AT28BV16 Features • • • • • • • • • 2.7 to 3.6V Supply Full Read and Write Operation Low Power Dissipation 8 mA Active Current 50 µA CMOS Standby Current Read Access Time - 250 ns Byte Write - 3 ms Direct Microprocessor Control DATA Polling READ/BUSY Open Drain Output on TSOP High Reliability CMOS Technology Endurance: 100,000 Cycles Data Retention: 10 Years Low Voltage CMOS Compatible Inputs and Outputs JEDEC Approved Byte Wide Pinout Commercial and Industrial Temperature Ranges 16K (2K x 8) Battery-Voltage CMOS E2PROM Description The AT28BV16 is a low-power, high-performance Electrically Erasable and Programmable Read Only Memory with easy to use features. The AT28BV16 is a 16K memory organized as 2,048 words by 8 bits. The device is manufactured with Atmel’s reliable nonvolatile CMOS technology. The AT28BV16 is accessed like a static RAM for the read or write cycles without the need of external components. During a byte write, the address and data are latched (continued) Pin Configurations Pin Name Function A0 - A10 Addresses CE Chip Enable OE Output Enable WE Write Enable I/O0 - I/O7 Data Inputs/Outputs NC No Connect DC Don’t Connect PDIP, SOIC Top View TSOP Top View AT28BV16 PLCC Top View 0308A 2-119 Description (Continued) internally, freeing the microprocessor address and data bus for other operations. Following the initiation of a write cycle, the device will go to a busy state and automatically clear and write the latched data using an internal control timer. The end of a write cycle can be determined by DATA polling of I/O7. Once the end of a write cycle has been detected, a new access for a read or a write can begin. The CMOS technology offers fast access times of 250 ns at low power dissipation. When the chip is deselected the standby current is less than 50 µA. Atmel’s 28BV16 has additional features to ensure high quality and manufacturability. The device utilizes error correction internally for extended endurance and for improved data retention characteristics. An extra 32-bytes of E2PROM are available for device identification or tracking. Block Diagram Absolute Maximum Ratings* Temperature Under Bias................. -55°C to +125°C Storage Temperature...................... -65°C to +150°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 2-120 AT28BV16 *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. AT28BV16 Device Operation READ: The AT28BV16 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 AT28BV16 is similar to writing into a Static RAM. A low pulse on the WE or CE input with OE high and CE or WE low (respectively) initiates a byte write. The address location is latched on the last falling edge of WE (or CE); the new data is latched on the first rising edge. Internally, the device performs a selfclear before write. Once a byte write has been started, it will automatically time itself to completion. Once a programming operation has been initiated and for the duration of tWC, a read operation will effectively be a polling operation. READY/BUSY (TSOP only): READY/BUSY is an open drain output; it is pulled low during the internal write cycle and released at the completion of the write cycle. WRITE PROTECTION: Inadvertent writes to the device are protected against in the following ways. (a) Vcc sense— if Vcc is below 2.0V (typical) the write function is inhibited. (b) Vcc power on delay— once Vcc has reached 2.0V the device will automatically time out 5 ms (typical) before allowing a byte write. (c) Write Inhibit— holding any one of OE low, CE high or WE high inhibits byte write cycles. DEVICE IDENTIFICATION: A n ex t r a 32- bytes of E2PROM memory are available to the user for device identification. By raising A9 to 12 ± 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. DATA POLLING: The AT28BV16 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/O7 (the other outputs are indeterminate). When the write cycle is finished, true data appears on all outputs. 2-121 DC and AC Operating Range Com. Operating Temperature (Case) Ind. VCC Power Supply AT28BV16-25 AT28BV16-30 0°C - 70°C 0°C - 70°C -40°C - 85°C -40°C - 85°C 2.7V to 3.6V 2.7V to 3.6V Operating Modes Mode CE OE WE I/O Read VIL VIL VIH DOUT VIL VIH VIL DIN VIH (1) Write (2) Standby/Write Inhibit X X Write Inhibit X X VIH Write Inhibit X VIL X Output Disable X VIH X High Z High Z Notes: 1. X can be VIL or VIH. 2. Refer to AC Programming Waveforms. DC Characteristics Symbol Parameter Condition Min Max Units ILI Input Load Current VIN = 0V to VCC + 1.0V 5 µA ILO Output Leakage Current VI/O = 0V to VCC 5 µA ISB VCC Standby Current CMOS CE = VCC - 0.3V to VCC + 1.0V 50 µA ICC VCC Active Current AC f = 5 MHz; IOUT = 0 mA; CE = VIL 8 mA VIL Input Low Voltage 0.6 V VIH Input High Voltage VOL Output Low Voltage VOH Output High Voltage 2-122 AT28BV16 2.0 V IOL = 1 mA 0.3 V IOL = 2 mA for RDY/BUSY 0.3 V IOH = -100 µA 2.0 V AT28BV16 AC Read Characteristics AT28BV16-25 Symbol Parameter tACC Min Max AT28BV16-30 Min Max Units Address to Output Delay 250 300 ns tCE (1) CE to Output Delay 250 300 ns tOE (2) OE to Output Delay 100 100 ns tDF (3, 4) CE or OE High to Output Float 0 55 ns Output Hold from OE, CE or Address, whichever occurred first 0 tOH 55 0 0 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 < 20 ns Pin Capacitance (f = 1 MHz, T = 25°C) (1) Typ Max Units CIN 4 6 pF VIN = 0V COUT 8 12 pF VOUT = 0V Note: Conditions 1. This parameter is characterized and is not 100% tested. 2-123 AC Write Characteristics Symbol Parameter Min tAS, tOES Address, OE Set-up Time 10 ns tAH Address Hold Time 100 ns tWP Write Pulse Width (WE or CE) 150 tDS Data Set-up Time 100 ns tDH, tOEH Data, OE Hold Time 10 ns tCS, tCH CE to WE and WE to CE Set-up and Hold Time 0 ns tWC Write Cycle Time 3.0 ms tDB Time to Device Busy 50 ns AC Write Waveforms WE Controlled CE Controlled 2-124 AT28BV16 Max 1000 Units ns AT28BV16 Data Polling Characteristics (1) Symbol Parameter Min Typ Max Units tDH Data Hold Time 10 ns tOEH OE Hold Time 10 ns tOE OE to Output Delay (2) tWR Write Recovery Time ns 0 ns Notes: 1. These parameters are characterized and not 100% tested. 2. See AC Characteristics. Data Polling Waveforms 2-125 Ordering Information (1) tACC ICC (mA) Ordering Code Package 0.05 AT28BV16-25TC AT28BV16-25JC AT28BV16-25PC AT28BV16-25SC 28T 32J 24P6 24S Commercial (0°C to 70°C) 8 0.05 AT28BV16-25TI AT28BV16-25JI AT28BV16-25PI AT28BV16-25SI 28T 32J 24P6 24S Industrial (-40°C to 85°C) 8 0.05 AT28BV16-30TC AT28BV16-30JC AT28BV16-30PC AT28BV16-30SC 28T 32J 24P6 24S Commercial (0°C to 70°C) 8 0.05 AT28BV16-30TI AT28BV16-30JI AT28BV16-30PI AT28BV16-30SI 28T 32J 24P6 24S Industrial (-40°C to 85°C) (ns) Active Standby 250 8 300 Note: 1. See Valid Part Number table below. Valid Part Numbers The following table lists standard Atmel products that can be ordered. Device Numbers Speed Package and Temperature Combinations AT28BV16 25 JC, JI, PC, PI, SC, SI, TC, TI AT28BV16 30 JC, JI, PC, PI, SC, SI, TC, TI Package Type 28T 28 Lead, Plastic Thin Small Outline Package (TSOP) 32J 32 Lead, Plastic J-Leaded Chip Carrier (PLCC) 24P6 24 Lead, 0.600" Wide, Plastic Dual Inline Package (PDIP) 24S 24 Lead, 0.300" Wide, Plastic Gull Wing Small Outline (SOIC) 2-126 AT28BV16 Operation Range