27C256
256K (32K x 8) CMOS EPROM
FEATURES
PACKAGE TYPES
TSOP
• High speed performance
OE
A11
A9
1
2
3
4
5
6
7
28
27
26
25
24
23
22
A10
CE
D7
D6
D5
D4
D3
- 90 ns access time available
• CMOS Technology for low power consumption
- 20 mA Active current
A8
A13
A14
VCC
- 100 µA 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
VPP
A12
8
9
21
20
19
18
17
16
15
VSS
D2
D1
D0
A0
A1
A2
A7 10
A6 11
A5 12
A4 13
A3 14
PLCC
- 32-pin PLCC Package
5
29
28
27
26
25
24
23
22
21
A6
A5
A4
A3
A2
A1
A0
NC
O0
A8
A9
6
- 28-pin SOIC package
7
A11
NC
OE
A10
CE
O7
O6
- 28-pin Thin Small Outline Package (TSOP)
- 28-pin Very Small Outline Package (VSOP)
- Tape and reel
8
9
10
11
12
13
• Data Retention > 200 years
• Available for the following temperature ranges:
- Commercial:
- Industrial:
0˚C to +70˚C
DIP/SOIC
-40˚C to +85˚C
-40˚C to +125˚C
- Automotive:
VPP
1
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VCC
A14
A13
A8
A12
A7
A6
A5
A4
A3
A2
A1
A0
O0
O1
O2
VSS
2
DESCRIPTION
3
4
5
A9
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.
6
A11
OE
A10
CE
O7
7
8
9
10
11
12
13
14
O6
O5
O4
O3
VSOP
OE
A11
A9
A8
A13
A14
22
23
24
25
26
27
A10
21
20
19
18
17
16
15
14
13
12
11
10
9
CE
O7
O6
O5
O4
O3
VSS
O2
O1
O0
A0
A1
A2
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.
28
1
VCC
VPP
2
3
4
5
6
7
A12
A7
A6
A5
A4
A3
8
1996 Microchip Technology Inc.
DS11001L-page 1
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