FINAL
Publication# 17502 Rev: D Amendment/+1
Issue Date: January 1998
Am28F020A
2 Megabit (256 K x 8-Bit)
CMOS 12.0 Volt, Bulk Erase Flash Memory with Embedded Algorithms
DISTINCTIVE CHARACTERISTICS
a73 High performance
— Access times as fast as 70 ns
a73 CMOS low power consumption
— 30 mA maximum active current
— 100 µA maximum standby current
— No data retention power consumption
a73 Compatible with JEDEC-standard byte-wide
32-pin EPROM pinouts
— 32-pin PDIP
— 32-pin PLCC
— 32-pin TSOP
a73 100,000 write/erase cycles minimum
a73 Write and erase voltage 12.0 V ±5%
a73 Latch-up protected to 100 mA from
–1 V to V
CC
+1 V
a73 Embedded Erase Electrical Bulk Chip Erase
— Five seconds typical chip erase, including
pre-programming
a73 Embedded Program
— 14 µs typical byte program, including time-out
— 4 seconds typical chip program
a73 Command register architecture for
microprocessor/microcontroller compatible
write interface
a73 On-chip address and data latches
a73 Advanced CMOS flash memory technology
— Low cost single transistor memory cell
a73 Embedded algorithms for completely self-timed
write/erase operations
GENERAL DESCRIPTION
The Am28F020A is a 2 Megabit Flash memory orga-
nized as 256 Kbytes of 8 bits each. AMD’s Flash mem-
ories offer the most cost-effective and reliable read/
write non-volatile random access memory. The
Am28F020A is packaged in 32-pin PDIP, PLCC, and
TSOP versions. It is designed to be reprogrammed and
erased in-system or in standard EPROM programmers.
The Am28F020A is erased when shipped from
the factory.
The standard Am28F020A offers access times of as
fast as 70 ns, allowing high speed microprocessors to
operate without wait states. To eliminate bus conten-
tion, the device has separate chip enable (CE#) and
output enable (OE#) controls.
AMD’s Flash memories augment EPROM functionality
with in-circuit electrical erasure and programming. The
Am28F020A uses a command register to manage this
functionality. The command register allows for 100%
TTL level control inputs and fixed power supply levels
during erase and programming, while maintaining
maximum EPROM compatibility.
The Am28F020A is compatible with the AMD
Am28F256A, Am28F512A, and Am28F010A Flash
memories. All devices in the Am28Fxxx family follow
the JEDEC 32-pin pinout standard. In addition, all
devices within this family that offer Embedded Algo-
rithms use the same command set. This offers
designers the flexibility to retain the same device foot-
print and command set, at any density between
256 Kbits and 2 Mbits.
AMD’s Flash technology reliably stores memory con-
tents even after 100,000 erase and program cycles.
The AMD cell is designed to optimize the erase and
programming mechanisms. In addition, the combina-
tion of advanced tunnel oxide processing and low
internal electric fields for erase and programming oper-
ations produces reliable cycling. The Am28F020A uses
a 12.0±5% V
PP
supply input to perform the erase and
programming functions.
The highest degree of latch-up protection is achieved
with AMD’s proprietary non-epi process. Latch-up pro-
tection is provided for stresses up to 100 mA on
address and data pins from –1 V to V
CC
+1 V.
AMD’s Flash technology combines years of EPROM
and EEPROM experience to produce the highest levels
of quality, reliability, and cost effectiveness. The
Am28F020A electrically erases all bits simultaneously
using Fowler-Nordheim tunneling. The bytes are
programmed one byte at a time using the EPROM
programming mechanism of hot electron injection.