Features • Ideal Rewritable Attribute Memory • Simple Write Operation • • • • – Self-Timed Byte Writes – On-chip Address and Data Latch for SRAM-like Write Operation – Fast Write Cycle Time - 1 ms – 5-Volt-Only Nonvolatile Writes End of Write Detection – RDY/BUSY Output – DATA Polling High Reliability – Endurance: 100,000 Write Cycles – Data Retention: 10 Years Minimum Single 5-Volt Supply for Read and Write Very Low Power – 30 mA Active Current – 100 µA Standby Current Description The AT28C16-T is the ideal nonvolatile attribute memory: it is a low power, 5-volt-only byte writable nonvolatile memory (EEPROM). Standby current is typically less than 100 µA. The AT28C16-T is written like a Static RAM, eliminating complex programming algorithms. The fast write cycle times of 1 ms, allow quick card reconfiguration in-system. Data retention is specified as 10 years minimum, precluding the necessity for batteries. Three access times have been specified to allow for varying layers of buffering between the memory and the PCMCIA interface. The AT28C16-T is accessed like a Static RAM for read and write operations. During a byte write, the address and data are latched internally. Following the initiation of a write cycle, the device will go to a busy state and automatically write the latched data using an internal control timer. The device provides two methods for detecting the end of a write cycle; the RDY/BUSY output and DATA POLLING of I/O7. 16K (2K x 8) PCMCIA Nonvolatile Attribute Memory AT28C16-T Pin Configurations Pin Name Function A0 - A10 Addresses CE Chip Enable OE Output Enable WE Write Enable I/O0 - I/O7 Data Inputs/Outputs RDY/BUSY Ready/Busy Output NC No Connect TSOP Top View OE NC A9 A8 NC WE VCC RDY/BUSY NC A7 A6 A5 A4 A3 1 2 3 4 5 6 7 8 9 10 11 12 13 14 28 27 26 25 24 23 22 21 20 19 18 17 16 15 A10 CE I/O7 I/O6 I/O5 I/O4 I/O3 GND I/O2 I/O1 I/O0 A0 A1 A2 Rev. 0258C–10/98 1 Block Diagram Absolute Maximum Ratings* Temperature Under Bias ................................ -55°C to +125°C Storage Temperature ..................................... -65°C to +125°C All Input Voltages (including NC Pins) with Respect to Ground ...................................-0.6V to +6.25V All Output Voltages with Respect to Ground .............................-0.6V to VCC + 0.6V Voltage on OE and A9 with Respect to Ground ...................................-0.6V to +13.5V 2 AT28C16-T *NOTICE: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or any other conditions beyond 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 AT28C16-T Device Operation READ: The AT28C16-T 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 a high impedance state whenever CE or OE is high. This dual-line control gives designers increased flexibility in preventing bus contention. BYTE WRITE: Writing data into the AT28C16-T is similar to writing into a Static RAM. A low pulse on WE or CE input with OE high and CE or WE low (respectively) initiates a byte write. The address is latched on the falling edge of WE or CE (whichever occurs last) and the data is latched on the rising edge of WE or CE (whichever occurs first). Once a byte write is started it will automatically time itself to completion. For the AT28C16-T the write cycle time is 1 ms maximum. Once a programming operation has been initiated and for the duration of tWC, a read operation will effectively be a polling operation. READY/BUSY: Pin 1 is an open drain READY/BUSY output that indicates the current status of the self-timed internal write cycle. READY/BUSY is actively pulled low during the write cycle and is released at the completion of the write. The open drain output allows OR-tying of several devices to a common interrupt input. DATA POLLING: The AT28C16-T also provides DATA polling to signal the completion of a write cycle. During a write cycle, an attempted read of the data being written results in the complement of that data for I/O 7 (the other outputs are indeterminate). When the write cycle is finished, true data appears on all outputs. WRITE PROTECTION: Inadvertent writes to the device are protected against in the following ways: (a) VCC sense—if VCC is below 3.8V (typical) the write function is inhibited; (b) V CC power on delay—once V CC has reached 3.8V the device will automatically time out 5 ms (typical) before allowing a byte write; and (c) write inhibit—holding any one of OE low, CE high or WE high inhibits byte write cycles. CHIP CLEAR: The contents of the entire memory of the AT28C16-T may be set to the high state by the Chip Clear operation. By setting CE low and OE to 12V, the chip is cleared when a 10 ms low pulse is applied to WE. DEVICE IDENTIFICATION: An extra 32 bytes of EEPROM memory are available to the user for device identification. By raising A9 to 12V (± 0.5V) and using address locations 7E0H to 7FFH the additional bytes may be written to or read from in the same manner as the regular memory array. 3 DC and AC Operating Range AT28C16-15T Operating Temperature (Case) Com. 0°C - 70°C Ind. -40°C - 85°C 5V ± 10% VCC Power Supply Operating Modes Mode CE OE WE I/O Read VIL VIL VIH DOUT VIL VIH VIL DIN High Z Write (2) Standby/Write Inhibit (1) VIH X X Write Inhibit X X VIH Write Inhibit X VIL X Output Disable X VIH X High Z VIL High Z Chip Erase Notes: VIL VH (3) 1. X can be VIL or VIH. 2. Refer to AC Programming Waveforms. 3. VH = 12.0V ± 0.5V. DC Characteristics Symbol Parameter Condition ILI Input Load Current ILO Max Units VIN = 0V to VCC + 1V 10 µA Output Leakage Current VI/O = 0V to VCC 10 µA ISB1 VCC Standby Current CMOS CE = VCC - 0.3V to VCC + 1.0V 100 µA Com. 2 mA ISB2 VCC Standby Current TTL CE = 2.0V to VCC + 1.0V Ind. 3 mA Com. 30 mA ICC VCC Active Current f = 5 MHz; IOUT = 0 mA Ind. 45 mA VIL Input Low Voltage 0.8 V VIH Input High Voltage VOL Output Low Voltage IOL = 2.1 mA VOH Output High Voltage IOH = -400 µA 4 Min 2.0 AT28C16-T V 0.4 2.4 V V AT28C16-T AC Read Characteristics AT28C16-15T PCMCIA Symbol Atmel Symbol Parameter Min tC (R) tRC Read Cycle Time 150 tA (A) tACC Max Units ns Address Access Time 150 ns tA (CE) tCE (1) CE Access Time 150 ns tA (OE) tOE(2) OE Access Time 0 75 ns tEN (CE) tLz(4) Output Enable Time From CE 0 ns Output Enable Time From OE 0 ns ns (4) tEN (OE) tOLZ tV (A) tOH Output Hold Time 0 tDIS (CE) tDF(3)(4) Output Disable Time From CE 0 50 ns tDIS (OE) tDF(3)(4) Output Disable Time From OE 0 50 ns AC Read Waveforms(1)(2)(3)(4) Notes: 1. CE may be delayed up to tACC - tCE after the address transition without impact on tACC. 2. OE may be delayed up to tCE - tOE after the falling edge of CE without impact on tCE or by tACC - tOE after an address change without impact on tACC. 3. tDF is specified from OE or CE whichever occurs first (CL = 5 pF). 4. This parameter is characterized and is not 100% tested. Input Test Waveforms and Measurement Level Output Test Load tR, tF < 5 ns Pin Capacitance f = 1 MHz, T = 25°C(1) Symbol Typ Max Units Conditions CIN 4 6 pF VIN = 0V COUT 8 12 pF VOUT = 0V Note: 1. This parameter is characterized and is not 100% tested. 5 AC Write Characteristics PCMCIA Symbol Atmel Symbol Parameter Min tSU (A) tAS Address Setup Time 10 ns tSU (OE-WE) tOES Output Disable Time To WE 10 ns tSU (CE-WE) tCS Chip Enable Time To WE 0 ns tW (WE) tWP Write Enable Pulse Width 100 tSU (D-WEH) tDS Data Setup To WE High 50 ns tH (A) tAH Address Hold Time From WE 50 ns tH (D) tDH Data Hold Time From WE High 10 ns tH (OE-WE) tOEH Output Enable Hold Time From WE High 10 ns tH (CE-WE) tCH Chip Enable Hold Time From WE High 0 ns tD (B) tDB Delay From WE High To BUSY Asserted 50 ns tC (W) tWC Write Cycle Time 1 ms AC Write Waveforms 6 AT28C16-T Max 1000 Units ns AT28C16-T Data Polling Waveforms Note: 1. Data Polling AC Timing Characteristics are the same as the AC Read Characteristics. Chip Erase Waveforms tS = tH = 1 µsec (min.) tW = 10 msec (min.) VH = 12.0 ± 0.5V 7 Ordering Information ICC (mA) tACC (ns) Active Standby Ordering Code Package 150 30 0.1 AT28C16-15TC 28T Commercial (0°C to 70°C) 45 0.1 AT28C16-15TI 28T Industrial (-40°C to 85°C) Notes: Operation Range 1. See Valid Part Numbers table below. 2. The 28C16 200 ns and 250 ns speed selections have been removed from valid selections table and are replaced by the faster 150 ns TAA offering. Valid Part Numbers The following table lists standard Atmel products that can be ordered. Device Numbers AT28C16 Speed 15 Package and Temperature Combinations TC, TI Die Products Reference Section: Parallel EEPROM Die Products Package Type 28T 8 28-Lead, Plastic Thin Small Outline Package (TSOP) AT28C16-T AT28C16-T Packaging Information 28T, 28-Lead, Plastic Thin Small Outline Package (TSOP) Dimensions in Millimeters and (Inches)* INDEX MARK AREA 11.9 (0.469) 11.7 (0.461) 13.7 (0.539) 13.1 (0.516) 0.27 (0.011) 0.18 (0.007) 0.55 (0.022) BSC 7.15 (0.281) REF 8.10 (0.319) 7.90 (0.311) 1.25 (0.049) 1.05 (0.041) 0.20 (0.008) 0.10 (0.004) 0 5 REF 0.20 (0.008) 0.15 (0.006) 0.70 (0.028) 0.30 (0.012) *Controlling dimension: millimeters 9 10 AT28C16-T AT28C16-T 11 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. 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The Company assumes no responsibility for any errors which may appear in this document, reserves the right to change devices or specifications detailed herein at any time without notice, and does not make any commitment to update the information contained herein. No licenses to patents or other intellectual proper ty of Atmel are granted by the Company in connection with the sale of Atmel products, expressly or by implication. Atmel’s products are not authorized for use as critical components in life suppor t devices or systems. Marks bearing ® and/or ™ are registered trademarks and trademarks of Atmel Corporation. Terms and product names in this document may be trademarks of others. Printed on recycled paper. 0258C–10/98/xM