AM27C020 Advanced Micro Devices, AM27C020 Datasheet - Page 6

• Manufacturer Part Number: AM27C020
• Description: 2 Megabit (256 K x 8-Bit) CMOS EPROM
• Manufacturer: Advanced Micro Devices

CE# should be decoded and used as the primary de-
vice-selecting function, while OE# be made a common
connection to all devices in the array and connected to
the READ line from the system control bus. This as-
sures that all deselected memory devices are in their
low-power standby mode and that the output pins are
only active when data is desired from a particular mem-
ory device.
System Applications
During the switch between active and standby condi-
tions, transient current peaks are produced on the ris-
MODE SELECT TABLE
Notes:
1. V
2. X = Either V
3. A1–A8 and A10–17 = V
4. See DC Programming Characteristics for V
6
Mode
Read
Output Disable
Standby (TTL)
Standby (CMOS)
Program
Program Verify
Program Inhibit
Autoselect
(Note 3)
H
= 12.0 V
Manufacturer Code
Device Code
IH
0.5 V.
or V
IL
.
IL
V
CC
CE#
V
V
V
V
V
V
V
X
IH
IH
IL
IL
IL
IL
IL
0.3 V
PP
voltage during programming.
Am27C020
OE#
V
V
V
V
V
V
X
X
X
IH
IH
IL
IL
IL
IL
ing and falling edges of Chip Enable. The magnitude of
these transient current peaks is dependent on the out-
put capacitance loading of the device. At a minimum, a
0.1 µF ceramic capacitor (high frequency, low inherent
inductance) should be used on each device between
V
to overcome the voltage drop caused by the inductive
effects of the printed circuit board traces on EPROM ar-
rays, a 4.7 µF bulk electrolytic capacitor should be used
between V
tion of the capacitor should be close to where the
power supply is connected to the array.
CC
PGM#
V
V
X
X
X
X
X
X
X
IL
IH
and V
CC
SS
V
A0
V
and V
to minimize transient effects. In addition,
X
X
X
X
X
X
X
IH
IL
SS
for each eight devices. The loca-
A9
V
V
X
X
X
X
X
X
X
H
H
V
V
V
V
X
X
X
X
X
X
PP
PP
PP
PP
Outputs
High Z
High Z
High Z
High Z
D
D
01h
97h
D
OUT
OUT
IN