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
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
Function
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
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