24LC01B/02B 1K/2K 2.5V I2C Serial EEPROM FEATURES PACKAGE TYPES PDIP A0 1 8 Vcc A1 2 7 WP A2 3 6 SCL Vss 4 5 SDA A0 1 8 Vcc A1 2 7 WP A2 3 6 SCL Vss 4 5 SDA 24LC01B/02B SOIC 24LC01B/02B * Single supply with operation down to 2.5V * Low power CMOS technology - 1 mA active current typical - 10 A standby current typical at 5.5V - 5 A standby current typical at 3.0V * Organized as a single block of 128 bytes (128 x 8) or 256 bytes (256 x 8) * 2-wire serial interface bus, I2C compatible * 100kHz (2.5V) and 400kHz (5.0V) compatibility * Self-timed write cycle (including auto-erase) * Page-write buffer for up to 8 bytes * 2 ms typical write cycle time for page-write * Hardware write protect for entire memory * Can be operated as a serial ROM * ESD protection > 3,000V * 10,000,000 ERASE/WRITE cycles guaranteed on 24LC01B * 1,000,000 E/W cycles guaranteed on 24LC02B * Data retention > 200 years * 8 pin DIP or SOIC package * Available for extended temperature ranges - Commercial (C): 0C to +70C - Industrial (I): -40C to +85C BLOCK DIAGRAM DESCRIPTION The Microchip Technology Inc. 24LC01B and 24LC02B are 1K bit and 2K bit Electrically Erasable PROMs. The devices are organized as a single block of 128 x 8 bit or 256 x 8 bit memory with a two wire serial interface. Low voltage design permits operation down to 2.5 volts with a standby and active currents of only 5 A and 1 mA respectively. The 24LC01B and 24LC02B also have page-write capability for up to 8 bytes of data. The 24LC01B and 24LC02B are available in the standard 8-pin DIP and an 8-pin surface mount SOIC package. WP HV GENERATOR I/O CONTROL LOGIC MEMORY CONTROL LOGIC XDEC EEPROM ARRAY PAGE LATCHES SDA SCL YDEC VCC VSS SENSE AMP R/W CONTROL I2C is a trademark of Philips Corporation. 1996 Microchip Technology Inc. DS20071H-page 1 This document was created with FrameMaker 4 0 4 24LC01B/02B 1.0 ELECTRICAL CHARACTERISTICS 1.1 Maximum Ratings* TABLE 1-1: Name VCC...................................................................................7.0V All inputs and outputs w.r.t. VSS ............... -0.6V to VCC +1.0V Storage temperature ..................................... -65C to +150C Ambient temp. with power applied ................ -65C to +125C Soldering temperature of leads (10 seconds) ............. +300C ESD protection on all pins............................................. 4 kV Function VSS SDA SCL WP VCC A0, A1, A2 *Notice: Stresses above those listed under "Maximum ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at those or any other conditions above those indicated in the operational listings of this specification is not implied. Exposure to maximum rating conditions for extended periods may affect device reliability. TABLE 1-2: PIN FUNCTION TABLE Ground Serial Address/Data I/O Serial Clock Write Protect Input +2.5V to 5.5V Power Supply No Internal Connection DC CHARACTERISTICS VCC = +2.5V to +5.5V Parameter Symbol Min. WP, SCL and SDA pins: High level input voltage VIH .7 VCC Low level input voltage VIL Hysteresis of Schmidt trigger inputs VHYS Low level output voltage VOL Commercial (C): Tamb = 0C to +70C Industrial (I): Tamb = -40C to +85C Max. Units Conditions V .3 VCC V -- V (Note) .40 V IOL = 3.0 mA, VCC = 2.5V VIN = .1V to 5.5V .05 VCC Input leakage current ILI -10 10 A Output leakage current ILO -10 10 mA CIN, COUT -- 10 pF VCC = 5.0V (Note 1) Tamb = 25C, FCLK = 1 MHz ICC Write -- 3 mA VCC = 5.5V, SCL = 400 kHz ICC Read -- 1 mA ICCS -- 30 A VCC = 3.0V, SDA = SCL = VCC 100 A VCC = 5.5V, SDA = SCL = VCC Pin capacitance (all inputs/outputs) Operating current Standby current Note: VOUT = .1V to 5.5V This parameter is periodically sampled and not 100% tested. FIGURE 1-1: BUS TIMING START/STOP VHYS SCL THD:STA TSU:STA TSU:STO SDA START DS20071H-page 2 STOP 1996 Microchip Technology Inc. 24LC01B/02B TABLE 1-3: AC CHARACTERISTICS Parameter Symbol STANDARD MODE Vcc = 4.5 - 5.5V FAST MODE Min. Max. Min. Max. Units Remarks Clock frequency Clock high time Clock low time SDA and SCL rise time SDA and SCL fall time START condition hold time FCLK THIGH TLOW TR TF THD:STA -- 4000 4700 -- -- 4000 100 -- -- 1000 300 -- -- 600 1300 -- -- 600 400 -- -- 300 300 -- kHz ns ns ns ns ns START condition setup time TSU:STA 4700 -- 600 -- ns Data input hold time Data input setup time STOP condition setup time Output valid from clock Bus free time THD:DAT TSU:DAT TSU:STO TAA TBUF 0 250 4000 -- 4700 -- -- -- 3500 -- 0 100 600 -- 1300 -- -- -- 900 -- ns ns ns ns ns TOF -- 250 250 ns TSP -- 50 20 +0.1 CB -- (Note 2) Time the bus must be free before a new transmission can start (Note 1), CB 100 pF 50 ns (Note 3) TWR -- 10M 1M 10 -- -- 10M 1M 10 ms -- cycles Byte or Page mode 25C, Vcc = 5.0V, Block Mode (Note 4) Output fall time from VIH minimum to VIL maximum Input filter spike suppression (SDA and SCL pins) Write cycle time Endurance 24LC01B 24LC01B -- (Note 1) (Note 1) After this period the first clock pulse is generated Only relevant for repeated START condition (Note 2) Note 1: Not 100% tested. CB = total capacitance of one bus line in pF. 2: 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. 3: 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. 4: This parameter is not tested but guaranteed by characterization. For endurance estimates in a specific application, please consult the Total Endurance Model which can be obtained on our BBS or website. FIGURE 1-2: BUS TIMING DATA TR TF THIGH TLOW SCL TSU:STA SDA IN THD:DAT TSU:DAT TSU:STO THD:STA TSP TAA THD:STA TAA TBUF SDA OUT 1996 Microchip Technology Inc. DS20071H-page 3 24LC01B/02B 2.0 FUNCTIONAL DESCRIPTION The 24LC01B/02B supports a bi-directional two wire bus and data transmission protocol. A device that sends data onto the bus is defined as transmitter, and a device receiving data as receiver. The bus has to 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 24LC01B/02B works as slave. Both master and slave can operate as transmitter or receiver but the master device determines which mode is activated. 3.0 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 3-1). 3.1 3.4 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 clock pulse per bit of data. 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 and is theoretically unlimited, although only the last sixteen will be stored when doing a write operation. When an overwrite does occur it will replace data in a first in first out fashion. 3.5 Both data and clock lines remain HIGH. 3.2 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. 3.3 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 be ended with a STOP condition. FIGURE 3-1: (A) Acknowledge Each receiving device, when addressed, is obliged to generate an acknowledge after the reception of each byte. The master device must generate an extra clock pulse which is associated with this acknowledge bit. Note: Bus not Busy (A) Data Valid (D) The 24LC01B/02B does not generate any acknowledge bits if an internal programming cycle is in progress. The device that acknowledges has to 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. 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 must leave the data line HIGH to enable the master to generate the STOP condition. DATA TRANSFER SEQUENCE ON THE SERIAL BUS (B) (D) START CONDITION ADDRESS OR ACKNOWLEDGE VALID (D) (C) ( A) SCL SDA DS20071H-page 4 DATA ALLOWED TO CHANGE STOP CONDITION 1996 Microchip Technology Inc. 24LC01B/02B 3.6 Devide Address The 24LC01B/02B are software-compatible with older devices such as 24C01A, 24C02A, 24LC01, and 24LC02. A single 24LC02B can be used in place of two 24LC01's, for example, without any modifications to software. The "chip select" portion of the control byte becomes a don't care. The eighth bit of slave address determines if the master device wants to read or write to the 24LC01B/02B (Figure 3-2). The 24LC01B/02B monitors the bus for its corresponding slave address all the time. It generates an acknowledge bit if the slave address was true and it is not in a programming mode. Control Code Chip Select R/W Read Write 1010 1010 XXX XXX 1 0 FIGURE 3-2: R/W 1 0 1 0 X X A X X = Don't care FIGURE 4-1: BUS ACTIVITY MASTER SDA LINE BUS ACTIVITY MASTER SDA LINE Page Write BYTE WRITE S T A R T CONTROL BYTE WORD ADDRESS S T O P DATA S P A C K BUS ACTIVITY FIGURE 4-2: Byte Write The write control byte, word address and the first data byte are transmitted to the 24LC01B/02B in the same way as in a byte write. But instead of generating a stop condition the master transmits up to eight data bytes to the 24LC01B/02B which are temporarily stored in the on-chip page buffer and will be written into the memory after the master has transmitted a stop condition. After the receipt of each word, the three lower order address pointer bits are internally incremented by one. The higher order five bits of the word address remains constant. If the master should transmit more than eight words 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 4-2). READ/WRITE SLAVE ADDRESS 4.1 4.2 CONTROL BYTE ALLOCATION START WRITE OPERATION Following the start signal from the master, the device code (4 bits), the don't care bits (3 bits), and the R/W bit which is a logic low is placed onto the bus by the master transmitter. This indicates to the addressed slave receiver that a byte with a word address will follow after it has generated an acknowledge bit during the ninth clock cycle. Therefore the next byte transmitted by the master is the word address and will be written into the address pointer of the 24LC01B/02B. After receiving another acknowledge signal from the 24LC01B/02B the master device will transmit the data word to be written into the addressed memory location. The 24LC01B/ 02B acknowledges again and the master generates a stop condition. This initiates the internal write cycle, and during this time the 24LC01B/02B will not generate acknowledge signals (Figure 4-1). After generating a START condition, the bus master transmits the slave address consisting of a 4-bit device code (1010) for the 24LC01B/02B, followed by three don't care bits. Operation 4.0 A C K A C K PAGE WRITE S T A R T CONTROL BYTE WORD ADDRESS (n) DATA n S T O P DATAn + 7 DATAn + 1 S BUS ACTIVITY 1996 Microchip Technology Inc. P A C K A C K A C K A C K A C K DS20071H-page 5 24LC01B/02B 5.0 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 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 5-1 for flow diagram. FIGURE 5-1: ACKNOWLEDGE POLLING FLOW Send Write Command 7.0 Read operations are initiated in the same way as write operations with the exception that the R/W bit of the slave address is set to one. There are three basic types of read operations: current address read, random read, and sequential read. 7.1 Random Read Random read operations allow the master to access any memory location in a random manner. To perform this type of read operation, first the word address must be set. This is done by sending the word address to the 24LC01B/02B as part of a write operation. After 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. Then the master issues the control byte again but with the R/W bit set to a one. The 24LC01B/ 02B will then issue an acknowledge and transmits the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition and the 24LC01B/02B discontinues transmission (Figure 7-2). Send Stop Condition to Initiate Write Cycle Send Start Send Control Byte with R/W = 0 NO YES Next Operation 6.0 Current Address Read The 24LC01B/02B contains an address counter that maintains the address of the last word accessed, internally incremented by one. Therefore, if the previous access (either a read or write operation) was to address n, the next current address read operation would access data from address n + 1. Upon receipt of the slave address with R/W bit set to one, the 24LC01B/ 02B issues an acknowledge and transmits the eight bit data word. The master will not acknowledge the transfer but does generate a stop condition and the 24LC01B/ 02B discontinues transmission (Figure 7-1). 7.2 Did Device Acknowledge (ACK = 0)? READ OPERATION WRITE PROTECTION The 24LC01B/02B can be used as a serial ROM when the WP pin is connected to VCC. Programming will be inhibited and the entire memory will be write-protected. 7.3 Sequential Read Sequential reads are initiated in the same way as a random read except that after the 24LC01B/02B transmits the first data byte, the master issues an acknowledge as opposed to a stop condition in a random read. This directs the 24LC01B/02B to transmit the next sequentially addressed 8-bit word (Figure 7-3). To provide sequential reads the 24LC01B/02B 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. 7.4 Noise Protection The 24LC01B/02B employs a VCC threshold detector circuit which disables the internal erase/write logic if the VCC is below 1.5 volts at nominal conditions. The SCL and SDA inputs have Schmitt trigger and filter circuits which suppress noise spikes to assure proper device operation even on a noisy bus. DS20071H-page 6 1996 Microchip Technology Inc. 24LC01B/02B FIGURE 7-1: CURRENT ADDRESS READ BUS ACTIVITY MASTER S T A R T SDA LINE S CONTROL BYTE S T O P DATA n P A C K BUS ACTIVITY N O A C K FIGURE 7-2: RANDOM READ T S T A R T S S S T CONTROL BYTE BUS ACTIVITY A MASTER R SDA LINE WORD ADDRESS (n) S T O P DATA n P A C K A C K BUS ACTIVITY CONTROL BYTE N O A C K A C K FIGURE 7-3: SEQUENTIAL READ BUS ACTIVITY MASTER A C K CONTROL BYTE S T O P A C K A C K P SDA LINE BUS ACTIVITY A C K DATA n DATA n + 1 DATA n + 2 DATA n + X N O A C K 8.0 PIN DESCRIPTIONS 8.1 SDA Serial Address/Data Input/Output This is a bi-directional pin used to transfer addresses and data into and data out of the device. It is an open drain terminal, therefore the SDA bus requires a pull-up resistor to VCC (typical 10K for 100 kHz, 1K for 400 kHz). 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. 8.2 SCL Serial Clock This input is used to synchronize the data transfer from and to the device. 1996 Microchip Technology Inc. 8.3 WP This pin must be connected to either VSS or VCC. If tied to VSS, normal memory operation is enabled (read/write the entire memory). If tied to VCC, WRITE operations are inhibited. The entire memory will be write-protected. Read operations are not affected. This feature allows the user to use the 24LC01B/02B as a serial ROM when WP is enabled (tied to VCC). 8.4 A0, A1, A2 These pins are not used by the 24LC01B/02B. They may be left floating or tied to either VSS or VCC. DS20071H-page 7 24LC01B/02B NOTES: DS20071H-page 8 1996 Microchip Technology Inc. 24LC01B/02B NOTES: 1996 Microchip Technology Inc. DS20071H-page 9 24LC01B/02B NOTES: DS20071H-page 10 1996 Microchip Technology Inc. 24LC01B/02B 24LC01B/02B Product Identification System To order or to obtain information, e.g., on pricing or delivery, please use the listed part numbers, and refer to the factory or the listed sales offices. 24LC01B/02B - /P Package: Temperature Range: Device: 1996 Microchip Technology Inc. P = Plastic DIP (300 mil Body), 8-lead SN = Plastic SOIC (150 mil Body) SM = Plastic SOIC (207 mil Body) Blank = 0C to +70C I = -40C to +85C 24LC01B 24LC01BT 24LC02B 24LC02BT 1K I2C Serial EEPROM 1K I2C Serial EEPROM (Tape and Reel) 2K I2C Serial EEPROM 2K I2C Serial EEPROM (Tape and Reel) 1996 Microchip Technology Inc.DS20071H-page 11 WORLDWIDE SALES & SERVICE AMERICAS ASIA/PACIFIC EUROPE Corporate Office Microchip Technology Inc. 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 602 786-7200 Fax: 602 786-7277 Technical Support: 602 786-7627 Web: http://www.microchip.com Atlanta Microchip Technology Inc. 500 Sugar Mill Road, Suite 200B Atlanta, GA 30350 Tel: 770 640-0034 Fax: 770 640-0307 Boston Microchip Technology Inc. 5 Mount Royal Avenue Marlborough, MA 01752 Tel: 508 480-9990 Fax: 508 480-8575 Chicago Microchip Technology Inc. 333 Pierce Road, Suite 180 Itasca, IL 60143 Tel: 708 285-0071 Fax: 708 285-0075 Dallas Microchip Technology Inc. 14651 Dallas Parkway, Suite 816 Dallas, TX 75240-8809 Tel: 972 991-7177 Fax: 972 991-8588 Dayton Microchip Technology Inc. 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Unit 6, The Courtyard Meadow Bank, Furlong Road Bourne End, Buckinghamshire SL8 5AJ Tel: 44 1628 850303 Fax: 44 1628 850178 France Arizona Microchip Technology SARL Zone Industrielle de la Bonde 2 Rue du Buisson aux Fraises 91300 Massy - France Tel: 33 1 69 53 63 20 Fax: 33 1 69 30 90 79 Germany Arizona Microchip Technology GmbH Gustav-Heinemann-Ring 125 D-81739 Muenchen, Germany Tel: 49 89 627 144 0 Fax: 49 89 627 144 44 Italy Arizona Microchip Technology SRL Centro Direzionale Colleone Pas Taurus 1 Viale Colleoni 1 20041 Agrate Brianza Milan Italy Tel: 39 39 6899939 Fax: 39 39 689 9883 JAPAN Microchip Technology Intl. Inc. Benex S-1 6F 3-18-20, Shin Yokohama Kohoku-Ku, Yokohama Kanagawa 222 Japan Tel: 81 45 471 6166 Fax: 81 45 471 6122 9/3/96 All rights reserved. 1996, Microchip Technology Incorporated, USA. 9/96 Printed on recycled paper. Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates. No representation or warranty is given and no liability is assumed by Microchip Technology Incorporated with respect to the accuracy or use of such information, or infringement of patents or other intellectual property rights arising from such use or otherwise. Use of Microchip's products as critical components in life support systems is not authorized except with express written approval by Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights. The Microchip logo and name are registered trademarks of Microchip Technology Inc. All rights reserved. All other trademarks mentioned herein are the property of their respective companies. DS20071H-page 12 1996 Microchip Technology Inc.