DATASHEET X28HC256 FN8108 Rev 5.00 August 27, 2015 256k, 32k x 8-Bit, 5V, Byte Alterable EEPROM The X28HC256 is a second generation high performance CMOS 32k x 8 EEPROM. It is fabricated with Intersil's proprietary, textured poly floating gate technology, providing a highly reliable 5V only nonvolatile memory. The X28HC256 supports a 128-byte page write operation, effectively providing a 24s/byte write cycle, and enabling the entire memory to be typically rewritten in less than 0.8s. The X28HC256 also features DATA polling and Toggle bit polling, two methods of providing early end of write detection. The X28HC256 also supports the JEDEC standard software data protection feature for protecting against inadvertent writes during power-up and power-down. Endurance for the X28HC256 is specified as a minimum 100,000 write cycles per byte and an inherent data retention of 100 years. Features * Access time: 90ns * Simple byte and page write - Single 5V supply - No external high voltages or VP-P control circuits - Self timed - No erase before write - No complex programming algorithms - No overerase problem * Low power CMOS - Active: 60mA - Standby: 500A * Software data protection - Protects data against system level inadvertent writes * High speed page write capability * Highly reliable Direct WriteTM cell - Endurance: 100,000 cycles - Data retention: 100 years * Early end of write detection - DATA polling - Toggle bit polling * RoHS compliant 256k BIT EEPROM ARRAY X BUFFERS LATCHES AND DECODER A0 TO A14 ADDRESS INPUTS I/O BUFFERS AND LATCHES Y BUFFERS LATCHES AND DECODER I/O0 TO I/O7 CE OE WE CONTROL LOGIC AND TIMING DATA INPUTS/OUTPUTS VCC VSS FIGURE 1. BLOCK DIAGRAM FN8108 Rev 5.00 August 27, 2015 Page 1 of 19 X28HC256 Ordering Information PART NUMBER (Note 4) PART MARKING ACCESS TIME (ns) TEMP. RANGE (C) X28HC256JZ-15 (Notes 1, 3) X28HC256J-15 ZHY 150 0 to +70 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256JI-15 (Note 1) X28HC256JI-15 HY 150 -40 to +85 32 Ld PLCC N32.45x55 X28HC256JIZ-15 (Notes 1, 3) X28HC256JI-15 ZHY 150 -40 to +85 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256PZ-15 (Notes 2, 3) X28HC256P-15 HYZ 150 0 to +70 28 Ld PDIP (RoHS Compliant) E28.6 X28HC256PIZ-15 (Notes 2, 3) X28HC256PI-15 HYZ 150 -40 to +85 28 Ld PDIP (RoHS Compliant) E28.6 PACKAGE PKG. DWG. # X28HC256JZ-12 (Notes 1, 3) X28HC256J-12 ZHY 120 0 to +70 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256JI-12 (Note 1) X28HC256JI-12 HY 120 -40 to +85 32 Ld PLCC N32.45x55 X28HC256JIZ-12 (Notes 1, 3) X28HC256JI-12 ZHY 120 -40 to +85 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256PZ-12 (Notes 2, 3) X28HC256P-12 HYZ 120 0 to +70 28 Ld PDIP (RoHS Compliant) E28.6 X28HC256PIZ-12 (Notes 2, 3) X28HC256PI-12 HYZ 120 -40 to +85 28 Ld PDIP (RoHS Compliant) E28.6 X28HC256SZ-12 (Note 3) X28HC256S-12 HYZ 120 0 to +70 X28HC256SI-12 X28HC256SI-12 HY 120 -40 to +85 X28HC256SIZ-12 (Note 3) X28HC256SI-12 HYZ 120 -40 to +85 X28HC256JZ-90 (Notes 1, 3) X28HC256J-90 ZHY 90 0 to +70 28 Ld SOIC (300mils RoHS Compliant) MDP0027 28 Ld SOIC (300mils) M28.3 28 Ld SOIC (300mils RoHS Compliant) MDP0027 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256JI-90 (Note 1) X28HC256JI-90 HY 90 -40 to +85 32 Ld PLCC N32.45x55 X28HC256JIZ-90 (Notes 1, 3) X28HC256JI-90 ZHY 90 -40 to +85 32 Ld PLCC (RoHS Compliant) N32.45x55 X28HC256PZ-90 (Notes 2, 3) X28HC256P-90 HYZ 90 0 to +70 28 Ld PDIP (RoHS Compliant) E28.6 X28HC256PIZ-90 (Notes 2, 3) X28HC256PI-90 HYZ 90 -40 to +85 28 Ld PDIP (RoHS Compliant) E28.6 X28HC256SI-90 X28HC256SI-90 HY 90 -40 to +85 28 Ld SOIC (300mils) M28.3 X28HC256SIZ-90 (Note 3) X28HC256SI-90 HYZ 90 -40 to +85 28 Ld SOIC (300mils RoHS Compliant) MDP0027 NOTES: 1. Add "T*" suffix for tape and reel. Please refer to TB347 for details on reel specifications. 2. Pb-free PDIPs can be used for through hole wave solder processing only. They are not intended for use in Reflow solder processing applications. 3. These Intersil Pb-free plastic packaged products employ special Pb-free material sets, molding compounds/die attach materials, and 100% matte tin plate plus anneal (e3 termination finish, which is RoHS compliant and compatible with both SnPb and Pb-free soldering operations). Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. 4. For Moisture Sensitivity Level (MSL), please see product information page for X28HC256. For more information on MSL, please see tech brief TB363. FN8108 Rev 5.00 August 27, 2015 Page 2 of 19 X28HC256 Pin Configurations WE A13 NC VCC A7 A12 A14 X28HC256 (32 LD PLCC, LCC) TOP VIEW X28HC256 (28 LD FLATPACK, PDIP, SOIC) TOP VIEW A14 1 28 VCC A12 2 27 A7 3 26 WE A13 A6 4 25 A8 A6 5 29 A8 A5 5 24 A9 A5 A4 6 23 A11 28 27 A9 A11 OE A10 A4 A3 6 7 A2 8 9 26 25 A1 A0 10 11 24 23 9 20 A0 I/O0 10 19 CE I/O7 11 18 I/O6 I/O1 12 17 I/O5 I/O2 VSS 13 16 I/O4 14 15 I/O3 NC I/O0 12 22 13 21 14 15 16 17 18 19 20 NC OE A10 CE I/O7 I/O6 I/O5 A1 I/O4 21 NC I/O3 22 8 2 1 32 31 30 I/O2 VSS 7 I/O1 A3 A2 4 3 Pin Descriptions PIN NAME PIN # PDIP, SOIC PIN # PLCC, LCC A0, A1, A2, A3, A4, A5, A6, A7, A8, A9, A10, A11, A12, A13, A14 10, 9, 8, 7, 6, 5, 4, 3, 25, 24, 21, 23, 2, 26, 1 11, 10, 9, 8, 7, 6, 5, 4, 29, 28, 24, 27, 3, 30, 2 I/O0, I/O1, I/O2, I/O3, I/O4, I/O5, I/O6, I/O7 11, 12, 13, 15 16, 17, 18, 19 13, 14, 15, 18 19, 20, 21, 22 WE 27 31 Write Enable (WE) - The Write enable input controls the writing of data to the X28HC256. CE 20 23 Chip Enable (CE) - The Chip enable input must be LOW to enable all read/write operations. When CE is HIGH, power consumption is reduced. OE 22 25 Output Enable (OE) - The output enable input controls the data output buffers, and is used to initiate read operations. VCC 28 32 +5V VSS 14 16 Ground NC - 1, 12, 17, 26 FN8108 Rev 5.00 August 27, 2015 DESCRIPTION Addresses (A0 to A14) - Address inputs. The address inputs select an 8-bit memory location during a read or write operation. Data In/Data Out (I/O0 to I/O7) - Data input/output- Data is written to or read from the X28HC256 through the I/O pins. No Connect Page 3 of 19 X28HC256 Absolute Maximum Ratings Thermal Information Voltage on any Pin with Respect to VSS . . . . . . . . . . . . . . . . . . . . . 1V to +7V DC Output Current . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10mA Temperature Under Bias X28HC256. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -10C to +85C X28HC256I . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65C to +150C Storage Temperature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .-65C to +150C Pb-free Reflow Profile . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . see TB493 *Pb-free PDIPs can be used for through hole wave solder processing only. They are not intended for use in Reflow solder processing applications. Recommended Operating Conditions Temperature Range Commercial. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 0C to +70C Industrial . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . -40C to +85C Supply Voltage . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5V 10% CAUTION: Do not operate at or near the maximum ratings listed for extended periods of time. Exposure to such conditions may adversely impact product reliability and result in failures not covered by warranty. DC Electrical Specifications Across recommended operating conditions, unless otherwise specified. LIMITS PARAMETER SYMBOL MIN (Note 7) TEST CONDITIONS TYP (Note 5) MAX (Note 7) UNIT VCC Active Current (TTL Inputs) ICC CE = OE = VIL, WE = VIH, All I/O's = open, address inputs = 0.4V/2.4V levels at f = 10MHz 30 60 mA VCC Standby Current (TTL Inputs) ISB1 CE = VIH, OE = VIL, All I/O's = open, other inputs = VIH 1 2 mA VCC Standby Current (CMOS Inputs) ISB2 CE = VCC - 0.3V, OE = GND, All I/Os = open, other inputs = VCC - 0.3V 200 500 A 10 A Input Leakage Current Output Leakage Current ILI VIN = VSS to VCC ILO VOUT = VSS to VCC, CE = VIH Input Low Voltage VlL (Note 6) Input High Voltage VIH (Note 6) Output Low Voltage VOL IOL = 6mA Output High Voltage VOH IOH = -4mA 10 A -1 0.8 V 2 VCC + 1 V 0.4 V 2.4 V NOTES: 5. Typical values are for TA = +25C and nominal supply voltage. 6. VIL minimum and VIH maximum are for reference only and are not tested. 7. Compliance to datasheet limits is assured by one or more methods: production test, characterization and/or design. Power-up Timing SYMBOL MAX UNIT Power-up to Read PARAMETER tPUR, (Note 8) 100 s Power-up to Write tPUW, (Note 8) 5 ms NOTE: 8. This parameter is periodically sampled and not 100% tested. Capacitance TA = +25C, f = 1MHz, VCC = 5V. MAX UNIT CI/O (Note 8) SYMBOL Input/output capacitance TEST VI/O = 0V CONDITIONS 10 pF CIN (Note 8) Input capacitance VIN = 0V 6 pF Endurance and Data Retention PARAMETER Endurance Data retention FN8108 Rev 5.00 August 27, 2015 MIN MAX UNIT 100,000 Cycles 100 Years Page 4 of 19 X28HC256 Symbol Table AC Conditions of Test Input pulse levels 0V to 3V Input rise and fall times 5ns Input and output timing levels 1.5V WAVEFORM Mode Selection CE OE WE MODE I/O POWER L L H Read DOUT active L H L Write DIN active H X X Standby and write inhibit High Z standby X L X Write inhibit -- -- X X H Write inhibit -- -- INPUTS OUTPUTS Must be steady Will be steady May change from LOW to HIGH Will change from LOW to HIGH May change from HIGH to LOW Will change from HIGH to LOW Don't Care: Changes Allowed Changing: State Not Known N/A Center Line is High Impedance Equivalent AC Load Circuit 5V 1.92k OUTPUT 1.37k 30pF FIGURE 2. EQUIVALENT AC LOAD CIRCUIT AC Electrical Specifications Across recommended operating conditions, unless otherwise specified. X28HC256-70 X28HC256-90 X28HC256-12 X28HC256-15 SYMBOL MIN MIN MIN MIN Read Cycle Time tRC 70 Chip Enable Access Time tCE 70 90 120 150 ns Address Access Time tAA 70 90 120 150 ns Output Enable Access Time tOE 35 40 50 50 ns PARAMETER MAX MAX 90 MAX 120 MAX UNIT 150 ns CE LOW to Active Output tLZ (Note 9) 0 0 0 0 ns OE LOW to Active Output tOLZ (Note 9) 0 0 0 0 ns CE HIGH to High Z Output tHZ (Note 9) 35 40 50 50 ns OE HIGH to High Z Output tOHZ (Note 9) 35 40 50 50 ns Output Hold from Address Change tOH 0 0 0 0 ns NOTE: 9. tLZ minimum, tHZ, tOLZ minimum and tOHZ are periodically sampled and not 100% tested, tHZ and tOHZ are measured with CL = 5pF, from the point when CE, OE return HIGH (whichever occurs first) to the time when the outputs are no longer driven.. FN8108 Rev 5.00 August 27, 2015 Page 5 of 19 X28HC256 Read Cycle tRC ADDRESS tCE CE tOE OE VIH WE tOLZ tOHZ tLZ DATA I/O tOH HIGH Z tHZ DATA VALID DATA VALID tAA FIGURE 3. READ CYCLE Write Cycle Limits PARAMETER Write Cycle Time SYMBOL MIN tWC (Note 11) TYP (Note 10) MAX UNIT 3 5 ms Address Setup Time tAS 0 ns Address Hold Time tAH 50 ns Write Setup Time tCS 0 ns Write Hold Time tCH 0 ns CE Pulse Width tCW 50 ns OE HIGH Setup Time tOES 0 ns OE HIGH Hold Time tOEH 0 ns WE Pulse Width tWP 50 ns tWPH (Note 12) 50 ns WE HIGH Recovery (page write only) Data Valid tDV Data Setup tDS 50 ns Data Hold tDH 0 ns tDW (Note 12) 10 s tBLC 0.15 Delay to Next Write After Polling is True Byte Load Cycle 1 100 s s NOTES: 10. Typical values are for TA = +25C and nominal supply voltage. 11. tWC is the minimum cycle time to be allowed from the system perspective unless polling techniques are used. It is the maximum time the device requires to automatically complete the internal write operation. 12. tWPH and tDW are periodically sampled and not 100% tested. FN8108 Rev 5.00 August 27, 2015 Page 6 of 19 X28HC256 WE Controlled Write Cycle tWC ADDRESS tAS tAH tCS tCH CE OE tOES tOEH tWP WE DATA IN DATA VALID tDS tDH HIGH Z DATA OUT FIGURE 4. WE CONTROLLED WRITE CYCLE CE Controlled Write Cycle tWC ADDRESS tAS tAH tCW CE tOES OE tOEH tCS tCH WE DATA VALID DATA IN tDS DATA OUT tDH HIGH Z FIGURE 5. CE CONTROLLED WRITE CYCLE S FN8108 Rev 5.00 August 27, 2015 Page 7 of 19 X28HC256 Page Write Cycle OE (Note 13) CE tBLC tWP WE tWPH ADDRESS (Note 14, 15) LAST BYTE I/O BYTE 0 BYTE 1 BYTE 2 BYTE n BYTE n + 1 BYTE n + 2 tWC FIGURE 6. PAGE WRITE CYCLE NOTES: 13. Between successive byte writes within a page write operation, OE can be strobed LOW: e.g. this can be done with CE and WE HIGH to fetch data from another memory device within the system for the next write; or with WE HIGH and CE LOW effectively performing a polling operation. 14. The timings shown above are unique to page write operations. Individual byte load operations within the page write must conform to either the CE or WE controlled write cycle timing. 15. For each successive write within the page write operation, A7 to A15 should be the same or writes to an unknown address could occur. FN8108 Rev 5.00 August 27, 2015 Page 8 of 19 X28HC256 DATA Polling Timing Diagram (Note 16) ADDRESS An An An CE WE tOEH tOES OE tDW I/O7 DIN = X DOUT = X DOUT = X tWC FIGURE 6. DATA POLLING TIMING DIAGRAM Toggle Bit Timing Diagram (Note 16) CE WE tOES tOEH OE tDW I/O6 HIGH Z (Note 17) tWC (Note 17) FIGURE 7. TOGGLE BIT TIMING DIAGRAM NOTES: 16. Polling operations are by definition read cycles and are therefore subject to read cycle timings. 17. I/O6 beginning and ending state will vary, depending upon actual tWC. FN8108 Rev 5.00 August 27, 2015 Page 9 of 19 X28HC256 Device Operation DATA Polling (I/O7) Read Read operations are initiated by both OE and CE LOW. The read operation is terminated by either CE or OE returning HIGH. This two line control architecture eliminates bus contention in a system environment. The data bus will be in a high impedance state when either OE or CE is HIGH. Write Write operations are initiated when both CE and WE are LOW and OE is HIGH. The X28HC256 supports both a CE and WE controlled write cycle. That is, the address is latched by the falling edge of either CE or WE, whichever occurs last. Similarly, the data is latched internally by the rising edge of either CE or WE, whichever occurs first. A byte write operation, once initiated, will automatically continue to completion, typically within 3ms. The X28HC256 features DATA polling as a method to indicate to the host system that the byte write or page write cycle has completed. DATA polling allows a simple bit test operation to determine the status of the X28HC256. This eliminates additional interrupt inputs or external hardware. During the internal programming cycle, any attempt to read the last byte written will produce the complement of that data on I/O7 (i.e., write data = 0xxx xxxx, read data = 1xxx xxxx). Once the programming cycle is complete, I/O7 will reflect true data. Toggle Bit (I/O6) The X28HC256 also provides another method for determining when the internal write cycle is complete. During the internal programming cycle I/O6 will toggle from high-to-low and high-tolow on subsequent attempts to read the device. When the internal cycle is complete the toggling will cease and the device will be accessible for additional read and write operations. Page Write Operation DATA Polling I/O The page write feature of the X28HC256 allows the entire memory to be written in typically 0.8 seconds. The page write allows up to 128 bytes of data to be consecutively written to the X28HC256, prior to the commencement of the internal programming cycle. The host can fetch data from another device within the system during a page write operation (change the source address), but the page address (A7 through A14) for each subsequent valid write cycle to the part during this operation must be the same as the initial page address. DATA polling can effectively halve the time for writing to the X28HC256. The timing diagram in Figure 8 on page 11 illustrates the sequence of events on the bus. The software flow diagram in Figure 9 on page 11 illustrates one method of implementing the routine. The page write mode can be initiated during any write operation. Following the initial byte write cycle, the host can write an additional one to 127 bytes in the same manner as the first byte was written. Each successive byte load cycle, started by the WE high-to-low transition, must begin within 100s of the falling edge of the preceding WE. If a subsequent WE high-to-low transition is not detected within 100s, the internal automatic programming cycle will commence. There is no page write window limitation. Effectively the page write window is infinitely wide, so long as the host continues to access the device within the byte load cycle time of 100s. Write Operation Status Bits The X28HC256 provides the user two write operation status bits. These can be used to optimize a system write cycle time. The status bits are mapped onto the I/O bus as shown in Figure 7. I/O DP TB 5 4 3 2 1 The Toggle Bit I/O The toggle bit can eliminate the chore of saving and fetching the last address and data in order to implement DATA polling. This can be especially helpful in an array comprised of multiple X28HC256 memories that is frequently updated. The timing diagram in Figure 10 on page 12 illustrates the sequence of events on the bus. The software flow diagram in Figure 11 on page 12 illustrates a method for polling the toggle bit. Hardware Data Protection The X28HC256 provides two hardware features that protects nonvolatile data from inadvertent writes. * Default VCC Sense -- All write functions are inhibited when VCC is 3.5V typically. * Write Inhibit -- Holding either OE low, WE high, or CE high will prevent an inadvertent write cycle during power-up and power-down, maintaining data integrity. 0 RESERVED TOGGLE BIT DATA POLLING FIGURE 7. STATUS BIT ASSIGNMENT FN8108 Rev 5.00 August 27, 2015 Page 10 of 19 X28HC256 WE LAST WRITE CE OE VIH VOH HIGH Z I/O7 VOL A0 TO A14 An An An X28HC256 READY An An An An FIGURE 8. DATA POLLING BUS SEQUENCE WRITE DATA NO WRITES COMPLETE? YES SAVE LAST DATA AND ADDRESS READ LAST ADDRESS IO7 COMPARE? NO YES X28HC256 READY FIGURE 9. DATA POLLING SOFTWARE FLOW FN8108 Rev 5.00 August 27, 2015 Page 11 of 19 X28HC256 LAST WRITE WE CE OE VOH I/O6 HIGH Z VOL (Note 18) (Note 18) X28C512, X28C513 READY NOTE: 18. I/O6 Beginning and ending state of I/O6 will vary. FIGURE 10. TOGGLE BIT BUS SEQUENCE Software Data Protection The X28HC256 offers a software controlled data protection feature. The X28HC256 is shipped from Intersil with the software data protection NOT ENABLED; that is, the device will be in the standard operating mode. In this mode data should be protected during power-up/down operations through the use of external circuits. The host would then have open read and write access of the device once VCC was stable. LAST WRITE YES LOAD ACCUM FROM ADDR n The X28HC256 can be automatically protected during power-up and power-down (without the need for external circuits) by employing the software data protection feature. The internal software data protection circuit is enabled after the first write operation, utilizing the software algorithm. This circuit is nonvolatile, and will remain set for the life of the device unless the reset command is issued. COMPARE ACCUM WITH ADDR n COMPARE OK? NO YES X28C256 READY FIGURE 11. TOGGLE BIT SOFTWARE FLOW FN8108 Rev 5.00 August 27, 2015 Once the software protection is enabled, the X28HC256 is also protected from inadvertent and accidental writes in the powered up state. That is, the software algorithm must be issued prior to writing additional data to the device. Software Algorithm Selecting the software data protection mode requires the host system to precede data write operations by a series of three write operations to three specific addresses. Refer to Figures 12 and 13 on page 13 for the sequence. The 3 byte sequence opens the page write window, enabling the host to write from one to 128 bytes of data. Once the page load cycle has been completed, the device will automatically be returned to the data protected state. Page 12 of 19 X28HC256 Software Data Protection VCC (VCC) 0V DATA ADDRESS AA 5555 55 2AAA A0 5555 WRITES OK tWC WRITE PROTECTED CE tBLC MAX WE BYTE OR AGE FIGURE 12. TIMING SEQUENCE BYTE OR PAGE WRITE Regardless of whether the device has previously been protected or not, once the software data protection algorithm is used and data has been written, the X28HC256 will automatically disable further writes unless another command is issued to cancel it. If no further commands are issued the X28HC256 will be write protected during power-down and after any subsequent power-up. WRITE DATA AA TO ADDRESS 5555 WRITE DATA 55 TO ADDRESS 2AAA Note: Once initiated, the sequence of write operations should not be interrupted. Resetting Software Data Protection WRITE DATA A0 TO ADDRESS 5555 WRITE DATA XX TO ANY ADDRESS WRITE LAST BYTE TO LAST ADDRESS BYTE/PAGE LOAD ENABLED OPTIONAL BYTE/PAGE LOAD OPERATION In the event the user wants to deactivate the software data protection feature for testing or reprogramming in an EEPROM programmer, the following six step algorithm will reset the internal protection circuit. After tWC, the X28HC256 will be in standard operating mode. Note: Once initiated, the sequence of write operations should not be interrupted. AFTER tWC RE-ENTERS DATA PROTECTED STATE FIGURE 13. WRITE SEQUENCE FOR SOFTWARE DATA PROTECTION FN8108 Rev 5.00 August 27, 2015 Page 13 of 19 X28HC256 VCC DATA ADDRESS AA 5555 55 2AAA 80 5555 AA 5555 55 2AAA 20 5555 tWC STANDARD OPERATING MODE CE WE FIGURE 14. RESET SOFTWARE DATA PROTECTION TIMING SEQUENCE System Considerations WRITE DATA AA TO ADDRESS 5555 WRITE DATA 55 TO ADDRESS 2AAA WRITE DATA 80 TO ADDRESS 5555 WRITE DATA AA TO ADDRESS 5555 WRITE DATA 55 TO ADDRESS 2AAA WRITE DATA 20 TO ADDRESS 5555 AFTER tWC, RE-ENTERS UNPROTECTED STATE Because the X28HC256 is frequently used in large memory arrays, it is provided with a two line control architecture for both read and write operations. Proper usage can provide the lowest possible power dissipation and eliminate the possibility of contention where multiple I/O pins share the same bus. To gain the most benefit, it is recommended that CE be decoded from the address bus and be used as the primary device selection input. Both OE and WE would then be common among all devices in the array. For a read operation, this assures that all deselected devices are in their standby mode and that only the selected device(s) is/are outputting data on the bus. Because the X28HC256 has two power modes, standby and active, proper decoupling of the memory array is of prime concern. Enabling CE will cause transient current spikes. The magnitude of these spikes is dependent on the output capacitive loading of the l/Os. Therefore, the larger the array sharing a common bus, the larger the transient spikes. The voltage peaks associated with the current transients can be suppressed by the proper selection and placement of decoupling capacitors. As a minimum, it is recommended that a 0.1F high frequency ceramic capacitor be used between VCC and VSS at each device. Depending on the size of the array, the value of the capacitor may have to be larger. In addition, it is recommended that a 4.7F electrolytic bulk capacitor be placed between VCC and VSS for each eight devices employed in the array. This bulk capacitor is employed to overcome the voltage droop caused by the inductive effects of the PC board traces. FIGURE 15. WRITE SEQUENCE FOR RESETTING SOFTWARE DATA PROTECTION FN8108 Rev 5.00 August 27, 2015 Page 14 of 19 X28HC256 Revision History The revision history provided is for informational purposes only and is believed to be accurate, but not warranted. Please go to the web to make sure that you have the latest revision. DATE REVISION CHANGE August 27, 2015 FN8108.5 Removed the reference to Military part under "Recommended Operating Conditions" and "Thermal Information" Removed X28HC256J-15, X28HC256SI-15, X28HC256SIZ-15, X28HC256J-12, X28HC256S-12, and X28HC256S-90 from the Ordering Information table on page 2. Updated Pin Description table on page 3. March 31, 2015 FN8108.4 -Updated entire datasheet to Intersil new standard. -Added revision history and about Intersil verbiage. -Third paragraph on page 1 updated From: Endurance for the X28HC256 is specified as a minimum 1,000,000 write cycles per byte and an inherent data retention of 100 years. To: Endurance for the X28HC256 is specified as a minimum 100,000 write cycles per byte and an inherent data retention of 100 years. -Features section on page 1 updated From: Highly reliable Direct WriteTM cell - Endurance: 1,000,000 cycles To: Highly reliable Direct WriteTM cell - Endurance: 100,000 cycles "Endurance and Data Retention" on page 4 updated Endurance from 1,000,000 to 100,000. -Ordering information table on page 2: Removed obsolete part numbers X28HC256P-15, X28HC256PI-15, X28HC256P-12, X28HC256PI-12, X28HC256P-90. -Ordering information table on page 2 updated the "Access time' section. Thermal Information table on page 4 updated "Temperature Under Bias" section for X28HC256 value from 10C to +85C to -10C to +85C. "DC Electrical Specifications" on page 4, added a note to Min and Max values. Removed note in Electrical Spec Table that referenced an obsolete part. About Intersil Intersil Corporation is a leading provider of innovative power management and precision analog solutions. The company's products address some of the largest markets within the industrial and infrastructure, mobile computing and high-end consumer markets. For the most updated datasheet, application notes, related documentation and related parts, please see the respective product information page found at www.intersil.com. You may report errors or suggestions for improving this datasheet by visiting www.intersil.com/ask. Reliability reports are also available from our website at www.intersil.com/support FN8108 Rev 5.00 August 27, 2015 Page 15 of 19 X28HC256 Small Outline Plastic Packages (SOIC) M28.3 (JEDEC MS-013-AE ISSUE C) N 28 LEAD WIDE BODY SMALL OUTLINE PLASTIC PACKAGE INDEX AREA H 0.25(0.010) M B M INCHES E SYMBOL -B- 1 2 3 L SEATING PLANE -A- A D h x 45o a e A1 B C 0.10(0.004) 0.25(0.010) M C A M B S MAX MILLIMETERS MIN MAX NOTES A 0.0926 0.1043 2.35 2.65 - A1 0.0040 0.0118 0.10 0.30 - B 0.013 0.0200 0.33 0.51 9 C 0.0091 0.0125 0.23 0.32 - D 0.6969 0.7125 17.70 18.10 3 E 0.2914 0.2992 7.40 7.60 4 e -C- MIN 0.05 BSC h 0.01 0.029 0.25 0.75 5 L 0.016 0.050 0.40 1.27 6 10.00 - 0.394 N 0.419 1.27 BSC H 28 0o 10.65 - 28 8o 0o 7 8o Rev. 1, 1/13 NOTES: 1. Symbols are defined in the "MO Series Symbol List" in Section 2.2 of Publication Number 95. 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. 3. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion and gate burrs shall not exceed 0.15mm (0.006 inch) per side. TYPICAL RECOMMENDED LAND PATTERN (1.50mm) 4. Dimension "E" does not include interlead flash or protrusions. Interlead flash and protrusions shall not exceed 0.25mm (0.010 inch) per side. 5. The chamfer on the body is optional. If it is not present, a visual index feature must be located within the crosshatched area. (9.38mm) 6. "L" is the length of terminal for soldering to a substrate. 7. "N" is the number of terminal positions. 8. Terminal numbers are shown for reference only. 9. The lead width "B", as measured 0.36mm (0.014 inch) or greater above the seating plane, shall not exceed a maximum value of 0.61mm (0.024 inch) (1.27mm TYP) FN8108 Rev 5.00 August 27, 2015 (0.51mm TYP) 10. Controlling dimension: MILLIMETER. Converted inch dimensions are not necessarily exact. Page 16 of 19 X28HC256 Plastic Leaded Chip Carrier Packages (PLCC) 0.042 (1.07) 0.048 (1.22) PIN (1) IDENTIFIER 0.042 (1.07) 0.056 (1.42) 0.004 (0.10) 0.050 (1.27) TP 0.025 (0.64) R 0.045 (1.14) ND CL C D2/E2 E1 E C L D2/E2 NE VIEW "A" A1 A D1 D 0.015 (0.38) MIN SEATING -C- PLANE 0.020 (0.51) MAX 3 PLCS 0.026 (0.66) 0.032 (0.81) 0.050 (1.27) MIN N32.45x55 (JEDEC MS-016AE ISSUE A) 32 LEAD PLASTIC LEADED CHIP CARRIER PACKAGE INCHES MILLIMETERS SYMBOL MIN MAX MIN MAX NOTES A 0.125 0.140 3.18 3.55 - A1 0.060 0.095 1.53 2.41 - D 0.485 0.495 12.32 12.57 - D1 0.447 0.453 11.36 11.50 3 D2 0.188 0.223 4.78 5.66 4, 5 E 0.585 0.595 14.86 15.11 - E1 0.547 0.553 13.90 14.04 3 E2 0.238 0.273 6.05 6.93 4, 5 N 28 28 6 ND 7 7 7 NE 9 9 7 Rev. 0 7/98 NOTES: 1. Controlling dimension: INCH. Converted millimeter dimensions are not necessarily exact. 2. Dimensions and tolerancing per ANSI Y14.5M-1982. 0.013 (0.33) 0.021 (0.53) 0.025 (0.64) MIN (0.12) M A S -B S D S 0.005 VIEW "A" TYP. 3. Dimensions D1 and E1 do not include mold protrusions. Allowable mold protrusion is 0.010 inch (0.25mm) per side. Dimensions D1 and E1 include mold mismatch and are measured at the extreme material condition at the body parting line. 4. To be measured at seating plane -C- contact point. 5. Centerline to be determined where center leads exit plastic body. 6. "N" is the number of terminal positions. 7. ND denotes the number of leads on the two shorts sides of the package, one of which contains pin #1. NE denotes the number of leads on the two long sides of the package. FN8108 Rev 5.00 August 27, 2015 Page 17 of 19 X28HC256 Small Outline Package Family (SO) A D h X 45 (N/2)+1 N A PIN #1 I.D. MARK E1 E c SEE DETAIL "X" 1 (N/2) B L1 0.010 M C A B e H C A2 GAUGE PLANE SEATING PLANE A1 0.004 C 0.010 M C A B L b 0.010 4 4 DETAIL X MDP0027 SMALL OUTLINE PACKAGE FAMILY (SO) INCHES SYMBOL SO-14 SO16 (0.300") (SOL-16) SO20 (SOL-20) SO24 (SOL-24) SO28 (SOL-28) TOLERANCE NOTES A 0.068 0.068 0.068 0.104 0.104 0.104 0.104 MAX - A1 0.006 0.006 0.006 0.007 0.007 0.007 0.007 0.003 - A2 0.057 0.057 0.057 0.092 0.092 0.092 0.092 0.002 - b 0.017 0.017 0.017 0.017 0.017 0.017 0.017 0.003 - c 0.009 0.009 0.009 0.011 0.011 0.011 0.011 0.001 - D 0.193 0.341 0.390 0.406 0.504 0.606 0.704 0.004 1, 3 E 0.236 0.236 0.236 0.406 0.406 0.406 0.406 0.008 - E1 0.154 0.154 0.154 0.295 0.295 0.295 0.295 0.004 2, 3 e 0.050 0.050 0.050 0.050 0.050 0.050 0.050 Basic - L 0.025 0.025 0.025 0.030 0.030 0.030 0.030 0.009 - L1 0.041 0.041 0.041 0.056 0.056 0.056 0.056 Basic - h 0.013 0.013 0.013 0.020 0.020 0.020 0.020 Reference - 16 20 24 28 Reference - N SO-8 SO16 (0.150") 8 14 16 NOTES: Rev. M 2/07 1. Plastic or metal protrusions of 0.006" maximum per side are not included. 2. Plastic interlead protrusions of 0.010" maximum per side are not included. 3. Dimensions "D" and "E1" are measured at Datum Plane "H". 4. Dimensioning and tolerancing per ASME Y14.5M-1994 FN8108 Rev 5.00 August 27, 2015 Page 18 of 19 X28HC256 Dual-In-Line Plastic Packages (PDIP) E28.6 (JEDEC N INDEX AREA 1 2 3 INCHES N/2 -B- -AD E BASE PLANE -C- SEATING PLANE A2 A L D1 e B1 D1 A1 eC B 0.010 (0.25) M MS-011-AB ISSUE B) 28 LEAD DUAL-IN-LINE PLASTIC PACKAGE E1 C A B S MILLIMETERS SYMBOL MIN MAX MIN MAX NOTES A - 0.250 - 6.35 4 A1 0.015 - 0.39 - 4 A2 0.125 0.195 3.18 4.95 - B 0.014 0.022 0.356 0.558 - C L B1 0.030 0.070 0.77 1.77 8 eA C 0.008 0.015 C D 1.380 1.565 eB NOTES: 1. Controlling Dimensions: INCH. In case of conflict between English and Metric dimensions, the inch dimensions control. 0.204 0.381 35.1 - 39.7 5 - 5 D1 0.005 - 0.13 E 0.600 0.625 15.24 15.87 6 E1 0.485 0.580 12.32 14.73 5 e 0.100 BSC 2.54 BSC - 2. Dimensioning and tolerancing per ANSI Y14.5M-1982. eA 0.600 BSC 15.24 BSC 6 3. Symbols are defined in the "MO Series Symbol List" in Section 2.2 of Publication No. 95. eB - 0.700 - 17.78 7 4. Dimensions A, A1 and L are measured with the package seated in JEDEC seating plane gauge GS-3. L 0.115 0.200 2.93 5.08 4 N 28 5. D, D1, and E1 dimensions do not include mold flash or protrusions. Mold flash or protrusions shall not exceed 0.010 inch (0.25mm). 6. E and eA are measured with the leads constrained to be perpendicular to datum -C- . 28 9 Rev. 1 12/00 7. eB and eC are measured at the lead tips with the leads unconstrained. eC must be zero or greater. 8. B1 maximum dimensions do not include dambar protrusions. Dambar protrusions shall not exceed 0.010 inch (0.25mm). 9. N is the maximum number of terminal positions. 10. Corner leads (1, N, N/2 and N/2 + 1) for E8.3, E16.3, E18.3, E28.3, E42.6 will have a B1 dimension of 0.030 - 0.045 inch (0.76 - 1.14mm). (c) Copyright Intersil Americas LLC 2005-2015. All Rights Reserved. All trademarks and registered trademarks are the property of their respective owners. For additional products, see www.intersil.com/en/products.html Intersil products are manufactured, assembled and tested utilizing ISO9001 quality systems as noted in the quality certifications found at www.intersil.com/en/support/qualandreliability.html Intersil products are sold by description only. Intersil may modify the circuit design and/or specifications of products at any time without notice, provided that such modification does not, in Intersil's sole judgment, affect the form, fit or function of the product. Accordingly, the reader is cautioned to verify that datasheets are current before placing orders. Information furnished by Intersil is believed to be accurate and reliable. However, no responsibility is assumed by Intersil or its subsidiaries for its use; nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Intersil or its subsidiaries. For information regarding Intersil Corporation and its products, see www.intersil.com FN8108 Rev 5.00 August 27, 2015 Page 19 of 19