11507H-1
A0–A17
Address
Inputs
2,097,152
Bit Cell
Matrix
X
Decoder
FINAL
Am27C020
2 Megabit (256 K x 8-Bit) CMOS EPROM
DISTINCTIVE CHARACTERISTICS
a73 Fast access time
— Speed options as fast as 55 ns
a73 Low power consumption
— 100 µA maximum CMOS standby current
a73 JEDEC-approved pinout
— Plug in upgrade of 1 Mbit EPROM
— Easy upgrade from 28-pin JEDEC EPROMs
a73 Single +5 V power supply
a73 ±10% power supply tolerance standard
a73 100% Flashrite™ programming
— Typical programming time of 32 seconds
a73 Latch-up protected to 100 mA from –1 V to
V
CC
+ 1 V
a73 High noise immunity
a73 Compact 32-pin DIP, PDIP, and PLCC packages
GENERAL DESCRIPTION
The Am27C020 is a 2 Megabit, ultraviolet erasable pro-
grammable read-only memory. It is organized as 256
Kwords by 8 bits per word, operates from a single +5 V
supply, has a static standby mode, and features fast
single address location programming. Products are
available in windowed ceramic DIP packages, as well
as plastic one time programmable (OTP) PDIP and
PLCC packages.
Data can be typically accessed in less than 55 ns, al-
lowing high-performance microprocessors to operate
without any WAIT states. The device offers separate
Output Enable (OE#) and Chip Enable (CE#) controls,
thus eliminating bus contention in a multiple bus micro-
processor system.
AMD’s CMOS process technology provides high
speed, low power, and high noise immunity. Typical
power consumption is only 100 mW in active mode,
and 100 µW in standby mode.
All signals are TTL levels, including programming sig-
nals. Bit locations may be programmed singly, in
blocks, or at random. The device supports AMD’s
Flashrite programming algorithm (100 µs pulses), re-
sulting in a typical programming time of 32 seconds.
BLOCK DIAGRAM
PGM#
CE#
OE#
V
CC
V
SS
V
PP
Data Outputs
DQ0–DQ7
Output
Buffers
Y
Gating
Y
Decoder
Output Enable
Chip Enable
and
Prog Logic
Publication# 11507 Rev: H Amendment/0
Issue Date: May 1998