28C256 256K 150ns Parallel EEPROM (RoHS Compliant) – Datasheet

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. When the device is deselected, the CMOS standby current is less than 200 µA. The AT28C256 is accessed like a Static RAM for the read or write cycle without the need for external components.

The device contains a 64-byte page register to allow writing of up to 64 bytes simultaneously. During a write cycle, the addresses and 1 to 64 bytes of data are internally latched, freeing the address and data bus for other operations. Following the initiation of a write cycle, the device will automatically write the latched data using an internal control timer.

28C256 Pinout

28C256 Pin Configuration

Pin No	Pin Name	Description
1	A14	Address Pin 14
2	A12	Address Pin 12
3	A7	Address Pin 7
4	A6	Address Pin 6
5	A5	Address Pin 5
6	A4	Address Pin 4
7	A3	Address Pin 3
8	A2	Address Pin 2
9	A1	Address Pin 1
10	A0	Address Pin 0
11	I/O 0	Data Inputs/Outputs 0
12	I/O 1	Data Inputs/Outputs 1
13	I/O 2	Data Inputs/Outputs 2
14	GND	Ground Pin
15	I/O 3	Data Inputs/Outputs 3
16	I/O 4	Data Inputs/Outputs 4
17	I/O 5	Data Inputs/Outputs 5
18	I/O 6	Data Inputs/Outputs 6
19	I/O 7	Data Inputs/Outputs 7
20	CE’	Chip Enable Pin
21	A10	Address Pin 10
22	OE’	Output Enable
23	A11	Address Pin 11
24	A9	Address Pin 9
25	A8	Address Pin 8
26	A13	Address Pin 13
27	WE’	Write Enable Pin
28	VCC	Supply Voltage Pin

28C256 Key Feature

• 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
• Green (Pb/Halide-free) Packaging Option

You can download this datasheet for 28C256 256K 150ns Parallel EEPROM (RoHS Compliant) – Datasheet from the link given below: