H CAT24C21 EE GEN FR ALO 1-kb Dual Mode Serial EEPROM for VESATM "Plug-and-Play" LE A D F R E ETM FEATURES Low power CMOS technology DDC1TM/DDC2TM interface compliant for monitor identification 1,000,000 program/erase cycles 400 kHz I2C bus compatible 100 year data retention 2.5 to 5.5 volt operation 8-lead DIP, SOIC, TSSOP, MSOP or TDFN 16-byte page write buffer packages Industrial temperature range Hardware write protect DESCRIPTION The CAT24C21 is a 1-kb Serial CMOS EEPROM internally organized as 128 words of 8 bits each. The device complies with the Video Electronics Standard Association's (VESATM), Display Data Channel (DDCTM) standards for "Plug-and-Play" monitors. The "transmitonly" mode (DDC1TM) is controlled by the VCLK clock input and the "bi-directional" mode (DDC2TM) is controlled by the SCL clock input, with both modes sharing a common SDA input/output (I/O). The transmit-only mode is a read-only mode, while the bi-directional mode is a read and write mode following the I2C protocol. In write mode the CAT24C21 features a 16-byte page write buffer. The device is available in 8-lead DIP, SOIC, TSSOP, MSOP and TDFN packages. PIN CONFIGURATION FUNCTIONAL SYMBOL DIP Package (L) SOIC Package (W) NC NC 1 2 3 8 7 6 VCC VCLK SCL NC NC NC VSS 4 5 SDA VSS NC 1 2 3 4 8 7 6 5 VCC VCC VCLK SCL SDA SCL CAT24C21 SDA TDFN Package (ZD4) MSOP Package (Z) VCLK NC NC NC VSS 1 2 3 4 8 7 6 5 VCC VCLK NC 1 8 VCC NC 2 7 VCLK SCL SDA NC 3 6 SCL VSS 4 5 SDA VSS 3 mm x 3 mm Top View PIN FUNCTIONS TSSOP Package (Y) NC NC NC VSS 1 2 3 4 8 7 6 5 Pin Name VCC VCLK SCL SDA (c) 2004 by Catalyst Semiconductor, Inc. Characteristics subject to change without notice 1 Function NC No Connect SDA Serial Data/Address SCL Serial Clock (bi-directional mode) VCLK Serial Clock (transmit-only mode) VCC Power Supply VSS Ground Doc. No.MD-1032, Rev. P CAT24C21 ABSOLUTE MAXIMUM RATINGS* *COMMENT Temperature Under Bias .................. -55C to +125C Stresses above those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions outside of those listed in the operational sections of this specification is not implied. Exposure to any absolute maximum rating for extended periods may affect device performance and reliability. Storage Temperature ........................ -65C to +150C Voltage on Any Pin with Respect to Ground(1) ............ -2.0 V to VCC + 2.0 V VCC with Respect to Ground .............. -2.0 V to +7.0 V Package Power Dissipation Capability (TA = 25C) .................................. 1.0 W Lead Soldering Temperature (10 seconds) ...... 300C Output Short Circuit Current(2) ....................... 100 mA RELIABILITY CHARACTERISTICS Symbol Parameter Reference Test Method Min Units NEND(3)(*) Endurance MIL-STD-883, Test Method 1033 1,000,000 Program/Erase Cycles Data Retention MIL-STD-883, Test Method 1008 100 Years VZAP(3) ESD Susceptibility MIL-STD-883, Test Method 3015 2000 Volts ILTH(3)(4) Latch-up JEDEC Standard 17 100 mA TDR (3) (*) Page Mode, VCC = 5 V, 25C D.C. OPERATING CHARACTERISTICS VCC = 2.5 V to 5.5 V, unless otherwise specified. Industrial temperature range. Symbol Max Units fSCL = 400 kHz 2 mA Standby Current VIN = GND or VCC 1 A ILI Input Leakage Current VIN = GND to VCC 10 A ILO Output Leakage Current VOUT = GND to VCC 10 A VIL Input Low Voltage -1 VCC x 0.3 V VIH Input High Voltage VCC x 0.7 VCC + 0.5 V VOL1 Output Low Voltage VCC = 3.0 V, IOL = 3 mA 0.4 V VCC 2.7 V 0.8 V ICC ISB (5) Parameter Test Conditions Power Supply Current VIL Input Low Voltage (VCLK) VIH Input High Voltage (VCLK) Min 2.0 V CAPACITANCE TA = 25C, f = 1.0 MHz, VCC = 5 V Symbol CI/O(3) CIN (3) Parameter Conditions Min Max Units Input/Output Capacitance (SDA) VI/O = 0 V 8 pF Input Capacitance (VCLK, SCL) VIN = 0 V 6 pF Note: (1) The minimum DC input voltage is -0.5 V. During transitions, inputs may undershoot to -2.0 V for periods of less than 20 ns. Maximum DC voltage on output pins is VCC + 0.5 V, which may overshoot to VCC + 2.0 V for periods of less than 20 ns. (2) Output shorted for no more than one second. (3) This parameter is tested initially and after a design or process change that affects the parameter. (4) Latch-up protection is provided for stresses up to 100 mA on I/O pins from -1 V to VCC + 1 V. (5) Maximum standby current (ISB) = 10A for the Extended Automotive temperature range. Doc. No. MD-1032, Rev. P 2 CAT24C21 A.C. CHARACTERISTICS VCC = 2.5 V to 5.5 V, unless otherwise specified. Industrial temperature range. Symbol Parameter Min Max Units 0.5 s Transmit-only Mode TVAA Output valid from VCLK TVHIGH VCLK high 0.6 s TVLOW VCLK low 1.3 s TVHZ Mode transition TVPU Transmit-only power-up 0.5 0 s ns Read & Write Cycle Limits FSCL Clock Frequency 400 kHz TI(1) Noise Suppression Time Constant at SCL, SDA Inputs 100 ns tAA SCL Low to SDA Data Out and ACK Out 1 s tBUF(1) Time the Bus Must be Free Before a New Transmission Can Start 1.2 s tHD:STA Start Condition Hold Time 0.6 s tLOW Clock Low Period 1.2 s tHIGH Clock High Period 0.6 s tSU:STA Start Condition Setup Time 0.6 s tHD:DAT Data In Hold Time 0 ns tSU:DAT Data In Setup Time 50 ns tR(1) SDA and SCL Rise Time 0.3 s tF(1) SDA and SCL Fall Time 300 ns tSU:STO t DH Stop Condition Setup Time 0.6 s Data Out Hold Time 100 ns Power-Up Timing(1)(2) tPUR Power-up to Read Operation 1 ms tPUW Power-up to Write Operation 1 ms 5 ms Write Cycle Limits tWR Write Cycle Time circuits are disabled, SDA is allowed to remain high, and the device does not respond to its slave address. The write cycle time is the time from a valid stop condition of a write sequence to the end of the internal program/ erase cycle. During the write cycle, the bus interface Note: (1) This parameter is tested initially and after a design or process change that affects the parameter. (2) tPUR and tPUW are the delays required from the time VCC is stable until the specified operation can be initiated. 3 Doc. No. MD-1032, Rev. P CAT24C21 PIN DESCRIPTION TRANSMIT-ONLY MODE: (DDC1) The SCL serial clock input pin is used to clock all data transfers into or out of the device when in the bi-directional mode. Upon power-up, the CAT24C21 will output valid data only after it has been initialized. During initialization, data will not be available until after the first nine clocks are sent to the device (Figure 2). The starting address for the transmit-only mode can be determined during initialization. If the SDA pin is high during the first eight clocks, the starting address will be 7FH. If the SDA pin is low during the first eight clocks, the starting address will be 00H. During the ninth clock, SDA will be in the high impedance state. The SDA bi-directional serial data/address pin is used to transfer data into and out of the device. The SDA pin is an open drain output and can be wire-ORed with other open drain or open collector outputs. FUNCTIONAL DESCRIPTION The CAT24C21 has two modes of operation: the transmitonly mode and the bi-directional mode. There is a separate 2-wire protocol to support each mode, each having a separate clock input (VCLK and SCL respectively) and both modes sharing a common bidirectional data line (SDA). The CAT24C21 enters the transmit-only mode upon power up and begins outputting data on the SDA pin with each clock signal on the VCLK pin. The device will remain in the transmit-only mode until there is a valid HIGH to LOW transition on the SCL pin, when it will switch to the bi-directional mode (Figure 1). Once in the bi-directinal mode, the only way to return to the transmit-only mode is by powering down the device. Data is transmitted in 8 bit words with the most significant bit first, followed by a 9th 'don't care' bit which will be in the high impedance state (Figure 3). The CAT24C21 will continuously sequence through the entire memory array as long as VCLK is present and no falling edges on SCL are detected. When the maximum address (7FH) is reached, addressing will wrap around to the zero location (00H) and transmitting will continue. The bi-directional mode clock (SCL) pin must be held high for the device to remain in the transmit-only mode. The VCLK serial clock input pin is used to clock data out of the device when in transmit-only mode. When held low, in bi-directional mode, it will inhibit write operations. Figure 1. Mode Transition Transmit-Only Mode Bi-Directional Mode SCL TVHZ SDA VCLK Figure 2. Device Initialization for Transmit-only Mode SCL SDA at high impedance for 9 clock cycles Bit8 SDA Bit7 Bit6 Bit5 Bit4 VCLK 1 2 3 4 5 6 7 TVPU Doc. No. MD-1032, Rev. P 8 9 10 11 TVAA 4 12 13 14 15 CAT24C21 BI-DIRECTIONAL MODE (DDC2) STOP Condition The following defines the features of the I2C bus protocol in bi-directional mode (Figure 4): A LOW to HIGH transition of SDA when SCL is HIGH determines the STOP condition. All operations must end with a STOP condition. (1) Data transfer may be initiated only when the bus is not busy. Device Addressing (2) During a data transfer, the data line must remain stable whenever the clock line is high. Any changes in the data line while the clock line is high will be interpreted as a START or STOP condition. The bus Master begins a transmission by sending a START condition. The Master then sends the address of the particular slave device it is requesting. The four most significant bits of the 8-bit slave address are fixed as 1010 for the CAT24C21 (see Fig. 8). The next three significant bits are "don't care". The last bit of the slave address specifies whether a Read or Write operation is to be performed. When this bit is set to 1, a Read operation is selected, and when set to 0, a Write operation is selected. When in the bi-directional mode, all inputs to the VCLK pin are ignored, except when a logic high is required to enable write capability. START Condition The START condition (Figure 6) precedes all commands to the device, and is defined as a HIGH to LOW transition of SDA when SCL is HIGH. The CAT24C21 monitors the SDA and SCL lines and will not respond until this condition is met. After the Master sends a START condition and the slave address byte, the CAT24C21 monitors the bus and responds with an acknowledge (on the SDA line) when its address matches the transmitted slave address. The CAT24C21 then performs a Read or Write operation depending on the state of the R/W bit. Figure 3. Transmit-only Mode SCL must remain high for transmit-only mode SCL SDA Bit8 (MSB) Bit7 Bit6 Bit5 Bit4 Bit3 Bit2 Bit1 (LSB) Don't Care Bit8 Bit7 VCLK TVHIGH TVLOW 5 Doc. No. MD-1032, Rev. P CAT24C21 Acknowledge Write Operations After a successful data transfer, each receiving device is required to generate an acknowledge (ACK). The acknowledging device pulls down the SDA line during the ninth clock cycle, signaling that it has received the 8 bits of data (Figure 7). VCLK must be held high in order to program the device. This applies to byte write and page write operation. Once the device is in its self-timed program cycle, VCLK can go low and not affect programming. The CAT24C21 responds with an ACK after receiving a START condition and its slave address. If the device has been selected along with a write operation, it responds with an ACK after receiving each 8-bit byte. In the Byte Write mode (Figure 9), the Master device sends the START condition and the slave address information (with the R/W bit set to zero) to the Slave device. After the Slave generates an ACK, the Master sends the byte address that is to be written into the address pointer of the CAT24C21. After receiving another ACK from the Slave, the Master device transmits the data byte to be written into the addressed memory location. The CAT24C21 acknowledges once more and the Master generates the STOP condition, at which time the device begins its internal programming cycle to nonvolatile memory (Figure 5). While this internal cycle is in progress, the device will not respond to any request from the Master device. Byte Write When the CAT24C21 is in a READ mode it transmits 8 bits of data, releases the SDA line, and monitors the line for an ACK. Once it receives this ACK, the CAT24C21 will continue to transmit data. If no ACK is sent by the Master, the device terminates data transmission and waits for a STOP condition. Figure 4. Bus Timing tF tHIGH tLOW tR tLOW SCL tSU:STA tHD:DAT tHD:STA tSU:DAT tSU:STO SDA IN tAA tBUF tDH SDA OUT Figure 5. Write Cycle Timing SCL SDA 8th Bit ACK Byte n tWR STOP CONDITION Doc. No. MD-1032, Rev. P 6 START CONDITION ADDRESS CAT24C21 Once all sixteen bytes are received and the STOP condition has been sent by the Master, the internal programming cycle begins. At this point all received data is written to the CAT24C21 in a single write cycle. Page Write The CAT24C21 writes up to 16 bytes of data in a single write cycle, using the Page Write operation. The Page Write operation (Figure 10) is initiated in the same manner as the Byte Write operation, however instead of terminating after the initial word is transmitted, the Master is allowed to send up to fifteen additional bytes. After each byte has been transmitted the CAT24C21 will respond with an ACK, and internally increment the low order address bits by one. The high order bits remain unchanged. Acknowledge Polling The disabling of the inputs can be used to take advantage of the typical write cycle time. Once the stop condition is issued to indicate the end of the host's write operation, the CAT24C21 initiates the internal write cycle. ACK polling can be initiated immediately. This involves issuing the start condition followed by the slave address for a write operation. If the CAT24C21 is still busy with the write operation, no ACK will be returned. If the CAT24C21 has completed the write operation, an ACK will be returned and the host can then proceed with the next read or write operation. If the Master transmits more than sixteen bytes prior to sending the STOP condition, the address counter `wraps around', and previously transmitted data will be overwritten. Figure 6. Start/Stop Timing SDA SCL START Bit STOP Bit Figure 7. Acknowledge Timing SCL FROM MASTER 1 8 9 DATA OUTPUT FROM TRANSMITTER DATA OUTPUT FROM RECEIVER START ACKNOWLEDGE Figure 8. Slave Address Bits 1 0 1 0 X 7 X X R/W Doc. No. MD-1032, Rev. P CAT24C21 Write Protection Selective Read When the VCLK pin is connected to GND and the CAT24C21 is in the bi-directional mode, the entire memory is protected and becomes "read only". Selective READ operations allow the Master device to select at random any memory location for a READ operation (Figure 12). The Master device first performs a `dummy' write operation by sending the START condition, slave address and byte address of the location it wishes to read. After the CAT24C21 acknowledges the word address, the Master device resends the START condition and the slave address, this time with the R/W bit set to one. The CAT24C21 then responds with its ACK and sends the 8-bit byte requested. The master device does not send an ACK but will generate a STOP condition. Read Operations The READ operation for the CAT24C21 is initiated in the same manner as the write operation with the one exception that the R/W bit is set to a one. Three different READ operations are possible: Immediate Address READ, Selective READ and Sequential READ. Immediate Address Read Sequential Read The CAT24C21's address counter contains the address of the last byte accessed, incremented by one. In other words, if the last READ or WRITE access was to address N, the READ immediately following would access data from address N + 1 (Figure 11). If N = 127, then the counter will 'wrap around' to address 0 and continue to clock out data. The Sequential READ operation (Figure 13) can be initiated by either the Immediate Address READ or the Selective READ operation. After the CAT24C21 sends the first 8-bit byte, the Master responds with an ACK, which tells the Slave that more data is being requested. The CAT24C21 will continue to output an 8-bit byte for each ACK sent by the Master. The entire memory content can thus be read out sequentially. If the end of memory is reached in the process, then addressing will 'wrap-around' to the beginning of memory. Data output will stop when the Master fails to acknowledge and sends a STOP condition. Figure 9. Byte Write Timing S T A R T BUS ACTIVITY: MASTER SDA LINE SLAVE ADDRESS S BYTE ADDRESS * * * S T O P DATA P * A C K A C K A C K Figure 10. Page Write Timing BUS ACTIVITY: MASTER SDA LINE S T A R T S SLAVE ADDRESS BYTE ADDRESS (n) DATA n DATA n+P P * * * * A C K A C K A C K nMAX = 7FH P = 15 for CAT24WC21 * = Don't care Doc. No. MD-1032, Rev. P DATA n+1 S T O P 8 A C K A C K CAT24C21 Figure 11. Immediate Address Read Timing BUS ACTIVITY: MASTER SDA LINE S T A R T S SLAVE ADDRESS S T O P *** P A C K DATA N O A C K SCL 8 9 8th Bit SDA DATA OUT NO ACK STOP Figure 12. Selective Read Timing BUS ACTIVITY: MASTER SDA LINE S T A R T SLAVE ADDRESS S S T A R T BYTE ADDRESS (n) *** S T O P SLAVE ADDRESS P S * A C K A C K A C K DATA n N O A C K Figure 13. Sequential Read Timing BUS ACTIVITY: MASTER SLAVE ADDRESS DATA n DATA n+1 DATA n+2 S T O P DATA n+x SDA LINE P A C K A C K A C K A C K N O A C K 9 Doc. No. MD-1032, Rev. P CAT24C21 EXAMPLE OF ORDERING INFORMATION Prefix Device # CAT Suffix 24C21 Company ID Y Product Number 24C21 L: W: Y: Z: ZD4: I - Temperature Range I = Industrial (-40C to +85C) E = Extended (-40C to +125C) (5) Package PDIP SOIC, JEDEC TSSOP MSOP (3) TDFN (3mm x 3mm) G T3 T: Tape & Reel 3: 3,000/Reel Lead Finish G: NiPdAu Blank: Matte-Tin For Product Top Mark Codes, click here: http://www.catsemi.com/techsupport/producttopmark.asp Notes: (1) All packages are RoHS-compliant (Lead-free, Halogen-free). (2) The device used in the above example is a CAT24C21YI-GT3 (TSSOP, Industrial Temperature, NiPdAu, Tape & Reel, 3,000/Reel). (3) For availability, please contact your nearest Catalyst Semiconductor Sales Office. (4) For additional package option please contact your nearest Catalyst Semiconductor Sales office. (5) Extended Temperature available upon request. Doc. No. MD-1032, Rev. P 10 CAT24C21 REVISION HISTORY Date Revsion 29-Sept-03 H 15-Oct-03 I 22-Oct-03 J 24-Oct-03 12-Nov-03 K L 23-Dec-03 07-Jul-04 27-Jul-04 24-Jun-08 M N O P Description Replaced Block Diagram with Functional Symbol Eliminated commercial temperature range Updated marking Added TDFN package Updated Pin Descriptions Updated DC Operating Characteristics Updated AC Characateristics Updated Byte Write Timing Figure Updated Page Write Timing Figure Updated Immediate Address Read Timing Figure Updated Reliability Characteristics Updated D.C. Operating Characteristics Updated Capacitance Formatting Change Corrected DC Operating Characteristics Corrected AC Characteristics Changed Industrial temp range from "Blank" to "I" in Ordering Information Added die revision to Ordering Information Updated DC Operating Characteristics table and notes Update Example of Ordering Information 11 Doc. No. MD-1032, Rev. P Copyrights, Trademarks and Patents (c) Catalyst Semiconductor, Inc. Trademarks and registered trademarks of Catalyst Semiconductor include each of the following: Adaptive AnalogTM, Beyond MemoryTM, DPPTM, EZDimTM, LDDTM, MiniPotTM, Quad-ModeTM and Quantum Charge ProgrammableTM I2C is a trademark of Philips Corporation. Catalyst Semiconductor is licensed by Philips Corporation to carry the I2C Bus Protocol. Catalyst Semiconductor has been issued U.S. and foreign patents and has patent applications pending that protect its products. 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Products with data sheets labeled "Advance Information" or "Preliminary" and other products described herein may not be in production or offered for sale. Catalyst Semiconductor advises customers to obtain the current version of the relevant product information before placing orders. Circuit diagrams illustrate typical semiconductor applications and may not be complete. Catalyst Semiconductor, Inc. Corporate Headquarters 2975 Stender Way Santa Clara, CA 95054 Phone: 408.542.1000 Fax: 408.542.1200 www.catsemi.com Publication #: Revison: Issue date: MD-1032 P 06/24/08