AT27C040
Features
•
Fast Read Access Time - 70 ns
•
Low Power CMOS Operation
•
100
µA
max. Standby
30 mA max. Active at 5 MHz
JEDEC Standard Packages
32-Lead 600-mil PDIP
32-Lead 450-mil SOIC (SOP)
32-Lead PLCC
32-Lead TSOP
5V
±
10% Supply
High Reliability CMOS Technology
2000V ESD Protection
200 mA Latchup Immunity
Rapid
™
Programming Algorithm - 100
µs/byte
(typical)
CMOS and TTL Compatible Inputs and Outputs
Integrated Product Identification Code
Commercial and Industrial Temperature Ranges
•
•
•
•
•
•
4-Megabit
(512K x 8)
OTP EPROM
AT27C040
Description
The AT27C040 chip is a low-power, high-performance, 4,194,304-bit one-time pro-
grammable read only memory (OTP EPROM) organized as 512K by 8 bits. The
AT27C040 requires only one 5V power supply in normal read mode operation. Any
byte can be accessed in less than 70 ns, eliminating the need for speed reducing
WAIT states on high-performance microprocessor systems.
Atmel's scaled CMOS technology provides low active power consumption, and fast
programming. Power consumption is typically 8 mA in active mode and less than 10
µ
A in standby mode.
(continued)
Pin Configurations
Pin Name
A0 - A18
O0 - O7
CE
OE
Function
Addresses
Outputs
Chip Enable
Output Enable
PDIP, SOIC Top View
PLCC Top View
TSOP Top View
0189E-A–7/97
1
The AT27C040 is available in a choice of industry standard
JEDEC-approved one-time programmable (OTP) plastic
PDIP, PLCC, SOIC (SOP), and TSOP packages. The
device features two-line control (CE, OE) to eliminate bus
contention in high-speed systems.
Atmel's AT27C040 has additional features to ensure high
quality and efficient production use. The Rapid
™
Program-
ming Algorithm reduces the time required to program the
part and guarantees reliable programming. Programming
time is typically only 100
µs/byte.
The Integrated Product
Identification Code electronically identifies the device and
manufacturer. This feature is used by industry standard
programming equipment to select the proper programming
algorithms and voltages.
Switching Considerations
Switching between active and standby conditions via the
Chip Enable pin may produce transient voltage excursions.
Unless accommodated by the system design, these tran-
sients may exceed data sheet limits, resulting in device
non-conformance. At a minimum, a 0.1
µF
high frequency,
low inherent inductance, ceramic capacitor should be uti-
lized for each device. This capacitor should be connected
between the V
CC
and Ground terminals of the device, as
close to the device as possible. Additionally, to stabilize the
supply voltage level on printed circuit boards with large
EPROM arrays, a 4.7
µF
bulk electrolytic capacitor should
be utilized, again connected between the V
CC
and Ground
terminals. This capacitor should be positioned as close as
possible to the point where the power supply is connected
to the array.
2
AT27C040
AT27C040
Block Diagram
Operating Modes
Mode/Pin
Read
Output Disable
Standby
Rapid Program
(2)
PGM Verify
PGM Inhibit
Product Identification
Notes:
(4)
CE
V
IL
X
V
IH
V
IL
X
V
IH
V
IL
OE
V
IL
V
IH
X
V
IH
V
IL
V
IH
V
IL
Ai
Ai
X
X
Ai
Ai
X
A9 = V
H(3)
A0 = V
IH
or V
IL
A1 - A18 = V
IL
V
PP
X
(1)
X
X
V
PP
V
PP
V
PP
X
Outputs
D
OUT
High Z
High Z
D
IN
D
OUT
High Z
Identification Code
1. X can be V
IL
or V
IH
.
2. Refer to Programming Characteristics
3. V
H
= 12.0
±
0.5V.
4. Two identifier bytes may be selected. All Ai inputs are held low (V
IL
), except A9 which is set to V
H
and A0 which is toggled
low (V
IL
) to select the Manufacturer’s Identificaton byte and high (V
IH
) to select the Device Code byte.
Absolute Maximum Ratings*
Temperature Under Bias ......................-55°C to +125°C
Storage Temperature............................-65°C to +150°C
Voltage on Any Pin with
Respect to Ground ..............................-2.0V to +7.0V
(1)
Voltage on A9 with
Respect to Ground ...........................-2.0V to +14.0V
(1)
V
PP
Supply Voltage with
Respect to Ground ............................-2.0V to +14.0V
(1)
*NOTICE:
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. This is a
stress rating only and functional operation of the device at these or any other conditions beyond those indicated in the oper-
ational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods
may affect device reliability.
3
DC and AC Operating Conditions for Read Operation
AT27C040
-70
Operating
Temperature (Case)
V
CC
Power Supply
Com.
Ind.
0°C - 70°C
-40°C - 85°C
5V
±
10%
-90
0°C - 70°C
-40°C - 85°C
5V
±
10%
-12
0°C - 70°C
-40°C - 85°C
5V
±
10%
-15
0°C - 70°C
-40°C - 85°C
5V
±
10%
DC and Operating Characteristics for Read Operation
Symbol
I
LI
I
LO
I
PP1(2)
I
SB
I
CC
V
IL
V
IH
V
OL
V
OH
Notes:
Paramter
Input Load Current
Output Leakage Current
V
PP(1)
Read/Standby Current
V
CC1(1)
Standby Current
V
CC
Active Current
Input Low Voltage
Input High Voltage
Output Low Voltage
Output High Voltage
Condition
V
IN
= 0V to V
CC
V
OUT
= 0V to V
CC
V
PP
= V
CC
I
SB1
(CMOS), CE = V
CC
±
0.3V
I
SB2
(TTL), CE = 2.0 to V
CC
+ 0.5V
f = 5 MHz, I
OUT
= 0 mA,
CE = V
IL
Min
Max
±1
±5
10
100
1
30
Units
µA
µA
µA
µA
mA
mA
V
V
V
V
-0.6
2.0
I
OL
= 2.1 mA
I
OH
= -400
µA
2.4
0.8
V
CC
+
0.5
0.4
1. V
CC
must be applied simultaneously or before V
PP
, and removed simultaneously or after V
PP
.
2. V
PP
may be connected directly to V
CC
, except during programming. The supply current would then be the sum of I
CC
and
I
PP
.
AC Characteristics for Read Operation
AT27C040
-70
Symbol
t
ACC(3)
t
CE(2)
t
OE(2)(3)
t
DF
(4)(5)
-90
Min
Max
90
90
35
20
Min
-12
Max
120
120
35
30
Min
-15
Max
150
150
40
30
Units
ns
ns
ns
ns
Parameter
Address to Output Delay
CE to Output Delay
OE to Output Delay
OE or CE High to Output
Float, whichever occurred
first
Output Hold from Address,
CE or OE, whichever
occurred first
Condition
CE = OE
= V
IL
OE = V
IL
CE = V
IL
Min
Max
70
70
30
20
t
OH
Note:
0
0
0
0
ns
2, 3, 4, 5 - see AC Waveforms for Read Operation
4
AT27C040
AT27C040
AC Waveforms for Read Operation
(1)
Notes:
1.
2.
3.
4.
5.
Tiiming measurement references are 0.8V and 2.0V. Input AC drive levels are 0.45V and 2.4V, unless otherwise specified.
OE may be delayed up to t
CE
- t
OE
after the falling edge of CE without impact on t
CE
.
OE may be delayed up to t
ACC
- t
OE
after the address is valid without impact on t
ACC
.
This parameter is only sampled and is not 100% tested.
Output float is defined as the point when data is no longer driven.
Input Test Waveforms and Measurement Levels
Output Test Load
Pin Capacitance
(f = 1 MHz, T = 25°C)
(1)
Typ
C
IN
C
OUT
Note:
4
8
Max
8
12
Units
pF
pF
Conditions
V
IN
= 0V
V
OUT
= 0V
1. Typical values for nominal supply voltage. This parameter is only sampled and is not 100% tested.
5
