Features
• Ready/Busy Pin
• High Endurance Write Cycles -10,000 Cycles/Byte Minimum
• On-Chip Timer
- Automatic Byte Erase Before Byte Write - 2 ms Byte Write (2864H)
• 5 V± 10% Power Supply
• Power Up/Down Protection Circuitry
• 250 ns max. Access Time
• Military and Extended Temperature Range Available
Description
SEEQ's 2864 is a 5 V only, 8K x 8 NMOS electrically erasable programmable read only memory( EEPROM). It is packaged in a 28 pin package and has a ready/busy pin. This EEPROM is ideal for applications which require non-volatility and in-system data modification. The endurance, the number of times which a byte may be written, is a minimum of 10 thousand cycles.
October 1987
The EEPROM has an internal timer that automatically times out the write time. The on-chip timer, along with the input latches, frees the microcomputer system for tasks during the write time. The standard byte write cycle time is 10 ms. For systems requiring faster byte write, a 2864H is specified at 2 ms. An automatic byte erase is performed before a byte operation is started. Once a byte has been written, the ready/busy pin signals the micropro-cessor that it is available for another write or a read cycle. All inputs are TTL for both the byte write and read mode. Data retention is specified for ten years.
These two timer EEPROMs are ideal for systems with limited board area. For systems where cost is impor-tant, SEEQ has a latch only "528" family at 16K and 64K bit densities. All "528" family inputs, except for write enable, are latched by the falling edge of the write enable signal.
Pin Configuration
DUAL-IN-LINE PLASTIC LEADED CHIP CARRIER
TOP VIEW TOP VIEW
Ao-4 ADDRESSES - COLUMN (LOWER ORDER BITS) AS-12 ADDRESSES - ROW
~ CHIP ENABLE
OE OUTPUT ENABLE
WE WRITE ENABLE
I/O DATA INPUT (WRITE OR ERASE), DATA OUTPUT (READ)
ROY/BUSY DEVICE READY/BUSY
N/C NO CONNECT
seeQ
T e c h n o l o g y , l n c o r p o , . t e d - - - -...MD400002/A 1-37
Device Operation whichever one occurred last. Data is latched on the rising edge of CE or WE, whichever one occurred first. The byte is automatically erased before data is written. While the write operation is in progress, the ROY/BUSY output is at a TTL low. An internal timer times out the required byte write time and at the end of this time, the device signals the ROY/BUSY pin to a TTL high. The ROY/BUSY pin is an open drain output and a typical 3K
n
pull-up resistor to V cc is required. The pull-up resistor value is dependent on the number of OR-tied ROY/BUSY pins. If ROY/BUSY is not used it can be left unconnected.Mode Selection
(Table 1)ROY/ erased simultaneously. This feature is optional and the timing specifications are available from SEEQ.
Power Up/Down Considerations
Writing will also be prevented if CE or OE are in TTL logical states other than that specified for a byte write in the Mode Selection table.
Abso/ute Maximum Stress Ratlngs*
Temperature
Storage ... -650 C to + 15(J" C Under Bias ... -1(J" C to +8(J" C AI/Inputs or Outputs with
Respect to Ground . ... , +6 V to -0.3 V
'COMMENT: Stresses above those listed under "Absolute Maxi-mum 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 above those indicated in the opera-tional sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
2864 H-250/H-300 2864-350
2864-250/-300
I
Vce Supply Voltage 5 V± 10% 5 V± 10%L
Temperature Range: (Ambient) O°C to 70°C O°C to 70°CEndurance and Data Retention
Symbol Parameter Value Units Condition
N Minimum Endurance 10,000 Cycles/Byte MIL-STD 883 Test
Method 1033
TOR Data Retention >10 Years MIL-STD 883 Test
Method 1008 NOTE: 1 - Characterized. Not tested.
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Technology, Incorporated _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ --JMD400002/A 1-38
286412864H
DC Opetatlng Chatacterlstlcs (Over the operating Vee and temperature range) Limits
Symbol Parameter Min. Max. Units Test Condition
Icc Active Vee Current CE = OE = VIL; All I/O Open;
(Includes Write Operation) 110 mA Other Inputs = Vee Max.
ISB Standby Vee Current CE = VIH, OE = VIL; All I/O Open;
40 mA Other Inputs = Vee Max.
III Input Leakage Current 10 ,.,.A VIN = Vee Max.
ILO Output Leakage Current 10 ,.,.A VOUT = Vee Max.
VIL Input Low Voltage -0.1 0.8 V
VIH Input High Voltage 2.0 Vee + 1 V
VOL Output Low Voltage 0.4 V IOL = 2.1 rnA
VOH Output High Voltage 2.4 V IOH = -400 p.A
AC Chatacteristlcs Read Operation (Over the operating Vee and temperature range) Limits
2864H-250 2864H-300
2864-250 2864-300 2864-350
Symbol Parameter Min. Max. Min. Max. Min. Max. Units Test Conditions
tRe Read Cycle Time 250 300 350 ns CE= OE=VIL
teE Chip Enable Access Time 250 300 350 ns OE = VIL
tAA Address Access Time 250 300 350 ns CE = OE = VIL
tOE Output Enable Access Time 90 100 100 ns CE = VIL
tOF Output Enable High to Output Not 0 60 0 60 0 80 ns CE = VIL being Driven
tOH Output Hold from Address Change, Chip 0 0 0 ns CE orOE= VIL
Enable, or Output Enable whichever occurs first
Read Cycle Timing tRC - - - t
---_ Ir--- ---- ---_I
,._---ADDRESSES ADDRESSES VALID
---'
~---- - ----'"'I
"'---OUTPUT---~---_+t+{
NOTES: IAA
tOH VALID OUTPUT
1. OE MAY BE DELAYED T~AA -tOE AFTER THE FALLING EDGE OF CEWITHOUT IMPACT ON lAA.
2. tOF IS SPECIFIED FROM OE ORCE, WHICHEVER OCCURS FIRST.
SeeQ
Technology, Incorporated - - - 'M 0400002/ A 1-39
Capacitance TA [1] = 25°C; f = MHz
Symbol Parameter Max. Conditions CIN Input Capacitance 6 pF VIN =0 V COUT Data (liD) Capacitance 10 pF Vvo=OV
E. S. D. Characteristics[4/
Symbol Parameter Value Test Conditions VZAP E.S.D.
>2000 V MIL-STD 883 Tolerance Test Method 3015
AC Characteristics
Write Operation (Over operating temperature and Vcc range) 2864H-250 Input Rise and Fali Times: <20 ns Input Pulse Levels: 0.45 V to 2.4 V Timing Measurement Reference Level:
Inputs 1 V and 2 V
1. This parameter measured only for the initial qualification and after process or design changes which may affect capacitance.
2. WE is noise protected. Less than a 20 ns write pulse will not activate a write cycle.
3. Data must be valid within 1 p.S maximum after the initiation of a write cycle.
4. Characterized. Not tested.
Units
Write Cycle Timing
Ao-A'2
CE
WE
ROY/BUSY
Ordering Information
TEMPERATURE RANGE D=CERAMIC DIP Q = O°C to + 70°C P= PLASTIC DIP
N=PLASTIC LEADED CHIP CARRIER U=UNENCAPSULATED DIE
286412864H
WRITE CYCLE ---:..---...1--READ CYCLE
--I
DO DO 2864 2864
- 250 H - 250
TIT
DEVICE TYPE 8Kx8 EEPROM
T
EEPROM WRITE TIME ACCESS TIME (BLANK)-STANDARD
WRITE TIME H-FASTWRITETIME
25O=25Onl 3OO=300nl 350=350 nl
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MD400002/A
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