28C256T 256K EEPROM (32K x 8-Bit) EEPROM DATA INPUTS/OUTPUTS I/O0 - I/O7 VCC GND OE WE OE, CE, and WE LOGIC CE Y DECODER ADDRESS INPUTS DATA LATCH INPUT/OUTPUT BUFFERS Y-GATING CELL MATRIX X DECODER IDENTIFICATION Logic Diagram DESCRIPTION: • RAD-PAK® radiation-hardened against natural space radiation • Total dose hardness: - > 100 Krad (Si), dependent upon space mission • Excellent Single Event Effects: - SELTH LET: > 120 MeV/mg/cm2 - SEUTH LET (read mode): > 90 MeV/mg/cm2 - SEUTH LET (write mode): > 18 MeV/mg/cm2 • Package: - 28 pin RAD-PAK® flat pack - 28 pin RAD-PAK® DIP - JEDEC approved byte wide pinout • High Speed: - 120, 150 ns maximum access times available • High endurance: - 10,000 erase/write (in Page Mode), 10-year data retention • Page Write Mode: - 1 to 64 bytes • Low power dissipation: - 15 mA active current (cycle = 1 µ s) - 20 µ A standby current (CE = VCC) Maxwell Technologies’ 28C256T high density 256k-bit EEPROM microcircuit features a greater than 100 krad (Si) total dose tolerance, depending upon space mission. The 28C256T is capable of in-system electrical byte and page programmability. It has a 64-Byte page programming function to make its erase and write operations faster. It also features data polling to indicate the completion of erase and programming operations. Maxwell Technologies' patented RAD-PAK® packaging technology incorporates radiation shielding in the microcircuit package. It eliminates the need for box shielding while providing the required radiation shielding for a lifetime in orbit or space mission. In a GEO orbit, RAD-PAK provides greater than 100 krad (Si) radiation dose tolerance. This product is available with screening up to Class S. 02.18.02 Rev 5 (858) 503-3300 - Fax: (858) 503-3301- www.maxwell.com All data sheets are subject to change without notice 1 ©2001 Maxwell Technologies All rights reserved. Memory FEATURES: 28C256T 256K EEPROM (32K x 8-Bit) EEPROM TABLE 1. 28C256T PINOUT DESCRIPTION PIN SYMBOL DESCRIPTION *10-3, 25, 24, 21, 23, 2, 26, 1 A0-A14 11-13, 15-19 I/O0-I/O7 22 OE Output Enable 20 CE Chip Enable 27 WE Write Enable 28 VCC Power Supply 14 VSS Ground Address Input/Output *Refer to diagram on Page 1 for pin relationship. TABLE 2. 28C256T ABSOLUTE MAXIMUM RATINGS Supply Voltage (Relative to VSS) Input Voltage (Relative to VSS) Operating Temperature Range2 Storage Temperature Range SYMBOL MIN MAX UNITS VCC -0.6 7.0 V VIN -0.51 7.0 V TOPR -55 125 °C TSTG -65 150 °C Memory PARAMETER 1. VIN = -3.0 V for pulse width > 50 ns. 2. Including electrical characteristics and data retention. TABLE 3. 28C256T DELTA LIMITS PARAMETER VARIATION ICC1 ±10% ICC2 ±10% ICC3A ±10% ICC3B ±10% 02.18.02 Rev5 All data sheets are subject to change without notice 2 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM TABLE 4. 28C256T RECOMMENDED OPERATING CONDITIONS PARAMETER SUBGROUPS SYMBOL MIN MAX UNITS 1 VCC 4.5 5.5 V VIL VIH VH -0.31 2.2 VCC -0.5 0.8 VCC +0.3 VCC +1 V V V -- 0.87 °C/W -- 0.86 °C/W -55 125 °C Supply Voltage Input Voltage 1 1 1 Thermal Impedance — Flat Package 1 Thermal Impedance — DIP Package 1 ΘJC ΘJC Operating Temperature Range 1 TOPR 1. VIL min= -1.0V for pulse width < 50 ns. TABLE 5. 28C256T CAPACITANCE1 PARAMETER Input Capacitance: VIN = 0V 1 Output Capacitance: VOUT = 0V 1 SYMBOL MIN MAX UNITS CIN -- 6 pF COUT -- 12 pF Memory (TA = 25 ° C, f = 1 MHz) 1. Guaranteed by design. TABLE 6. 28C256T DC ELECTRICAL CHARACTERISTICS (VCC = 5 V ± 10%, TA = -55 TO +125 ° C UNLESS OTHERWISE SPECIFIED) PARAMETER CONDITIONS Input Leakage Current SUBGROUPS SYMBOL MIN MAX UNITS VCC = 5.5 V, VIN = 5.5 V 1, 2, 3 ILI -- 2 uA Output Leakage Current VCC = 5.5 V, VOUT = 5.5 V/0.4 V 1, 2, 3 ILO -- 2 uA Standby VCC Current CE = VCC 1, 2, 3 ICC1 -- 20 uA CE = VIH 1, 2, 3 ICC2 -- 1 mA IOUT = 0 mA Duty = 100% VCC = 5.5 V Cycle = 1 us 1, 2, 3 ICC3 -- 15 mA -- 50 Operating VCC Current IOUT = 0mA Duty = 100% VCC = 5.5 V Cycle = 150 ns Input Low Voltage 1, 2, 3 VIL -- 0.8 V Input High Voltage 1, 2, 3 VIH 2.2 -- V 1, 2, 3 VH VCC -0.5 -- V Output Low Voltage ILO = 2.1 mA 1, 2, 3 VOL -- 0.4 V Output High Voltage IOH = -400 uA 1, 2, 3 VOH 2.4 -- V 02.18.02 Rev5 All data sheets are subject to change without notice 3 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM TABLE 7. 28C256T AC ELECTRICAL CHARACTERISTICS FOR READ OPERATION1 (VCC = 5V ±10%, TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED) PARAMETER SUBGROUPS SYMBOL Address Access Time CE = OE = VIL, WE = VIH -120 -150 9, 10, 11 tACC CE to Output Delay OE = VIL, WE = VIH -120 -150 9, 10, 11 OE to Output Delay CE = VIL, WE = VIH -120 -150 9, 10, 11 Output Hold from Address CE = OE = VIL, WE = VIH -120 -150 9, 10, 11 OE (CE) High to Output Float CE = VIL, WE = VIH 2 -120 -150 9, 10, 11 MIN MAX --- 120 150 --- 120 150 0 0 75 75 0 0 --- 0 0 50 50 UNITS ns tCE ns tOE ns tOH ns ns 1. Test conditions: Input pulse levels - 0V to 3V; input rise and fall times < 20 ns; output load - 1 TTL gate + 100 pF (including scope and jig); reference levels for measuring timing - 0.8V/1.8V. 2. tDF and tDFR are defined as the time at which the output becomes an open circuit and data is no longer driven. TABLE 8. 28C256T AC ELECTRICAL CHARACTERISTICS FOR PAGE/BYTE ERASE AND WRITE OPERATIONS (VCC = 5V ±10%, TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED) PARAMETER Address Setup Time -120 -150 SUBGROUPS SYMBOL MIN1 TYP MAX 0 0 --- --- 0 0 --- --- 0 0 --- --- UNITS ns tAS 9, 10, 11 9, 10, 11 CE to Write Setup Time -120 -150 tCS 2 9, 10, 11 ns 9, 10, 11 WE to Write Setup Time -120 -150 tWS 3 9, 10, 11 ns 9, 10, 11 WE Hold Time -120 -150 9, 10, 11 tWH 3 ns 0 0 02.18.02 Rev5 --- All data sheets are subject to change without notice 4 ©2001 Maxwell Technologies All rights reserved. Memory tDF 28C256T 256K EEPROM (32K x 8-Bit) EEPROM TABLE 8. 28C256T AC ELECTRICAL CHARACTERISTICS FOR PAGE/BYTE ERASE AND WRITE OPERATIONS (VCC = 5V ±10%, TA = -55 TO 125 °C UNLESS OTHERWISE SPECIFIED) PARAMETER SUBGROUPS SYMBOL WE Pulse Width -120 -150 CE Pulse Width -120 -150 9, 10, 11 tWP 2 Address Hold Time -120 -150 9, 10, 11 Data Setup Time -120 -150 9, 10, 11 Data Hold Time -120 -150 9, 10, 11 Chip Enable Hold Time2 -120 -150 9, 10, 11 Output Enable to Write Setup Time -120 -150 9, 10, 11 Output Enable Hold Time -120 -150 9, 10, 11 Data Latch Time4 -120 -150 9, 10, 11 Write Cycle Time -120 -150 9, 10, 11 Byte Load Window4 -120 -150 9, 10, 11 Byte Load Cycle4 -120 -150 9, 10, 11 Write Start Time -120 -150 9, 10, 11 TYP MAX 200 250 --- --- 200 250 --- --- 150 150 --- --- 75 100 --- --- 10 10 --- --- 0 0 --- --- 0 0 --- --- 0 0 --- --- --- 230 280 --- --- --- 10 10 --- 100 100 --- 0.55 0.55 --- 30 30 150 150 --- --- UNITS ns tCW 3 ns tAH tDS ns ns tDH ns tCH tOES ns tOEH ns ns tDL ms tWC tBL us us tBLC ns tDW Use this device in a longer cycle than this value. WE controlled operation. CE controlled operation. Not tested. 02.18.02 Rev5 All data sheets are subject to change without notice 5 ©2001 Maxwell Technologies All rights reserved. Memory 1. 2. 3. 4. MIN1 28C256T 256K EEPROM (32K x 8-Bit) EEPROM TABLE 9. 28C256T MODE SELECTION 1 MODE CE OE WE I/O Write VIL VIL VIH DOUT Standby VH X X HIGH-Z Write VIL VIH VIL DIN Deselect VIL VIH VIH HIGH-Z Write Inhibit X X VIH -- X VIL X -- VIL VIL VIH DATA-OUT (I/O7) Data\ Polling 1. X = Does not matter. Memory 02.18.02 Rev5 All data sheets are subject to change without notice 6 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM FIGURE 1. READ TIMING WAVEFORM 02.18.02 Rev5 Memory FIGURE 2. BYTE WRITE TIMING WAVEFORM (1) (WE CONTROLLED) All data sheets are subject to change without notice 7 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM FIGURE 3. BYTE WRITE TIMING WAVEFORM (2) (CE CONTROLLED) Memory FIGURE 4. PAGE WRITE TIMING WAVEFORM (1) (WE CONTROLLED) 02.18.02 Rev5 All data sheets are subject to change without notice 8 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM FIGURE 5. PAGE WRITE TIMING WAVEFORM (2) (CE CONTROLLED) Memory FIGURE 6. DATA POLLING TIMING WAVEFORM 02.18.02 Rev5 All data sheets are subject to change without notice 9 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM EEPROM APPLICATION NOTES This application note describes the programming procedures for the EEPROM modules and the details of various techniques to preserve data protection. Automatic Page Write Page-mode write feature allows 1 to 64 bytes of data to be written into the EEPROM in a single write cycle, and allows the undefined data within 64 bytes to be written corresponding to the undefined address (A0 to A5). Loading the first byte of data, the data load window opens 30 µ s for the second byte. In the same manner each additional byte of data can be loaded within 30 µ s. In case CE and WE are kept high for 100(s after data input, EEPROM enters erase and write mode automatically and only the input data are written into the EEPROM. WE CE Pin Operation During a write cycle, addresses are latched by the falling edge of WE or CE, and data is latched by the rising edge of WE or CE. Data Polling Data Protection To protect the data during operation and power on/off, the EEPROM has the internal functions described below. 1. Data Protection against Noise of Control Pins (CE, OE, WE) during Operation. During readout or standby, noise on the control pins may act as a trigger and turn the EEPROM to programming mode by mistake. To prevent this phenomenon, the EEPROM has a noise cancellation function that cuts noise if its width is 20ns or less in programming mode. Be careful not to allow noise of a width of more than 20ns on the control pins. 02.18.02 Rev5 All data sheets are subject to change without notice 10 ©2001 Maxwell Technologies All rights reserved. Memory Data Polling function allows the status of the EEPROM to be determined. If EEPROM is set to read mode during a write cycle, an inversion of the last byte of data to be loaded outputs from I/O 7 to indicate that the EEPROM is performing a write operation. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM Memory 28 PIN RAD-PAK® FLAT PACKAGE DIMENSION SYMBOL MIN NOM MAX A 0.165 0.177 0.189 b 0.015 0.017 0.022 c 0.003 0.005 0.009 D -- 0.720 0.740 E 0.380 0.410 0.420 E1 -- -- 0.440 E2 0.180 0.240 -- E3 0.030 0.085 -- e 0.050 BSC L 0.390 0.400 0.410 Q 0.040 0.050 0.053 S1 0.005 0.027 -- N 28 F28-03 Note: All dimensions in inches. 02.18.02 Rev5 All data sheets are subject to change without notice 11 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM Memory 28 PIN RAD-PAK® DUAL IN LINE PACKAGE DIMENSION SYMBOL MIN NOM MAX A -- 0.177 0.225 b 0.014 0.018 0.026 b2 0.045 0.050 0.065 c 0.008 0.010 0.018 D -- 1.400 1.485 E 0.510 0.595 0.620 eA 0.600 BSC eA/2 0.300 BSC e 0.100 BSC L 0.140 0.150 0.160 Q 0.015 0.040 0.060 S1 0.005 0.025 -- S2 0.005 -- -- N 28 D28-03 Note: All dimensions in inches. 02.18.02 Rev5 All data sheets are subject to change without notice 12 ©2001 Maxwell Technologies All rights reserved. 256K EEPROM (32K x 8-Bit) EEPROM 28C256T Important Notice: These data sheets are created using the chip manufacturer’s published specifications. Maxwell Technologies verifies functionality by testing key parameters either by 100% testing, sample testing or characterization. The specifications presented within these data sheets represent the latest and most accurate information available to date. However, these specifications are subject to change without notice and Maxwell Technologies assumes no responsibility for the use of this information. Maxwell Technologies’ products are not authorized for use as critical components in life support devices or systems without express written approval from Maxwell Technologies. Any claim against Maxwell Technologies must be made within 90 days from the date of shipment from Maxwell Technologies. Maxwell Technologies’ liability shall be limited to replacement of defective parts. Memory 02.18.02 Rev5 All data sheets are subject to change without notice 13 ©2001 Maxwell Technologies All rights reserved. 28C256T 256K EEPROM (32K x 8-Bit) EEPROM Product Ordering Options Model Number 28C256T XX X X -XX Option Details Feature 12 = 120 ns 15 = 150 ns Screening Flow Monolithic S = Maxwell Class S B = Maxwell Class B E = Engineering (testing @ +25°C) I = Industrial (testing @ -55°C, +25°C, +125°C) Package D = Dual In-line Package (DIP) F = Flat Pack Radiation Feature RP = RAD-PAK® package RT1 = Guaranteed to 10 krad at die level RT2 = Guaranteed to 25 krad at die level RT4 = Guaranteed to 40 krad at die level Base Product Nomenclature 256K EEPROM (32K x 8-Bit) EEPROM 02.18.02 Rev5 All data sheets are subject to change without notice Memory Access Time 14 ©2001 Maxwell Technologies All rights reserved.