Rainbow Electronics AT28C256 - Manual

1
Features
• Fast Read Access Time – 150 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
– 50 mA Active Current
– 200
µA CMOS Standby Current
• Hardware and Software Data Protection
• DATA Polling for End of Write Detection
• High Reliability CMOS Technology
– Endurance: 10 4 or 10 5 Cycles
– Data Retention: 10 Years
• Single 5V ± 10% Supply
• CMOS and TTL Compatible Inputs and Outputs
• JEDEC Approved Byte-wide Pinout
• Full Military, Commercial, and Industrial Temperature Ranges
Description
The AT28C256 is a high-performance electrically erasable and programmable read
only memory. Its 256K of memory is organized as 32,768 words by 8 bits. Manufac-
tured with Atmel’s advanced nonvolatile CMOS technology, the device offers access
times to 150 ns with power dissipation of just 440 mW. When the device is deselected,
the CMOS standby current is less than 200
µA.
256K (32K x 8)
Paged Parallel
EEPROM
AT28C256
Rev. 0006H–12/99
Pin Configurations
Pin Name Function
A0 - A14 Addresses
CE Chip Enable
OE Output Enable
WE Write Enable
I/O0 - I/O7 Data Inputs/Outputs
NC No Connect
DC Don’t Connect
CERDIP, PDIP, FLATPACK,
SOIC — Top View
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
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O0
I/O1
I/O2
GND
VCC
WE
A13
A8
A9
A11
OE
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
TSOP
Top View
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
OE
A11
A9
A8
A13
WE
VCC
A14
A12
A7
A6
A5
A4
A3
A10
CE
I/O7
I/O6
I/O5
I/O4
I/O3
GND
I/O2
I/O1
I/O0
A0
A1
A2
LCC, PLCC
Top View
Note: PLCC package pins 1 and
17 are DON’T CONNECT.
5
6
7
8
9
10
11
12
13
29
28
27
26
25
24
23
22
21
A6
A5
A4
A3
A2
A1
A0
NC
I/O0
A8
A9
A11
NC
OE
A10
CE
I/O7
I/O6
4 3 2 1
32 31 30
14 15 16 17 18 19 20
I/O1 I/O2 GND
DC
I/O3 I/O4 I/O5
A7 A12 A14 DC VCC WE A13
(continued)
PGA
Top View