X28C256 X28C256 256K 32K x 8 Bit 5 Volt, Byte Alterable E2PROM FEATURES DESCRIPTION • • The X28C256 is an 32K x 8 E2PROM, fabricated with Xicor’s proprietary, high performance, floating gate CMOS technology. Like all Xicor programmable nonvolatile memories the X28C256 is a 5V only device. The X28C256 features the JEDEC approved pinout for bytewide memories, compatible with industry standard RAMs. • • • • • Access Time: 200ns Simple Byte and Page Write — Single 5V Supply —No External High Voltages or VPP Control Circuits — Self-Timed —No Erase Before Write —No Complex Programming Algorithms —No Overerase Problem Low Power CMOS: —Active: 60mA —Standby: 200µA Software Data Protection — Protects Data Against System Level Inadvertent Writes High Speed Page Write Capability Highly Reliable Direct Write™ Cell — Endurance: 100,000 Write Cycles — Data Retention: 100 Years Early End of Write Detection — DATA Polling —Toggle Bit Polling The X28C256 supports a 64-byte page write operation, effectively providing a 78µs/byte write cycle and enabling the entire memory to be typically written in less than 2.5 seconds. The X28C256 also features DATA and Toggle Bit Polling, a system software support scheme used to indicate the early completion of a write cycle. In addition, the X28C256 includes a user-optional software data protection mode that further enhances Xicor’s hardware write protect capability. Xicor E2PROMs are designed and tested for applications requiring extended endurance. Inherent data retention is greater than 100 years. PIN CONFIGURATION 5 24 A4 6 A3 7 22 A2 8 21 A1 9 20 23 X28C256 A13 1 32 31 30 WE 2 TSOP A6 5 29 A8 A5 6 28 A9 A4 7 27 A11 A3 8 26 NC OE A2 9 25 OE A10 CE A1 10 24 A10 A0 11 23 CE I/O7 I/O6 NC 12 22 I/O7 I/O6 A13 A8 A9 A11 A0 I/O0 I/O1 10 19 11 18 12 17 I/O2 VSS 13 16 I/O5 I/04 14 15 I/O3 I/O0 X28C256 13 21 14 15 16 17 18 19 20 A2 A1 A0 I/O0 I/O1 I/O2 NC VSS NC I/O3 I/O4 I/O5 I/O6 I/O7 CE A10 I/O5 A5 NC 25 3 I/O3 I/O4 26 4 A14 3 A6 4 NC A7 VCC WE A12 27 VSS 28 2 A7 1 A12 I/O1 I/O2 A14 VCC LCC PLCC PLASTIC DIP CERDIP FLAT PACK SOIC 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 X28C256 32 31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 A3 A4 A5 A6 A7 A12 A14 NC VCC NC WE A13 A8 A9 A11 OE 3855 ILL F23 3855 FHD F03 3855 FHD F02 © Xicor, Inc. 1991, 1995 Patents Pending 3855-1.9 8/1/97 T1/C0/D8 EW 1 Characteristics subject to change without notice X28C256 PIN DESCRIPTIONS PIN NAMES Addresses (A0–A14) Symbol A0–A14 I/O0–I/O7 WE CE OE VCC VSS NC The Address inputs select an 8-bit memory location during a read or write operation. Chip Enable (CE) The Chip Enable input must be LOW to enable all read/ write operations. When CE is HIGH, power consumption is reduced. Output Enable (OE) Description Address Inputs Data Input/Output Write Enable Chip Enable Output Enable +5V Ground No Connect The Output Enable input controls the data output buffers and is used to initiate read operations. 3855 PGM T01 PIN CONFIGURATION Data In/Data Out (I/O0–I/O7) PGA Data is written to or read from the X28C256 through the I/O pins. I/O1 I/O2 I/O3 I/O5 I/O6 12 13 15 17 18 Write Enable (WE) I/O0 A0 11 10 The Write Enable input controls the writing of data to the X28C256. A1 9 A3 7 A5 5 A6 4 VSS I/O4 I/O7 14 16 19 A2 8 A4 X28C256 6 A12 2 A7 3 CE 20 A10 21 OE 22 A11 23 VCC A9 28 24 A14 1 WE 27 A8 25 A13 26 3855 FHD F04 BOTTOM VIEW FUNCTIONAL DIAGRAM X BUFFERS LATCHES AND DECODER 256K-BIT E2PROM ARRAY A0–A14 ADDRESS INPUTS Y BUFFERS LATCHES AND DECODER I/O BUFFERS AND LATCHES I/O0–I/O7 DATA INPUTS/OUTPUTS CE OE WE CONTROL LOGIC AND TIMING VCC VSS 3855 FHD F01 2 X28C256 DEVICE OPERATION Write Operation Status Bits Read The X28C256 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 1. 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. Figure 1. Status Bit Assignment Write I/O Write operations are initiated when both CE and WE are LOW and OE is HIGH. The X28C256 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 5ms. DP TB 5 4 3 2 1 0 RESERVED TOGGLE BIT DATA POLLING 3855 FHD F11 DATA Polling (I/O7) The X28C256 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 X28C256, eliminating 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. Note: If the X28C256 is in the protected state and an illegal write operation is attempted DATA Polling will not operate. Page Write Operation The page write feature of the X28C256 allows the entire memory to be written in 2.5 seconds. Page write allows two to sixty-four bytes of data to be consecutively written to the X28C256 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 (A6 through A14) for each subsequent valid write cycle to the part during this operation must be the same as the initial page address. Toggle Bit (I/O6) 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 sixty-three 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 100µs of the falling edge of the preceding WE. If a subsequent WE HIGH to LOW transition is not detected within 100µs, 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 100µs. The X28C256 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 LOW to HIGH 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 or write operations. 3 X28C256 DATA POLLING I/O7 Figure 2. DATA Polling Bus Sequence WE LAST WRITE CE OE VIH A0–A14 VOH HIGH Z I/O7 VOL An An An X28C256 READY An An An An 3855 FHD F12 Figure 3. DATA Polling Software Flow DATA Polling can effectively halve the time for writing to the X28C256. The timing diagram in Figure 2 illustrates the sequence of events on the bus. The software flow diagram in Figure 3 illustrates one method of implementing the routine. WRITE DATA NO WRITES COMPLETE? YES SAVE LAST DATA AND ADDRESS READ LAST ADDRESS IO7 COMPARE? NO YES X28C256 READY 3855 FHD F13 4 X28C256 THE TOGGLE BIT I/O6 Figure 4. Toggle Bit Bus Sequence WE LAST WRITE CE OE VOH I/O6 * HIGH Z VOL * X28C256 READY * Beginning and ending state of I/O6 will vary. 3855 FHD F14 Figure 5. Toggle Bit Software Flow The Toggle Bit can eliminate the software housekeeping chore of saving and fetching the last address and data written to a device in order to implement DATA Polling. This can be especially helpful in an array comprised of multiple X28C256 memories that is frequently updated. The timing diagram in Figure 4 illustrates the sequence of events on the bus. The software flow diagram in Figure 5 illustrates a method for polling the Toggle Bit. LAST WRITE LOAD ACCUM FROM ADDR n COMPARE ACCUM WITH ADDR n COMPARE OK? NO YES X28C256 READY 3855 FHD F15 5 X28C256 HARDWARE DATA PROTECTION The X28C256 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. The X28C256 provides three hardware features (compatible with X28C64) that protect nonvolatile data from inadvertent writes. • Noise Protection—A WE pulse typically less than 20ns will not initiate a write cycle. • 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. Once the software protection is enabled, the X28C256 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 DATA PROTECTION Software Algorithm The X28C256 offers a software controlled data protection feature. The X28C256 is shipped from Xicor 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. 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 Figure 6 and 7 for the sequence. The three-byte sequence opens the page write window enabling the host to write from one to sixty-four bytes of data.* Once the page load cycle has been completed, the device will automatically be returned to the data protected state. *Note: Once the three-byte sequence is issued it must be followed by a valid byte or page write operation. 6 X28C256 SOFTWARE DATA PROTECTION Figure 6. Timing Sequence—Byte or Page Write VCC (VCC) 0V DATA ADDR. AA 5555 55 2AAA A0 5555 tWPH2 CE ≤tBLC MAX WE WRITES OK tWC WRITE PROTECTED BYTE OR PAGE 3855 FHD F16 Figure 7. Write Sequence for Software Data Protection 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 X28C256 will automatically disable further writes unless another command is issued to cancel it. If no further commands are issued the X28C256 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. WRITE DATA A0 TO ADDRESS 5555 BYTE/PAGE LOAD ENABLED WRITE DATA XX TO ANY ADDRESS WRITE LAST BYTE TO LAST ADDRESS AFTER tWC RE-ENTERS DATA PROTECTED STATE 3855 FHD F17 7 X28C256 RESETTING SOFTWARE DATA PROTECTION Figure 8. Reset Software Data Protection Timing Sequence VCC DATA AA ADDR. 5555 55 2AAA 80 5555 AA 5555 55 2AAA 20 5555 ≥tWC STANDARD OPERATING MODE CE WE 3855 FHD F18 Figure 9. Software Sequence to Deactivate Software Data Protection In the event the user wants to deactivate the software data protection feature for testing or reprogramming in an E2PROM programmer, the following six step algorithm will reset the internal protection circuit. After tWC, the X28C256 will be in standard operating mode. WRITE DATA AA TO ADDRESS 5555 Note: 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 3855 FHD F19 8 Once initiated, the sequence of write operations should not be interrupted. X28C256 prime concern. Enabling CE will cause transient current spikes. The magnitude of these spikes is dependent on the output capacitive loading of the I/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 0.1µF 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. SYSTEM CONSIDERATIONS Because the X28C256 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 outputting data on the bus. In addition, it is recommended that a 4.7µF 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. Because the X28C256 has two power modes, standby and active, proper decoupling of the memory array is of Normalized Standby Supply Current vs. Ambient Temperature Normalized Active Supply Current vs. Ambient Temperature 1.4 1.4 VCC = 5V NORMALIZED ISB1 NORMALIZED ICC VCC = 5V 1.2 1.0 0.8 1.2 1.0 0.8 0.6 0.6 –55 –55 +25 +125 AMBIENT TEMPERATURE (°C) +25 +125 AMBIENT TEMPERATURE (°C) 3855 FHD F20.1 3855 FHD F21.1 9 X28C256 ABSOLUTE MAXIMUM RATINGS* Temperature under Bias X28C256 ...................................... –10°C to +85°C X28C256I, X28C256M ............... –65°C to +135°C Storage Temperature ....................... –65°C to +150°C Voltage on any Pin with Respect to VSS ....................................... –1V to +7V D.C. Output Current ............................................. 5mA Lead Temperature (Soldering, 10 seconds) .............................. 300°C *COMMENT Stresses above those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and the functional operation of the device at these or any other conditions above those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. RECOMMENDED OPERATING CONDITIONS Temperature Min. Max. Supply Voltage Limits Commercial Industrial Military 0°C –40°C –55°C +70°C +85°C +125°C X28C256 5V ±10% 3855 PGM T03.1 3855 PGM T02.1 D.C. OPERATING CHARACTERISTICS (over recommended operating conditions, unless otherwise specified) Limits Symbol Parameter Min. Typ.(1) Max. Units Test Conditions CE = OE = VIL, WE = VIH, All I/O’s = Open, Address Inputs = .4V/2.4V @ f = 5MHz CE = VIH, OE = VIL All I/O’s = Open, Other Inputs = VIH CE = VCC – 0.3V, OE = VIL All I/O’s = Open, Other Inputs = VCC – 0.3V VIN = VSS to VCC VOUT = VSS to VCC, CE = VIH ICC VCC Current (Active) (TTL Inputs) 30 60 mA ISB1 VCC Current (Standby) (TTL Inputs) VCC Current (Standby) (CMOS Inputs) 1 2 mA 200 500 µA 10 10 0.8 VCC + 1 0.4 µA µA V V V V ISB2(2) ILI ILO VlL(3) VIH(3) VOL VOH Input Leakage Current Output Leakage Current Input LOW Voltage Input HIGH Voltage Output LOW Voltage Output HIGH Voltage –1 2 2.4 IOL = 2.1mA IOH = –400µA 3855 PGM T04.2 Notes: (1) (2) (3) Typical values are for TA = 25°C and nominal supply voltage and are not tested ISB2 max. of 200µA available from Xicor. Contact local sales office and reference X28C256 C7125. VIL min. and VIH max. are for reference only and are not tested. 10 X28C256 ENDURANCE AND DATA RETENTION Parameter Min. Units Endurance Data Retention 100,000 100 Cycles Years 3855 PGM T05.3 POWER-UP TIMING Symbol (4) tPUR tPUW(4) Parameter Max. Units Power-up to Read Operation Power-up to Write Operation 100 5 µs ms 3855 PGM T06 CAPACITANCE TA = +25°C, f = 1MHz, VCC = 5V Symbol Parameter CI/O(4) CIN(4) Input/Output Capacitance Input Capacitance Max. Units Test Conditions 10 6 pF pF VI/O = 0V VIN = 0V 3855 PGM T07.1 A.C. CONDITIONS OF TEST Input Pulse Levels MODE SELECTION 0V to 3V Input Rise and Fall Times Input and Output Timing Levels 10ns CE L L H OE L H X WE H L X X X L X X H 1.5V 3855 PGM T08.1 Mode Read Write Standby and Write Inhibit Write Inhibit Write Inhibit I/O DOUT DIN High Z Power Active Active Standby — — — — 3855 PGM T09 Note: (4) This parameter is periodically sampled and not 100% tested. EQUIVALENT A.C. LOAD CIRCUIT SYMBOL TABLE 5V WAVEFORM 1.92KΩ OUTPUT 1.37KΩ 100pF 3855 FHD F22.3 11 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 N/A Changing: State Not Known Center Line is High Impedance X28C256 A.C. CHARACTERISTICS (over recommended operating conditions, unless otherwise specified) Read Cycle Limits X28C256-20 X28C256-25 Symbol Parameter Min. tRC tCE tAA tOE tLZ(5) tOLZ(5) tHZ(5) tOHZ(5) tOH Read Cycle Time Chip Enable Access Time Address Access Time Output Enable Access Time CE LOW to Active Output OE LOW to Active Output CE HIGH to High Z Output OE HIGH to High Z Output Output Hold from Address Change 200 Max. Min. Max. 250 200 200 80 0 0 Min. Max. 300 250 250 100 0 0 50 50 0 X28C256 300 300 100 0 0 50 50 0 50 50 0 Units ns ns ns ns ns ns ns ns ns 3855 PGM T10.1 Read Cycle tRC ADDRESS tCE CE tOE OE VIH WE tOLZ tOHZ tLZ DATA I/O HIGH Z tOH DATA VALID tHZ DATA VALID tAA 3855 FHD F05 Note: (5) tLZ min., tHZ, tOLZ min., and tOHZ are peridocally sampled and not 100% tested. tHZ and tOHZ are measured, with CL = 5pF, from the point when CE or OE return HIGH (whichever occurs first) to the time when the outputs are no longer driven. 12 X28C256 WRITE CYCLE LIMITS Symbol Parameter tWC(7) tAS tAH tCS tCH tCW tOES tOEH tWP tWPH tWPH2(8) tDV tDS tDH tDW tBLC(9) Write Cycle Time Address Setup Time Address Hold Time Write Setup Time Write Hold Time CE Pulse Width OE HIGH Setup Time OE HIGH Hold Time WE Pulse Width WE HIGH Recovery SDP WE Recovery Data Valid Data Setup Data Hold Delay to Next Write Byte Load Cycle Min.(9) Typ.(6) Max. Units 5 10 ms ns ns ns ns ns ns ns ns ns µs µs ns ns µs µs 0 150 0 0 100 10 10 100 50 1 1 50 10 10 1 100 3855 PGM T11.1 WE Controlled Write Cycle tWC ADDRESS tAS tAH tCS tCH CE OE tOES tOEH tWP WE tDV DATA IN DATA VALID tDS DATA OUT tDH HIGH Z 3855 FHD F06 Notes: (6) Typical values are for TA = 25°C and nominal supply voltage. (7) 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. (8) tWPH is the normal page write operation WE recovery time. tWPH2 is the WE recovery time needed only after the end of issuing the three-byte SDP command sequence and before writing the first byte of data to the array. Refer to Figure 6 which illustrates the tWPH2 requirement. (9) For faster tWC and tBLC, refer to X28HC256 or X28VC256. 13 X28C256 CE Controlled Write Cycle tWC ADDRESS tAS tAH tCW CE tOES OE tOEH tCS tCH WE tDV DATA IN DATA VALID tDS tDH HIGH Z DATA OUT 3855 FHD F07 Page Write Cycle (10) OE CE tWP tBLC WE tWPH ADDRESS* (11) I/O LAST BYTE BYTE 0 BYTE 1 BYTE 2 BYTE n BYTE n+1 BYTE n+2 tWC *For each successive write within the page write operation, A6–A14 should be the same or writes to an unknown address could occur. 3855 FHD F08 Notes: (10) 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. (11) 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. 14 X28C256 DATA Polling Timing Diagram(12) ADDRESS An An An CE WE tOEH tOES OE tDW DIN=X I/O7 DOUT=X DOUT=X tWC 3855 FHD F09 Toggle Bit Timing Diagram(12) CE WE tOES tOEH OE tDW I/O6 HIGH Z * * tWC * Starting and ending state of I/O6 will vary, depending upon actual tWC. 3855 FHD F10 Note: (12) Polling operations are by definition read cycles and are therefore subject to read cycle timings. 15 X28C256 PACKAGING INFORMATION 28-LEAD PLASTIC DUAL IN-LINE PACKAGE TYPE P 1.470 (37.34) 1.400 (35.56) 0.557 (14.15) 0.510 (12.95) PIN 1 INDEX PIN 1 0.085 (2.16) 0.040 (1.02) 1.300 (33.02) REF. 0.160 (4.06) 0.125 (3.17) SEATING PLANE 0.030 (0.76) 0.015 (0.38) 0.160 (4.06) 0.120 (3.05) 0.110 (2.79) 0.090 (2.29) 0.065 (1.65) 0.040 (1.02) 0.022 (0.56) 0.014 (0.36) 0.625 (15.88) 0.590 (14.99) 0° 15° TYP. 0.010 (0.25) NOTE: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. PACKAGE DIMENSIONS EXCLUDE MOLDING FLASH 3926 FHD F04 16 X28C256 PACKAGING INFORMATION 28-LEAD HERMETIC DUAL IN-LINE PACKAGE TYPE D 1.490 (37.85) MAX. 0.610 (15.49) 0.500 (12.70) PIN 1 0.005 (0.127) MIN. 0.100 (2.54) MAX. SEATING PLANE 0.232 (5.90) MAX. 0.060 (1.52) 0.015 (0.38) 0.150 (3.81) MIN. 0.200 (5.08) 0.125 (3.18) 0.065 (1.65) 0.038 (0.97) TYP. 0.055 (1.40) 0.110 (2.79) 0.090 (2.29) TYP. 0.100 (2.54) 0.023 (0.58) 0.014 (0.36) TYP. 0.018 (0.46) 0.620 (15.75) 0.590 (14.99) TYP. 0.614 (15.60) 0° 15° 0.015 (0.38) 0.008 (0.20) NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 3926 FHD F08 17 X28C256 PACKAGING INFORMATION 32-LEAD PLASTIC LEADED CHIP CARRIER PACKAGE TYPE J 0.050" TYPICAL 0.420 (10.67) 0.030" TYPICAL 32 PLACES 0.050" TYPICAL 0.510" TYPICAL 0.400" 0.050 (1.27) TYP. 0.300" REF 0.410" FOOTPRINT 0.045 (1.14) x 45° 0.021 (0.53) 0.013 (0.33) TYP. 0.017 (0.43) 0.495 (12.57) 0.485 (12.32) TYP. 0.490 (12.45) 0.453 (11.51) 0.447 (11.35) TYP. 0.450 (11.43) 0.300 (7.62) REF. SEATING PLANE ±0.004 LEAD CO – PLANARITY — 0.015 (0.38) 0.095 (2.41) 0.060 (1.52) 0.140 (3.56) 0.100 (2.45) TYP. 0.136 (3.45) 0.048 (1.22) 0.042 (1.07) PIN 1 0.595 (15.11) 0.585 (14.86) TYP. 0.590 (14.99) 0.553 (14.05) 0.547 (13.89) TYP. 0.550 (13.97) 0.400 (10.16)REF. 3° TYP. NOTES: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. DIMENSIONS WITH NO TOLERANCE FOR REFERENCE ONLY 3926 FHD F13 18 X28C256 PACKAGING INFORMATION 32-PAD CERAMIC LEADLESS CHIP CARRIER PACKAGE TYPE E 0.300 (7.62) BSC 0.150 (3.81) BSC 0.015 (0.38) 0.003 (0.08) 0.020 (0.51) x 45° REF. 0.095 (2.41) 0.075 (1.91) PIN 1 0.022 (0.56) DIA. 0.006 (0.15) 0.200 (5.08) BSC 0.015 (0.38) MIN. 0.028 (0.71) 0.022 (0.56) (32) PLCS. 0.050 (1.27) BSC 0.055 (1.39) 0.045 (1.14) TYP. (4) PLCS. 0.040 (1.02) x 45° REF. TYP. (3) PLCS. 0.458 (11.63) 0.442 (11.22) 0.120 (3.05) 0.060 (1.52) 0.458 (11.63) –– 0.560 (14.22) 0.540 (13.71) 0.558 (14.17) –– 0.088 (2.24) 0.050 (1.27) 0.400 (10.16) BSC PIN 1 INDEX CORNER NOTE: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. TOLERANCE: ±1% NLT ±0.005 (0.127) 3926 FHD F14 19 X28C256 PACKAGING INFORMATION 28-LEAD CERAMIC FLAT PACK TYPE F 0.019 (0.48) 0.015 (0.38) PIN 1 INDEX 1 28 0.050 (1.27) BSC 0.740 (18.80) MAX. 0.045 (1.14) MAX. 0.440 (11.18) MAX. 0.006 (0.15) 0.003 (0.08) 0.370 (9.40) 0.250 (6.35) TYP. 0.300 2 PLCS. 0.180 (4.57) MIN. 0.130 (3.30) 0.090 (2.29) 0.045 (1.14) 0.025 (0.66) 0.030 (0.76) MIN. NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 3926 FHD F16 20 X28C256 PACKAGING INFORMATION 28-LEAD CERAMIC PIN GRID ARRAY PACKAGE TYPE K 12 13 15 17 18 11 10 14 16 19 A 0.008 (0.20) 9 8 20 21 7 6 22 23 0.050 (1.27) A 5 2 28 24 25 4 3 1 27 26 0.080 (2.03) 0.070 (1.78) TYP. 0.100 (2.54) ALL LEADS PIN 1 INDEX NOTE: LEADS 4,12,18 & 26 0.080 (2.03) 4 CORNERS 0.070 (1.78) 0.110 (2.79) 0.090 (2.29) 0.072 (1.83) 0.062 (1.57) 0.020 (0.51) 0.016 (0.41) 0.660 (16.76) 0.640 (16.26) A A 0.185 (4.70) 0.175 (4.44) 0.561 (14.25) 0.541 (13.75) NOTE: ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 3926 FHD F15 21 X28C256 PACKAGING INFORMATION 28-LEAD PLASTIC SMALL OUTLINE GULL WING PACKAGE TYPE S 0.299 (7.59) 0.290 (7.37) 0.419 (10.64) 0.394 (10.01) 0.020 (0.508) 0.014 (0.356) 0.713 (18.11) 0.697 (17.70) 0.105 (2.67) 0.092 (2.34) BASE PLANE SEATING PLANE 0.012 (0.30) 0.003 (0.08) 0.050 (1.270) BSC 0.050" TYPICAL 0.0200 (0.5080) X 45° 0.0100 (0.2540) 0.050" TYPICAL 0.013 (0.32) 0.008 (0.20) 0° – 8° 0.42" MAX 0.0350 (0.8890) 0.0160 (0.4064) FOOTPRINT 0.030" TYPICAL 28 PLACES NOTES: 1. ALL DIMENSIONS IN INCHES (IN PARENTHESES IN MILLIMETERS) 2. FORMED LEAD SHALL BE PLANAR WITH RESPECT TO ONE ANOTHER WITHIN 0.004 INCHES 3926 FHD F17 22 X28C256 PACKAGING INFORMATION 32-LEAD THIN SMALL OUTLINE PACKAGE (TSOP) TYPE T SEE NOTE 2 12.50 (0.492) 12.30 (0.484) PIN #1 IDENT. O 0.76 (0.03) 0.50 (0.0197) BSC SEE NOTE 2 8.02 (0.315) 7.98 (0.314) 0.26 (0.010) 0.14 (0.006) 1.18 (0.046) 1.02 (0.040) 0.17 (0.007) 0.03 (0.001) SEATING PLANE 0.58 (0.023) 0.42 (0.017) 14.15 (0.557) 13.83 (0.544) 14.80 ± 0.05 (0.583 ± 0.002) SOLDER PADS 0.30 ± 0.05 (0.012 ± 0.002) TYPICAL 32 PLACES 15 EQ. SPC. 0.50 ± 0.04 0.0197 ± 0.016 = 7.50 ± 0.06 (0.295 ± 0.0024) OVERALL TOL. NON-CUMULATIVE 0.17 (0.007) 0.03 (0.001) 1.30 ± 0.05 (0.051 ± 0.002) 0.50 ± 0.04 (0.0197 ± 0.0016) FOOTPRINT NOTE: 1. ALL DIMENSIONS ARE SHOWN IN MILLIMETERS (INCHES IN PARENTHESES). 23 3926 ILL F38.1 X28C256 ORDERING INFORMATION X28C256 X X -X Access Time –20 = 200ns –25 = 250ns Blank = 300ns –35 = 350ns Device Temperature Range Blank = Commercial = 0°C to +70°C I = Industrial = –40°C to +85°C M = Military = –55°C to +125°C MB = MIL-STD-883 Package P = 28-Lead Plastic DIP D = 28-Lead Cerdip J = 32-Lead PLCC E = 32-Pad LCC F = 28-Lead Flat Pack K = 28-Lead Pin Grid Array S = 28-Lead Plastic SOIC T = 32-Lead TSOP LIMITED WARRANTY Devices sold by Xicor, Inc. are covered by the warranty and patent indemnification provisions appearing in its Terms of Sale only. Xicor, Inc. makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. Xicor, Inc. makes no warranty of merchantability or fitness for any purpose. Xicor, Inc. reserves the right to discontinue production and change specifications and prices at any time and without notice. Xicor, Inc. assumes no responsibility for the use of any circuitry other than circuitry embodied in a Xicor, Inc. product. No other circuits, patents, licenses are implied. U.S. PATENTS Xicor products are covered by one or more of the following U.S. Patents: 4,263,664; 4,274,012; 4,300,212; 4,314,265; 4,326,134; 4,393,481; 4,404,475; 4,450,402; 4,486,769; 4,488,060; 4,520,461; 4,533,846; 4,599,706; 4,617,652; 4,668,932; 4,752,912; 4,829, 482; 4,874, 967; 4,883, 976. Foreign patents and additional patents pending. LIFE RELATED POLICY In situations where semiconductor component failure may endanger life, system designers using this product should design the system with appropriate error detection and correction, redundancy and back-up features to prevent such an occurence. Xicor's products are not authorized for use in critical components in life support devices or systems. 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 2. A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. 24