1996 Microchip Technology Inc. DS11001L-page 1
27C256

FEATURES

• High speed performance
- 90 ns access time available
• CMOS Technology for low power consumption
- 20 mA Active current
- 100

m

A Standby current
• Factory programming available
• Auto-insertion-compatible plastic packages
• Auto ID aids automated programming
• Separate chip enable and output enable controls
• High speed “express” programming algorithm
• Organized 32K x 8: JEDEC standard pinouts
- 28-pin Dual-in-line package
- 32-pin PLCC Package
- 28-pin SOIC package
- 28-pin Thin Small Outline Package (TSOP)
- 28-pin Very Small Outline Package (VSOP)
- Tape and reel
• Data Retention > 200 years
• Available for the following temperature ranges:
- Commercial: 0˚C to +70˚C
- Industrial: -40˚C to +85˚C
- Automotive: -40˚C to +125˚C

DESCRIPTION

The Microchip Technology Inc. 27C256 is a CMOS
256K bit electrically Programmable Read Only Memory
(EPROM). The device is organized as 32K words by 8
bits (32K bytes). Accessing individual bytes from an
address transition or from power-up (chip enable pin
going low) is accomplished in less than 90 ns. This very
high speed device allows the most sophisticated micro-
processors to run at full speed without the need for
WAIT states. CMOS design and processing enables
this part to be used in systems where reduced power
consumption and reliability are requirements.
A complete family of packages is offered to provide the
most flexibility in applications. For surface mount appli-
cations, PLCC, SOIC, VSOP or TSOP packaging is
available. Tape and reel packaging is also available for
PLCC or SOIC packages.

PACKAGE TYPES
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
VPP
A12
A7
A6
A5
A4
A3
A2
A1
A0
O0
O1
O2
VSS


VCC
A14
A13
A8
A9
A11
OE
A10
CE
O7
O6
O5
O4
O3


OE
A11
A9
A8
A13
A14
VCC

VPP
A12
A7
A6
A5
A4
A3
A10
CE
D7
D6
D5
D4
D3

VSS
D2
D1
D0
A0
A1
A2
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
A6
A5
A4
A3
A2
A1
A0
NC
O0
A8
A9
A11
NC
OE
A10
CE
O7
O6
A7 A12 V NU Vcc A14 A13
O1 O2
V NU
O3 O4 O5
PP
SS
5
6
7
8
9
10
11
12
13
29
28
27
26
25
24
23
22
21
14 15 16 17 18 19 20
4 3 2 1
32 31 30
A10
CE
21
20
19
VSS
O2
14
13
12
OE
A11
A9
A8
22
23
24
VPP
A12
A7
1
2
3
4
5
25
26
27
28
6
7
A13
A14
VCC
A6
A5
A4
A3
O7
O6
O5
O4
O3
O1
O0

A0
A1
A2
18
17
16
15
11
10
9
8
TSOP
PLCC
DIP/SOIC
VSOP
27C256
27C256
27C256
27C256

256K (32K x 8) CMOS EPROM

This document was created with FrameMaker404