FM24W256-GTR

FM24W256 256-Kbit (32 K × 8) Serial (I2C) F-RAM 256-Kbit (32 K × 8) Serial (I2C) F-RAM Features ■ ■ Functional Description 256-Kbit ferroelectric random access memory (F-RAM) logically organized as 32 K × 8 14 ❐ High-endurance 100 trillion (10 ) read/writes ❐ 151-year data retention (See the Data Retention and Endurance table) ❐ NoDelay™ writes ❐ Advanced high-reliability ferroelectric process The FM24W256 is a 256-Kbit nonvolatile memory employing an advanced ferroelectric process. A ferroelectric random access memory or F-RAM is nonvolatile and performs reads and writes similar to a RAM. It provides reliable data retention for 151 years while eliminating the complexities, overhead, and system-level reliability problems caused by EEPROM and other nonvolatile memories. Fast 2-wire Serial interface (I2C) ❐ Up to 1-MHz frequency 2 ❐ Direct hardware replacement for serial (I C) EEPROM ❐ Supports legacy timings for 100 kHz and 400 kHz Unlike EEPROM, the FM24W256 performs write operations at bus speed. No write delays are incurred. Data is written to the memory array immediately after each byte is successfully transferred to the device. The next bus cycle can commence without the need for data polling. In addition, the product offers substantial write endurance compared with other nonvolatile memories. Also, F-RAM exhibits much lower power during writes than EEPROM since write operations do not require an internally elevated power supply voltage for write circuits. The FM24W256 is capable of supporting 1014 read/write cycles, or 100 million times more write cycles than EEPROM. ■ Low power consumption ❐ 100 A active current at 100 kHz ❐ 15 A (typ) standby current ■ Wide voltage operation: VDD = 2.7 V to 5.5 V ■ Industrial temperature: –40 C to +85 C ■ 8-pin small outline integrated circuit (SOIC) package ■ Restriction of hazardous substances (RoHS) compliant These capabilities make the FM24W256 ideal for nonvolatile memory applications, requiring frequent or rapid writes. Examples range from data logging, where the number of write cycles may be critical, to demanding industrial controls where the long write time of EEPROM can cause data loss. The combination of features allows more frequent data writing with less overhead for the system. The FM24W256 provides substantial benefits to users of serial (I2C) EEPROM as a hardware drop-in replacement. The device specifications are guaranteed over an industrial temperature range of –40 C to +85 C. For a complete list of related documentation, click here. Logic Block Diagram Address Latch Counter 32 K x 8 F-RAM Array 15 8 SDA Serial to Parallel Converter Data Latch 8 SCL WP Control Logic A2-A0 Cypress Semiconductor Corporation Document Number: 001-84464 Rev. *K • 198 Champion Court • San Jose, CA 95134-1709 • 408-943-2600 Revised April 28, 2017 FM24W256 Contents Pinout ................................................................................ 3 Pin Definitions .................................................................. 3 Functional Overview ........................................................ 4 Memory Architecture ........................................................ 4 I2C Interface ...................................................................... 4 STOP Condition (P) ..................................................... 4 START Condition (S) ................................................... 4 Data/Address Transfer ................................................ 5 Acknowledge / No-acknowledge ................................. 5 Slave Device Address ................................................. 6 Addressing Overview .................................................. 6 Data Transfer .............................................................. 6 Memory Operation ............................................................ 6 Write Operation ........................................................... 6 Read Operation ........................................................... 7 Maximum Ratings ............................................................. 9 Operating Range ............................................................... 9 DC Electrical Characteristics .......................................... 9 Data Retention and Endurance ..................................... 10 Document Number: 001-84464 Rev. *K Capacitance .................................................................... 10 Thermal Resistance ........................................................ 10 AC Test Loads and Waveforms ..................................... 10 AC Test Conditions ........................................................ 10 AC Switching Characteristics ....................................... 11 Power Cycle Timing ....................................................... 12 Ordering Information ...................................................... 13 Ordering Code Definitions ......................................... 13 Package Diagrams .......................................................... 14 Acronyms ........................................................................ 16 Document Conventions ................................................. 16 Units of Measure ....................................................... 16 Document History Page ................................................. 17 Sales, Solutions, and Legal Information ...................... 18 Worldwide Sales and Design Support ....................... 18 Products .................................................................... 18 PSoC® Solutions ...................................................... 18 Cypress Developer Community ................................. 18 Technical Support ..................................................... 18 Page 2 of 18 FM24W256 Pinout Figure 1. 8-pin SOIC pinout A0 1 A1 2 A2 3 VSS 4 Top View not to scale 8 VDD 7 WP 6 SCL 5 SDA Pin Definitions Pin Name I/O Type Description A2-A0 Input Device Select Address 2-0. These pins are used to select one of up to 8 devices of the same type on the same I2C bus. To select the device, the address value on the three pins must match the corresponding bits contained in the slave address. The address pins are pulled down internally. SDA Input/Output Serial Data/Address. This is a bi-directional pin for the I2C interface. It is open-drain and is intended to be wire-AND'd with other devices on the I2C bus. The input buffer incorporates a Schmitt trigger for noise immunity and the output driver includes slope control for falling edges. An external pull-up resistor is required. SCL Input Serial Clock. The serial clock pin for the I2C interface. Data is clocked out of the device on the falling edge, and into the device on the rising edge. The SCL input also incorporates a Schmitt trigger input for noise immunity. WP Input Write Protect. When tied to VDD, addresses in the entire memory map will be write-protected. When WP is connected to ground, all addresses are write enabled. This pin is pulled down internally. VSS Power supply Ground for the device. Must be connected to the ground of the system. VDD Power supply Power supply input to the device. Document Number: 001-84464 Rev. *K Page 3 of 18 FM24W256 Functional Overview a new bus transaction can be shifted into the device, a write operation is complete. This is explained in more detail in the interface section. The FM24W256 is a serial F-RAM memory. The memory array is logically organized as 32,768 × 8 bits and is accessed using an industry-standard I2C interface. The functional operation of the F-RAM is similar to serial (I2C) EEPROM. The major difference between the FM24W256 and a serial (I2C) EEPROM with the same pinout is the F-RAM's superior write performance, high endurance, and low power consumption. I2C Interface The FM24W256 employs a bi-directional I2C bus protocol using few pins or board space. Figure 2 illustrates a typical system configuration using the FM24W256 in a microcontroller-based system. The industry standard I2C bus is familiar to many users but is described in this section. Memory Architecture By convention, any device that is sending data onto the bus is the transmitter while the target device for this data is the receiver. The device that is controlling the bus is the master. The master is responsible for generating the clock signal for all operations. Any device on the bus that is being controlled is a slave. The FM24W256 is always a slave device. When accessing the FM24W256, the user addresses 32K locations of eight data bits each. These eight data bits are shifted in or out serially. The addresses are accessed using the I2C protocol, which includes a slave address (to distinguish other non-memory devices) and a two-byte address. The upper bit of the address range is 'don't care' value. The complete address of 15 bits specifies each byte address uniquely. The bus protocol is controlled by transition states in the SDA and SCL signals. There are four conditions including START, STOP, data bit, or acknowledge. Figure 3 and Figure 4 illustrates the signal conditions that specify the four states. Detailed timing diagrams are shown in the electrical specifications section. The access time for the memory operation is essentially zero, beyond the time needed for the serial protocol. That is, the memory is read or written at the speed of the I2C bus. Unlike a serial (I2C) EEPROM, it is not necessary to poll the device for a ready condition because writes occur at bus speed. By the time Figure 2. System Configuration using Serial (I2C) nvSRAM RPmin = (VDD - VOLmax) / IOL V DD RPmax = tr / (0.8473 * Cb) SDA Microcontroller SCL V DD V DD A0 SCL A0 SCL A0 SCL A1 SDA A1 SDA A1 SDA WP A2 WP A2 #0 #1 A2 WP #7 STOP Condition (P) START Condition (S) A STOP condition is indicated when the bus master drives SDA from LOW to HIGH while the SCL signal is HIGH. All operations using the FM24W256 should end with a STOP condition. If an operation is in progress when a STOP is asserted, the operation will be aborted. The master must have control of SDA in order to assert a STOP condition. A START condition is indicated when the bus master drives SDA from HIGH to LOW while the SCL signal is HIGH. All commands should be preceded by a START condition. An operation in progress can be aborted by asserting a START condition at any time. Aborting an operation using the START condition will ready the FM24W256 for a new operation. If during operation the power supply drops below the specified VDD minimum, the system should issue a START condition prior to performing another operation. Document Number: 001-84464 Rev. *K Page 4 of 18 FM24W256 Figure 3. START and STOP Conditions full pagewidth SDA SDA SCL SCL S P STOP Condition START Condition Figure 4. Data Transfer on the I2C Bus handbook, full pagewidth P SDA Acknowledgement signal from slave MSB SCL S 1 2 7 9 8 1 Acknowledgement signal from receiver 2 3 4-8 ACK START condition 9 ACK All data transfers (including addresses) take place while the SCL signal is HIGH. Except under the three conditions described above, the SDA signal should not change while SCL is HIGH. Acknowledge / No-acknowledge The acknowledge takes place after the 8th data bit has been transferred in any transaction. During this state the transmitter should release the SDA bus to allow the receiver to drive it. The receiver drives the SDA signal LOW to acknowledge receipt of the byte. If the receiver does not drive SDA LOW, the condition is a no-acknowledge and the operation is aborted. S or P STOP or START condition Byte complete Data/Address Transfer S The receiver would fail to acknowledge for two distinct reasons. First is that a byte transfer fails. In this case, the no-acknowledge ceases the current operation so that the device can be addressed again. This allows the last byte to be recovered in the event of a communication error. Second and most common, the receiver does not acknowledge to deliberately end an operation. For example, during a read operation, the FM24W256 will continue to place data onto the bus as long as the receiver sends acknowledges (and clocks). When a read operation is complete and no more data is needed, the receiver must not acknowledge the last byte. If the receiver acknowledges the last byte, this will cause the FM24W256 to attempt to drive the bus on the next clock while the master is sending a new command such as STOP. Figure 5. Acknowledge on the I2C Bus handbook, full pagewidth DATA OUTPUT BY MASTER No Acknowledge DATA OUTPUT BY SLAVE Acknowledge SCL FROM MASTER 1 2 8 9 S START Condition Document Number: 001-84464 Rev. *K Clock pulse for acknowledgement Page 5 of 18 FM24W256 Slave Device Address sequential byte. If the acknowledge is not sent, the FM24W256 will end the read operation. For a write operation, the FM24W256 will accept 8 data bits from the master then send an acknowledge. All data transfer occurs MSB (most significant bit) first. The first byte that the FM24W256 expects after a START condition is the slave address. As shown in Figure 6, the slave address contains the device type or slave ID, the device select address bits, and a bit that specifies if the transaction is a read or a write. Memory Operation Bits 7-4 are the device type (slave ID) and should be set to 1010b for the FM24W256. These bits allow other function types to reside on the I2C bus within an identical address range. Bits 3-1 are the device select address bits. They must match the corresponding value on the external address pins to select the device. Up to eight FM24W256 devices can reside on the same I2C bus by assigning a different address to each. Bit 0 is the read/write bit (R/W). R/W = ‘1’ indicates a read operation and R/W = ‘0’ indicates a write operation. The FM24W256 is designed to operate in a manner very similar to other I2C interface memory products. The major differences result from the higher performance write capability of F-RAM technology. These improvements result in some differences between the FM24W256 and a similar configuration EEPROM during writes. The complete operation for both writes and reads is explained below. Write Operation Figure 6. Memory Slave Device Address MSB handbook, halfpage 1 All writes begin with a slave address, then a memory address. The bus master indicates a write operation by setting the LSB of the slave address (R/W bit) to a '0'. After addressing, the bus master sends each byte of data to the memory and the memory generates an acknowledge condition. Any number of sequential bytes may be written. If the end of the address range is reached internally, the address counter will wrap from 7FFFh to 0000h. LSB 0 1 Slave ID 0 A2 A1 A0 R/W Device Select Addressing Overview Unlike other nonvolatile memory technologies, there is no effective write delay with F-RAM. Since the read and write access times of the underlying memory are the same, the user experiences no delay through the bus. The entire memory cycle occurs in less time than a single bus clock. Therefore, any operation including read or write can occur immediately following a write. Acknowledge polling, a technique used with EEPROMs to determine if a write is complete is unnecessary and will always return a ready condition. After the FM24W256 (as receiver) acknowledges the slave address, the master can place the memory address on the bus for a write operation. The address requires two bytes. The complete 15-bit address is latched internally. Each access causes the latched address value to be incremented automatically. The current address is the value that is held in the latch; either a newly written value or the address following the last access. The current address will be held for as long as power remains or until a new value is written. Reads always use the current address. A random read address can be loaded by beginning a write operation as explained below. Internally, an actual memory write occurs after the 8th data bit is transferred. It will be complete before the acknowledge is sent. Therefore, if the user desires to abort a write without altering the memory contents, this should be done using START or STOP condition prior to the 8th data bit. The FM24W256 uses no page buffering. After transmission of each data byte, just prior to the acknowledge, the FM24W256 increments the internal address latch. This allows the next sequential byte to be accessed with no additional addressing. After the last address (7FFFh) is reached, the address latch will roll over to 0000h. There is no limit to the number of bytes that can be accessed with a single read or write operation. The memory array can be write-protected using the WP pin. Setting the WP pin to a HIGH condition (VDD) will write-protect all addresses. The FM24W256 will not acknowledge data bytes that are written to protected addresses. In addition, the address counter will not increment if writes are attempted to these addresses. Setting WP to a LOW state (VSS) will disable the write protect. WP is pulled down internally. Data Transfer After the address bytes have been transmitted, data transfer between the bus master and the FM24W256 can begin. For a read operation the FM24W256 will place 8 data bits on the bus then wait for an acknowledge from the master. If the acknowledge occurs, the FM24W256 will transfer the next Figure 7 and Figure 8 below illustrate a single-byte and multiple-byte write cycles. Figure 7. Single-Byte Write By Master Start S Stop Address & Data Slave Address By F-RAM Document Number: 001-84464 Rev. *K 0 A Address MSB A Address LSB A Data Byte A P Acknowledge Page 6 of 18 FM24W256 Figure 8. Multi-Byte Write Start Stop Address & Data By Master S Slave Address 0 A Address MSB By F-RAM A Address LSB A Data Byte A Data Byte A P Acknowledge Read Operation There are two basic types of read operations. They are current address read and selective address read. In a current address read, the FM24W256 uses the internal address latch to supply the address. In a selective read, the user performs a procedure to set the address to a specific value. Current Address & Sequential Read As mentioned above the FM24W256 uses an internal latch to supply the address for a read operation. A current address read uses the existing value in the address latch as a starting place for the read operation. The system reads from the address immediately following that of the last operation. To perform a current address read, the bus master supplies a slave address with the LSB set to a '1'. This indicates that a read operation is requested. After receiving the complete slave address, the FM24W256 will begin shifting out data from the current address on the next clock. The current address is the value held in the internal address latch. Beginning with the current address, the bus master can read any number of bytes. Thus, a sequential read is simply a current address read with multiple byte transfers. After each byte the internal address counter will be incremented. Note Each time the bus master acknowledges a byte, this indicates that the FM24W256 should read out the next sequential byte. There are four ways to properly terminate a read operation. Failing to properly terminate the read will most likely create a bus contention as the FM24W256 attempts to read out additional data onto the bus. The four valid methods are: 1. The bus master issues a no-acknowledge in the 9th clock cycle and a STOP in the 10th clock cycle. This is illustrated in the diagrams below. This is preferred. 2. The bus master issues a no-acknowledge in the 9th clock cycle and a START in the 10th. 3. The bus master issues a STOP in the 9th clock cycle. 4. The bus master issues a START in the 9th clock cycle. Figure 9. Current Address Read By Master Start No Acknowledge Address Stop S Slave Address By F-RAM 1 A Acknowledge Data Byte 1 P Data Figure 10. Sequential Read By Master Start Address No Acknowledge Acknowledge Stop S Slave Address By F-RAM Document Number: 001-84464 Rev. *K 1 A Acknowledge Data Byte A Data Byte 1 P Data Page 7 of 18 FM24W256 Selective (Random) Read There is a simple technique that allows a user to select a random address location as the starting point for a read operation. This involves using the first three bytes of a write operation to set the internal address followed by subsequent read operations. To perform a selective read, the bus master sends out the slave address with the LSB (R/W) set to 0. This specifies a write operation. According to the write protocol, the bus master then sends the address bytes that are loaded into the internal address latch. After the FM24W256 acknowledges the address, the bus master issues a START condition. This simultaneously aborts the write operation and allows the read command to be issued with the slave address LSB set to a '1'. The operation is now a current address read. Figure 11. Selective (Random) Read Start Address By Master Start No Acknowledge Address Stop S Slave Address 0 A By F-RAM Document Number: 001-84464 Rev. *K Address MSB A Address LSB Acknowledge A S Slave Address 1 A Data Byte 1 P Data Page 8 of 18 FM24W256 Maximum Ratings Exceeding maximum ratings may shorten the useful life of the device. These user guidelines are not tested. Storage temperature ................................ –55 C to +125 C Surface mount lead soldering temperature (10 seconds) ....................................... +260 C Electrostatic Discharge Voltage Human Body Model (AEC-Q100-002 Rev. E) .................. 3.5 kV Charged Device Model (AEC-Q100-011 Rev. B) ............. 1.25 kV Maximum accumulated storage time At 125 °C ambient temperature ................................. 1000 h At 85 °C ambient temperature ................................ 10 Years Latch-up current .................................................... > 140 mA Ambient temperature with power applied ................................... –55 °C to +125 °C * Exception: The “VIN < VDD + 1.0 V” restriction does not apply to the SCL and SDA inputs. Supply voltage on VDD relative to VSS .........–1.0 V to +7.0 V Operating Range Machine Model (AEC-Q100-003 Rev. E) ............................ 200 V Input voltage .......... –1.0 V to + 7.0 V and VIN < VDD + 1.0 V Range Ambient Temperature (TA) VDD DC voltage applied to outputs in High-Z state .................................... –0.5 V to VDD + 0.5 V Industrial –40 C to +85 C 2.7 V to 5.5 V Transient voltage (< 20 ns) on any pin to ground potential ................. –2.0 V to VDD + 2.0 V Package power dissipation capability (TA = 25 °C) ................................................. 1.0 W DC Electrical Characteristics Over the Operating Range Parameter Description VDD Power supply IDD Average VDD current Test Conditions SCL toggling between VDD – 0.3 V and VSS, other inputs VSS or VDD – 0.3 V. Min Typ [1] Max Unit 2.7 3.3 5.5 V fSCL = 100 kHz – – 100 A fSCL = 400 kHz – – 200 A fSCL = 1 MHz – – 400 A ISB Standby current SCL = SDA = VDD. All other inputs VSS or VDD. Stop command issued. – 15 30 A ILI Input leakage current (Except WP and A2-A0) VSS < VIN < VDD –1 – +1 A Input leakage current (for WP and A2-A0) VSS < VIN < VDD –1 – +100 A ILO Output leakage current VSS < VIN < VDD VIH Input HIGH voltage VIL Input LOW voltage VOL Output LOW voltage IOL = 3 mA Rin[2] Input resistance (WP, A2-A0) –1 – +1 A 0.7 × VDD – VDD + 0.3 V – 0.3 – 0.3 × VDD V – – 0.4 V For VIN = VIL (Max) 40 – – k For VIN = VIH (Min) 1 – – M Notes 1. Typical values are at 25 °C, VDD = VDD (typ). Not 100% tested. 2. The input pull-down circuit is strong (40 k) when the input voltage is below VIL and weak (1 M) when the input voltage is above VIH. Document Number: 001-84464 Rev. *K Page 9 of 18 FM24W256 Data Retention and Endurance Parameter TDR NVC Description Test condition TA = 85 C Data retention Endurance Min Max Unit 10 – Years TA = 75 C 38 – TA = 65 C 151 – Over operating temperature 1014 – Cycles Capacitance Parameter [3] Description Test Conditions CO Output pin capacitance (SDA) CI Input pin capacitance Max Unit 8 pF 6 pF TA = 25 C, f = 1 MHz, VDD = VDD(typ) Thermal Resistance Parameter [3] JA JC Description Thermal resistance (junction to ambient) Thermal resistance (junction to case) Test Conditions 8-pin SOIC Unit Test conditions follow standard test methods and procedures for measuring thermal impedance, per EIA / JESD51. 141 C/W 43 C/W AC Test Loads and Waveforms Figure 12. AC Test Loads and Waveforms 5.5 V 1.7 k OUTPUT 100 pF AC Test Conditions Input pulse levels .................................10% and 90% of VDD Input rise and fall times .................................................10 ns Input and output timing reference levels ................0.5 × VDD Output load capacitance ............................................ 100 pF Note 3. These parameters are guaranteed by design and are not tested. Document Number: 001-84464 Rev. *K Page 10 of 18 FM24W256 AC Switching Characteristics Over the Operating Range Alt. Parameter Parameter[4] Description fSCL[5] SCL clock frequency Min Max Min Max Min Max Unit – 0.1 – 0.4 – 1.0 MHz tSU; STA Start condition setup for repeated Start 4.7 – 0.6 – 0.25 – s tHD;STA Start condition hold time 4.0 – 0.6 – 0.25 – s tLOW Clock LOW period 4.7 – 1.3 – 0.6 – s tHIGH Clock HIGH period 4.0 – 0.6 – 0.4 – s tSU;DAT tSU;DATA Data in setup 250 – 100 – 100 – ns tHD;DAT tHD;DATA Data in hold 0 – 0 – 0 – ns Data output hold (from SCL @ VIL) 0 – 0 – 0 – ns – 1000 – 300 – 300 ns tDH [6] tr Input rise time tF[6] tf Input fall time tR – 300 – 300 – 100 ns 4.0 – 0.6 – 0.25 – s SCL LOW to SDA Data Out Valid – 3 – 0.9 – 0.55 s tBUF Bus free before new transmission 4.7 – 1.3 – 0.5 – s tSP Noise suppression time constant on SCL, SDA – 50 – 50 – 50 ns STOP condition setup tSU;STO tVD;DATA tAA Figure 13. Read Bus Timing Diagram tR ` tF tHIGH tSP tLOW tSP SCL tSU:SDA 1/fSCL tBUF tHD:DAT tSU:DAT SDA tDH tAA Stop Start Start Acknowledge Figure 14. Write Bus Timing Diagram tHD:DAT SCL tHD:STA tSU:STO tSU:DAT tAA SDA Start Stop Start Acknowledge Notes 4. Test conditions assume signal transition time of 10 ns or less, timing reference levels of VDD/2, input pulse levels of 0 to VDD(typ), and output loading of the specified IOL and load capacitance shown in Figure 12. 5. The speed-related specifications are guaranteed characteristic points along a continuous curve of operation from DC to fSCL (max). 6. These parameters are guaranteed by design and are not tested. Document Number: 001-84464 Rev. *K Page 11 of 18 FM24W256 Power Cycle Timing Over the Operating Range Parameter Description Min Max Unit tPU Power-up VDD(min) to first access (START condition) 1 – ms tPD Last access (STOP condition) to power-down (VDD(min)) 0 – µs tVR [7, 8] VDD power-up ramp rate 30 – µs/V tVF [7, 8] VDD power-down ramp rate 30 – µs/V VDD ~ ~ Figure 15. Power Cycle Timing VDD(min) tVR SDA I2 C START tVF tPD ~ ~ tPU VDD(min) I2 C STOP Notes 7. Slope measured at any point on the VDD waveform. 8. Guaranteed by design. Document Number: 001-84464 Rev. *K Page 12 of 18 FM24W256 Ordering Information Package Diagram Ordering Code FM24W256-G Package Type 51-85066 8-pin SOIC 001-85261 8-pin SOIC Operating Range Industrial FM24W256-GTR FM24W256-EG FM24W256-EGTR All these parts are Pb-free. Contact your local Cypress sales representative for availability of these parts. Ordering Code Definitions FM 24 W 256 - G TR Option: blank = Standard; TR = Tape and Reel Package Type: G = 8-pin SOIC; EG = EIAJ SOIC Density: 256 = 256-Kbit Voltage: W = 2.7 V to 5.5 V I2C F-RAM Cypress Document Number: 001-84464 Rev. *K Page 13 of 18 FM24W256 Package Diagrams Figure 16. 8-pin SOIC (150 Mils) Package Outline, 51-85066 51-85066 *H Document Number: 001-84464 Rev. *K Page 14 of 18 FM24W256 Package Diagrams (continued) Figure 17. 8-pin SOIC (208 Mils) Package Outline, 001-85261 001-85261 ** Document Number: 001-84464 Rev. *K Page 15 of 18 FM24W256 Acronyms Acronym Document Conventions Description Units of Measure ACK Acknowledge CMOS Complementary Metal Oxide Semiconductor °C degree Celsius EIA Electronic Industries Alliance I2C Hz hertz Inter-Integrated Circuit Kb 1024 bit I/O Input/Output kHz kilohertz JEDEC Joint Electron Devices Engineering Council k kilohm LSB Least Significant Bit MHz megahertz MSB Most Significant Bit M megaohm NACK No Acknowledge A microampere RoHS Restriction of Hazardous Substances s microsecond R/W Read/Write mA milliampere SCL Serial Clock Line ms millisecond SDA Serial Data Access ns nanosecond SOIC Small Outline Integrated Circuit  ohm WP Write Protect % percent pF picofarad V volt W watt Document Number: 001-84464 Rev. *K Symbol Unit of Measure Page 16 of 18 FM24W256 Document History Page Document Title: FM24W256, 256-Kbit (32 K × 8) Serial (I2C) F-RAM Document Number: 001-84464 Rev. ECN No. Submission Date Orig. of Change ** 3902082 02/25/2013 GVCH New spec *A 3924523 03/07/2013 GVCH Changed tPU timing parameter from 10 ms to 1 ms Changed RIN (high) spec from 4 Mto 1 M Description of Change *B 3985098 05/09/2013 GVCH Updated SOIC package marking scheme *C 4014247 05/29/2013 GVCH Added Appendix A - Errata for FM24W256 *D 4045469 06/30/2013 GVCH All errata items are fixed and the errata is removed. *E 4283420 02/19/2014 GVCH Converted to Cypress standard format Changed datasheet status from “Preliminary to Final” Updated Maximum Ratings table - Removed Moisture Sensitivity Level (MSL) - Added junction temperature and latch up current Added Input leakage current (ILI) for WP and A2-A0 Updated Data Retention and Endurance table Added Thermal Resistance table Removed Package Marking Scheme (top mark) *F 4272607 03/12/2014 GVCH Typo fixed (Power Cycle Timing): Invalid tREC spec removed *G 4562106 11/05/2014 GVCH Updated Functional Description: Added “For a complete list of related documentation, click here.” at the end. *H 4781114 05/29/2015 GVCH Updated Ordering Information: Fixed Typo (Replaced “001-85066” with “51-85066” in “Package Diagram” column). Updated Package Diagrams: spec 51-85066 – Changed revision from *F to *G. Updated to new template. *I 4874738 08/06/2015 *J 4951762 10/07/2015 *K 5718043 04/28/2017 Document Number: 001-84464 Rev. *K ZSK / PSR Updated Maximum Ratings: Removed “Maximum junction temperature”. Added “Maximum accumulated storage time”. Added “Ambient temperature with power applied”. LIZB / GVCH Updated Ordering Information: No change in part numbers. Removed “Not recommended for new designs” in “Package Type” column corresponding to “FM24W256-EG” and “FM24W256-EGTR”. Updated Package Diagrams: spec 51-85066 – Changed revision from *G to *H. AESATMP8 Updated logo and Copyright. Page 17 of 18 FM24W256 Sales, Solutions, and Legal Information Worldwide Sales and Design Support Cypress maintains a worldwide network of offices, solution centers, manufacturer’s representatives, and distributors. To find the office closest to you, visit us at Cypress Locations. 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Cypress products are not designed, intended, or authorized for use as critical components in systems designed or intended for the operation of weapons, weapons systems, nuclear installations, life-support devices or systems, other medical devices or systems (including resuscitation equipment and surgical implants), pollution control or hazardous substances management, or other uses where the failure of the device or system could cause personal injury, death, or property damage (“Unintended Uses”). A critical component is any component of a device or system whose failure to perform can be reasonably expected to cause the failure of the device or system, or to affect its safety or effectiveness. Cypress is not liable, in whole or in part, and you shall and hereby do release Cypress from any claim, damage, or other liability arising from or related to all Unintended Uses of Cypress products. You shall indemnify and hold Cypress harmless from and against all claims, costs, damages, and other liabilities, including claims for personal injury or death, arising from or related to any Unintended Uses of Cypress products. Cypress, the Cypress logo, Spansion, the Spansion logo, and combinations thereof, WICED, PSoC, CapSense, EZ-USB, F-RAM, and Traveo are trademarks or registered trademarks of Cypress in the United States and other countries. For a more complete list of Cypress trademarks, visit cypress.com. Other names and brands may be claimed as property of their respective owners. Document Number: 001-84464 Rev. *K Revised April 28, 2017 Page 18 of 18