Features • Fast Read Access Time – 70 ns • Automatic Page Write Operation • • • • • • • • • – Internal Address and Data Latches for 64 Bytes – Internal Control Timer Fast Write Cycle Times – Page Write Cycle Time: 3 ms or 10 ms Maximum – 1 to 64-byte Page Write Operation Low Power Dissipation – 80 mA Active Current – 3 mA Standby Current Hardware and Software Data Protection DATA Polling for End of Write Detection High Reliability CMOS Technology – Endurance: 104 or 105 Cycles – Data Retention: 10 Years Si
access times to 70 ns with power dissipation of just 440 mW. When the AT28HC256 is deselected, the standby current is less than 5 mA. The AT28HC256 is accessed like a Static RAM for the read or write cycle without the need for external components. The device contains a 64-byte page register to allow writing of up to 64 bytes simultaneously. During a write cycle, the address and 1 to 64 bytes of data are internally latched, freeing the addresses and data bus for other operations.
AT28HC256 Device Operation READ: The AT28HC256 is accessed like a Static RAM. When CE and OE are low and WE is high, the data stored at the memory location determined by the address pins is asserted on the outputs. The outputs are put in the high impedance state when either CE or OE is high. This dualline control gives designers flexibility in preventing bus contention in their system. BYTE WRITE: A low pulse on the WE or CE input with CE or WE low (respectively) and OE high initiates a write cycle.
DC and AC Operating Range Com. Operating Temperature (Case) Ind. AT28HC256-70 AT28HC256-90 AT28HC256-12 0°C - 70°C 0°C - 70°C 0°C - 70°C -40°C - 85°C -40°C - 85°C -40°C - 85°C -55°C - 125°C -55°C - 125°C 5V ± 10% 5V ± 10% Mil.
AT28HC256 AC Read Characteristics AT28HC256-70 Symbol tACC Parameter Min Max AT28C256-90 Min Max AT28HC256-12 Min Max Units Address to Output Delay 70 90 120 ns (1) CE to Output Delay 70 90 120 ns (2) OE to Output Delay 0 35 0 40 0 50 ns tDF(3)(4) CE or OE to Output Float 0 35 0 40 0 50 ns tOH Output Hold from OE, CE or Address, whichever occurred first 0 tCE tOE 0 0 ns AC Read Waveforms(1)(2)(3)(4) Notes: 1.
AC Write Characteristics Symbol Parameter tAS, tOES Address, OE Setup Time 0 ns tAH Address Hold Time 50 ns tCS Chip Select Setup Time 0 ns tCH Chip Select Hold Time 0 ns tWP Write Pulse Width (WE or CE) 100 ns tDS Data Setup Time 50 ns tDH, tOEH Data, OE Hold Time 0 ns tDV Note: Time to Data Valid 1. NR = No Restriction.
AT28HC256 Page Mode Write Characteristics Symbol Parameter Min Typ Max Units tWC Write Cycle Time (option available) AT28HC256 5 10 ms AT28HC256F 2 3 ms tAS Address Setup Time 0 ns tAH Address Hold Time 50 ns tDS Data Setup Time 50 ns tDH Data Hold Time 0 ns tWP Write Pulse Width 100 ns tBLC Byte Load Cycle Time tWPH Write Pulse Width High 150 50 µs ns Page Mode Write Waveforms(1)(2) Notes: 1.
Software Data Protection Enable Algorithm(1) Software Data Protection Disable Algorithm(1) LOAD DATA AA TO ADDRESS 5555 LOAD DATA AA TO ADDRESS 5555 LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA 55 TO ADDRESS 2AAA LOAD DATA A0 TO ADDRESS 5555 LOAD DATA 80 TO ADDRESS 5555 WRITES ENABLED(2) LOAD DATA XX TO ANY ADDRESS(4) LOAD DATA AA TO ADDRESS 5555 LOAD LAST BYTE TO LAST ADDRESS LOAD DATA 55 TO ADDRESS 2AAA ENTER DATA PROTECT STATE Notes for software program code: 1.
AT28HC256 Data Polling Characteristics(1) Symbol Parameter tDH Data Hold Time tOEH OE Hold Time Min Max OE to Output Delay tWR Write Recovery Time Units 0 ns 0 ns (2) tOE Notes: Typ ns 0 ns 1. These parameters are characterized and not 100% tested. 2. See “AC Read Characteristics” on page 5.
AT28HC256
AT28HC256 Ordering Information(1) ICC (mA) tACC (ns) Active Standby Ordering Code Package 70 80 60 AT28HC256(E,F)-70JC AT28HC256(E,F)-70PC 32J 28P6 Commercial (0°C to 70°C) 0.3 AT28HC256(E,F)-70JI AT28HC256(E,F)-70PI 32J 28P6 Industrial (-40°C to 85°C) 0.3 AT28HC256(E,F)-90JC AT28HC256(E,F)-90PC 32J 28P6 Commercial (0°C to 70°C) AT28HC256(E,F)-90JI AT28HC256(E,F)-90PI 32J 28P6 Industrial (-40°C to 85°C) 90 120 80 Operation Range 80 0.
Ordering Information(1) (Continued) ICC (mA) tACC (ns) Active Standby 90 80 120 Note: Ordering Code Package 0.3 5962-88634 03 UX 5962-88634 03 XX 5962-88634 03 YX 5962-88634 03 ZX 28U 28D6 32L 28F Military/883C Class B, Fully Compliant (-55°C to 125°C) 80 0.3 5962-88634 04 UX 5962-88634 04 XX 5962-88634 04 YX 5962-88634 04 ZX 28U 28D6 32L 28F Military/883C Class B, Fully Compliant (-55°C to 125°C) 80 0.
AT28HC256 Ordering Information Note Previous data sheets included the low power suffixes L, LE and LF on the At28HC256 for 120 ns and 90 ns speeds. The low power parameters are now standard; therefore, the L, LE and LF suffixes are no longer required.
Packaging Information 28D6, 28-lead, 0.600" Wide, Non-windowed, Ceramic Dual Inline Package (Cerdip) Dimensions in Inches and (Millimeters) 28F, 28-lead, Non-windowed, Ceramic Bottombrazed Flat Package (Flatpack) Dimensions in Inches and (Millimeters) MIL-STD-1835 D-10 CONFIG A MIL-STD-1835 F-12 CONFIG B 1.49(37.9) 1.44(36.6) PIN 1 .370(9.40) .250(6.35) PIN #1 ID .019(.483) .015(.381) .610(15.5) .510(13.0) .098(2.49) MAX 1.300(33.02) REF .050(1.27) BSC .728(18.5) .712(18.1) .045(1.14) MAX .
AT28HC256 Packaging Information 28P6, 28-lead, 0.600" Wide, Plastic Dual Inline Package (PDIP) Dimensions in Inches and (Millimeters) 28S, 28-lead, 0.300" Wide, Plastic Gull Wing Small Outline (SOIC) Dimensions in Inches and (Millimeters) JEDEC STANDARD MS-011 AB 1.47(37.3) 1.44(36.6) PIN 1 .566(14.4) .530(13.5) .090(2.29) MAX 1.300(33.02) REF .220(5.59) MAX .005(.127) MIN SEATING PLANE .065(1.65) .015(.381) .022(.559) .014(.356) .161(4.09) .125(3.18) .110(2.79) .090(2.29) .012(.305) .008(.
Atmel Headquarters Atmel Operations Corporate Headquarters Atmel Colorado Springs 2325 Orchard Parkway San Jose, CA 95131 TEL (408) 441-0311 FAX (408) 487-2600 Europe 1150 E. Cheyenne Mtn. Blvd. Colorado Springs, CO 80906 TEL (719) 576-3300 FAX (719) 540-1759 Atmel Rousset Atmel U.K., Ltd.
