. (c) 1998-2013, Microchip Technology Incorporated, Printed in the U.S.A., All Rights Reserved. Printed on recycled paper. ISBN: 9781620771426 QUALITY MANAGEMENT SYSTEM CERTIFIED BY DNV == ISO/TS 16949 == 1998-2013 Microchip Technology Inc. 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(R) MCUs and dsPIC(R) DSCs, KEELOQ(R) 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. 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