NM27C256 262,144-Bit (32K x 8) High Performance CMOS EPROM
Programming Characteristics
(Note 12) (Note 13) (Note 14) (Note 15) (Continued)
Symbol
t
AS
t
OES
t
VPS
t
VCS
t
DS
t
AH
t
DH
t
DF
t
PW
t
OE
I
PP
I
CC
T
A
V
CC
V
PP
t
FR
V
IL
V
IH
t
IN
t
OUT
Parameter
Address Setup Time
OE Setup Time
V
PP
Setup Time
V
CC
Setup Time
Data Setup Time
Address Hold Time
Data Hold Time
Output Enable to Output
Float Delay
Program Pulse Width
Data Valid from OE
V
PP
Supply Current
during Programming Pulse
V
CC
Supply Current
Temperature Ambient
Power Supply Voltage
Programming Supply Voltage
Input Rise, Fall Time
Input Low Voltage
Input High Voltage
Input Timing Reference Voltage
Output Timing Reference Voltage
Conditions
Min
1
1
1
1
1
0
1
Typ
Max
Units
µs
µs
µs
µs
µs
µs
µs
CE = V
IL
0
45
50
60
105
100
30
50
ns
µs
ns
mA
mA
°C
V
V
ns
CE = V
IL
CE = V
IL
20
6.25
12.5
5
25
6.5
12.75
30
6.75
13.0
0.0
2.4
0.8
0.8
4.0
0.45
V
V
2.0
2.0
V
V
Programming Waveforms
(Note 14)
PROGRAM
PROGRAM
VERIFY
ADDRESSES
2.0V
0.8V
t
AS
ADDRESS N
t
AH
DATA IN STABLE
ADD N
t
DS
t
DH
DATA OUT VALID
ADD N
t
DF
DATA
2.0V
0.8V
V
CC
5.25V
t
VCS
V
PP
12.75V
t
VPS
2.0V
0.8V
t
OES
t
PW
t
OE
CE
OE
2.0V
0.8V
DS010833-5
Note 12:
Fairchild’s standard product warranty applies to devices programmed to specifications described herein.
Note 13:
V
CC
must be applied simultaneously or before V
PP
and removed simultaneously or after V
PP
. The EPROM must not be inserted into or removed from a board with
voltage applied to V
PP
or V
CC
.
Note 14:
The maximum absolute allowable voltage which may be applied to the V
PP
pin during programming is 14V. Care must be taken when switching the V
PP
supply to
prevent any overshoot from exceeding this 14V maximum specification. At least a 0.1
µF
capacitor is required across V
PP
, V
CC
to GND to suppress spurious voltage transients
which may damage the device.
Note 15:
During power up the PGM pin must be brought high (≥ V
IH
) either coincident with or before power is applied to V
PP
.
5
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