AT27C400
Features
• Fast Read Access Time - 70 ns
• Word-wide or Byte-wide Configurable
• 4 Megabit Flash and Mask ROM Compatible
• Low Power CMOS Operation
– 100 µA Maximum Standby
– 50 mA Maximum Active at 5 MHz
• Wide Selection of JEDEC Standard Packages
– 40-Lead 600 mil PDIP
– 40-Lead SOIC (SOP)
– 48-Lead TSOP (12 mm x 20 mm)
• 5V ± 10% Power Supply
4-Megabit
(256K x 16 or
512K x 8) OTP
EPROM
• High Reliability CMOS Technology
– 2,000V ESD Protection
– 200 mA Latchup Immunity
• Rapid™Programming Algorithm - 50 µs/word (typical)
• CMOS and TTL Compatible Inputs and Outputs
• Integrated Product Identification Code
• Commercial and Industrial Temperature Ranges
AT27C400
Description
The AT27C400 is a low-power, high-performance 4,194,304-bit one-time programma-
ble read only memory (OTP EPROM) organized as either 256K by 16 or 512K by 8
bits. It requires a single 5V power supply in normal read mode operation. Any word
can be accessed in less than 70 ns, eliminating the need for speed-reducing WAIT
states. The by-16 organization makes this part ideal for high-performance 16- and 32-
bit microprocessor systems.
Preliminary
PDIP Top View
SOIC (SOP)
Pin Configurations
A17
A7
A6
A5
A4
A3
A2
A1
A0
1
2
3
4
5
6
7
8
9
40 A8
A17
A7
A6
A5
A4
A3
A2
A1
A0
1
2
3
4
5
6
7
8
9
40 A8
39 A9
39 A9
Pin Name
A0 - A17
O0 - O15
O15/A-1
Function
38 A10
37 A11
36 A12
35 A13
34 A14
33 A15
32 A16
31 BYTE/VPP
30 GND
29 015/A-1
28 O7
38 A10
37 A11
36 A12
35 A13
34 A14
33 A15
32 A16
31 BYTE/VPP
30 GND
29 015/A-1
28 O7
Addresses
Outputs
CE 10
GND 11
OE 12
O0 13
O8 14
O1 15
O9 16
O2 17
O10 18
O3 19
O11 20
CE 10
GND 11
OE 12
O0 13
O8 14
O1 15
O9 16
O2 17
O10 18
O3 19
O11 20
Output/Address
Byte Mode/
Program Supply
27 O14
26 O6
27 O14
26 O6
BYTE/VPP
25 O13
24 O5
25 O13
24 O5
CE
OE
NC
Chip Enable
Output Enable
No Connect
23 O12
22 O4
23 O12
22 O4
21 VCC
21 VCC
TSOP
Type 1
Note: Both GND pins must be
connected.
A15
A14
A13
A12
A11
A10
A9
1
48
47
46
45
44
43
42
41
40
39
38
37
36
35
34
33
32
31
30
29
28
27
26
25
A16
2
BYTE/VPP
GND
015/A-1
I/O7
O14
O6
3
4
5
6
7
A8
8
O13
O5
NC
NC
NC
NC
NC
NC
NC
NC
A17
A7
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
O12
O4
VCC
O11
O3
O10
O2
O9
O1
A6
O8
A5
O0
A4
OE
A3
GND
CE
0844A-A–7/97
A2
A1
A0
1