FINAL

Publication# 11507

Rev: H Amendment/0

Issue Date: May 1998

Am27C020

2 Megabit (256 K x 8-Bit) CMOS EPROM

DISTINCTIVE CHARACTERISTICS

Fast access time

-- Speed options as fast as 55 ns

Low power consumption

-- 100 µA maximum CMOS standby current

JEDEC-approved pinout

-- Plug in upgrade of 1 Mbit EPROM

-- Easy upgrade from 28-pin JEDEC EPROMs

Single +5 V power supply

10% power supply tolerance standard

100% FlashriteTM programming

-- Typical programming time of 32 seconds

Latch-up protected to 100 mA from 1 V to
V

+ 1 V

High noise immunity

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

11507H-1

A0A17

Address

Inputs

PGM#

CE#

OE#

Data Outputs

DQ0DQ7

Output

Buffers

Gating

2,097,152

Bit Cell

Matrix

Decoder

Output Enable

Chip Enable

and

Prog Logic

Am27C020

PRODUCT SELECTOR GUIDE

CONNECTION DIAGRAMS

Top View

DIP

PLCC

Notes:
1. JEDEC nomenclature is in parenthesis.

2. The 32-pin DIP to 32-pin PLCC configuration varies from the JEDEC 28-pin DIP to 32-pin PLCC configuration.

PIN DESIGNATIONS

A0A17

= Address Inputs

CE# (E#)

= Chip Enable Input

DQ0DQ7

= Data Input/Outputs

OE# (G#)

= Output Enable Input

PGM# (P#)

= Program Enable Input

= V

Supply Voltage

= Program Voltage Input

= Ground

LOGIC SYMBOL

Family Part Number

Am27C020

Speed Options

= 5.0 V

-55

-75

-255

= 5.0 V

10%

-70

-90

-120

-150

-200

Max Access Time (ns)

120

150

200

250

CE# (E#) Access (ns)

120

150

200

250

OE# (G#) Access (ns)

100

A16

DQ0

A15

A12

DQ1

DQ2

A11

OE# (G#)

A10

CE# (E#)

DQ7

PGM# (P#)

DQ6

A17

A14

A13

DQ5

DQ4

DQ3

11507H-2

DQ6

DQ5

DQ4

DQ3

31 30

17 18 19 20

DQ0

A14

A13

A11

OE# (G#)

A10

CE# (E#)

DQ7

A12

A15

A16

PGM# (P#)

A17

DQ1

DQ2

11507H-3

DQ0DQ7

A0A17

CE# (E#)

OE# (G#)

11507H-4

PGM# (P#)

Am27C020

ORDERING INFORMATION

UV EPROM Products

AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed
by a combination of the following:

Valid Combinations

Valid Combinations list configurations planned to be sup-
ported in volume for this device. Consult the local AMD sales
office to confirm availability of specific valid combinations and
to check on newly released combinations.

DEVICE NUMBER/DESCRIPTION
Am27C020
2 Megabit (256 K x 8-Bit) CMOS UV EPROM

AM27C020

-55

OPTIONAL PROCESSING
Blank = Standard Processing
B

= Burn-In

VOLTAGE TOLERANCE
5

= V

5%, 55 ns only

See Product Selector Guide and Valid Combinations

TEMPERATURE RANGE
C = Commercial (0

C to +70

= Industrial (40

C to +85

= Extended (55

C to +125

PACKAGE TYPE
D = 32-Pin Ceramic DIP (CDV032)

SPEED OPTION
See Product Selector Guide and Valid Combinations

Valid Combinations

AM27C020-55

= 5.0 V

DC5, DC5B, DI5, DI5B

AM27C020-55

= 5.0 V

10%

DC, DCB, DI, DIB

AM27C020-70

AM27C020-90

AM27C020-120

DC, DCB, DI, DIB, DE, DEB

AM27C020-150

AM27C020-200

AM27C020-255

= 5.0 V

DC, DCB, DI, DIB

Am27C020

ORDERING INFORMATION

OTP EPROM Products

AMD standard products are available in several packages and operating ranges. The order number (Valid Combination) is formed
by a combination of the following:

Valid Combinations

DEVICE NUMBER/DESCRIPTION
Am27C020
2 Megabit (256 K x 8-Bit) CMOS OTP EPROM

AM27C020

-55

OPTIONAL PROCESSING
Blank = Standard Processing

VOLTAGE TOLERANCE
5

= V

5%, 55 ns only

See Product Selector Guide and Valid Combinations

TEMPERATURE RANGE
C = Commercial (0

C to +70

= Industrial (40

C to +85

PACKAGE TYPE
P

= 32-Pin Plastic DIP (PD 032)

= 32-Pin Plastic Leaded Chip Carrier (PL 032)

SPEED OPTION
See Product Selector Guide and Valid Combinations

Valid Combinations

AM27C020-55

= 5.0 V

PC5, PI5, JC5, JI5

AM27C020-55

= 5.0 V

10%

JC, PC, JI, PI

AM27C020-75

AM27C020-90

AM27C020-120

AM27C020-150

AM27C020-200

AM27C020-255

= 5.0 V

Am27C020

FUNCTIONAL DESCRIPTION

Device Erasure

In order to clear all locations of their programmed con-
tents, the device must be exposed to an ultraviolet light
source. A dosage of 15 W seconds/cm

is required to

completely erase the device. This dosage can be ob-
tained by exposure to an ultraviolet lamp--wavelength
of 2537 Å--with intensity of 12,000 µW/cm

for 15 to 20

minutes. The device should be directly under and about
one inch from the source, and all filters should be re-
moved from the UV light source prior to erasure.

Note that all UV erasable devices will erase with light
sources having wavelengths shorter than 4000 Å, such
as fluorescent light and sunlight. Although the erasure
process happens over a much longer time period, ex-
posure to any light source should be prevented for
maximum system reliability. Simply cover the package
window with an opaque label or substance.

Device Programming

Upon delivery, or after each erasure, the device has
all of its bits in the "ONE", or HIGH state. "ZEROs" are
loaded into the device through the programming pro-
cedure.

The device enters the programming mode when 12.75
V

0.25 V is applied to the V

pin, and CE# and

PGM# are at V

and OE# is at V

For programming, the data to be programmed is ap-
plied 8 bits in parallel to the data pins.

The flowchar t in the Programming section of the
EPROM Products Data Book (Section 5, Figure 5-1)
shows AMD's Flashrite algorithm. The Flashrite algo-
rithm reduces programming time by using a 100 µs pro-
gramming pulse and by giving each address only as
many pulses to reliably program the data. After each
pulse is applied to a given address, the data in that ad-
dress is verified. If the data does not verify, additional
pulses are given until it verifies or the maximum pulses
allowed is reached. This process is repeated while se-
quencing through each address of the device. This part
of the algorithm is done at V

= 6.25 V to assure that

each EPROM bit is programmed to a sufficiently high
threshold voltage. After the final address is completed,
the entire EPROM memory is verified at V

= V

5.25 V.

Please refer to Section 5 of the EPROM Products Data
Book for additional programming information and spec-
ifications.

Program Inhibit

Programming different data to multiple devices in par-
allel is easily accomplished. Except for CE#, all like in-
puts of the devices may be common. A TTL low-level
program pulse applied to one device's CE# input with

= 12.75 V

0.25 V and PGM# LOW, and OE#

HIGH will program that particular device. A high-level
CE# input inhibits the other devices from being pro-
grammed.

Program Verify

A verification should be performed on the programmed
bits to determine that they were correctly programmed.
The verify should be performed with OE# and CE#, at
V

, PGM# at V

, and V

between 12.5 V and 13.0 V.

Autoselect Mode

The autoselect mode provides manufacturer and de-
vice identification through identifier codes on DQ0
DQ7. This mode is primarily intended for programming
equipment to automatically match a device to be pro-
grammed with its corresponding programming algo-
rithm. This mode is functional in the 25

ambient temperature range that is required when pro-
gramming the device.

To activate this mode, the programming equipment
must force V

on address line A9. Two identifier bytes

may then be sequenced from the device outputs by tog-
gling address line A0 from V

to V

(that is, changing

the address from 00h to 01h). All other address lines
must be held at V

during the autoselect mode.

Byte 0 (A0 = V

) represents the manufacturer code,

and Byte 1 (A0 = V

), the device identifier code. Both

codes have odd parity, with DQ7 as the parity bit.

Read Mode

To obtain data at the device outputs, Chip Enable (CE#)
and Output Enable (OE#) must be driven low. CE# con-
trols the power to the device and is typically used to se-
lect the device. OE# enables the device to output data,
independent of device selection. Addresses must be
stable for at least t

ACC

Refer to the Switching

Waveforms section for the timing diagram.

Standby Mode

The device enters the CMOS standby mode when CE#
is at V

0.3 V. Maximum V

current is reduced to

100 µA. The device enters the TTL-standby mode
when CE# is at V

. Maximum V

current is reduced

to 1.0 mA. When in either standby mode, the device
places its outputs in a high-impedance state, indepen-
dent of the OE# input.

Output OR-Tieing

To accommodate multiple memory connections, a
two-line control function provides:

Low memory power dissipation, and

Assurance that output bus contention will not occur.

Am27C020

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-

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

and V

to minimize transient effects. In addition,

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

and V

for each eight devices. The loca-

tion of the capacitor should be close to where the
power supply is connected to the array.

MODE SELECT TABLE

Notes:
1. V

= 12.0 V

0.5 V.

2. X = Either V

or V

3. A1A8 and A1017 = V

4. See DC Programming Characteristics for V

voltage during programming.

Mode

CE#

OE#

PGM#

Outputs

Read

OUT

Output Disable

High Z

Standby (TTL)

High Z

Standby (CMOS)

0.3 V

High Z

Program

Program Verify

OUT

Program Inhibit

High Z

Autoselect
(Note 3)

Manufacturer Code

01h

Device Code

97h

Am27C020

ABSOLUTE MAXIMUM RATINGS

Storage Temperature
OTP Products. . . . . . . . . . . . . . . . . . 65

C to +125

All Other Products . . . . . . . . . . . . . . 65

C to +150

Ambient Temperature
with Power Applied. . . . . . . . . . . . . . 55

C to +125

Voltage with Respect to V

All pins except A9, V

, V

. . 0.6 V to V

+ 0.6 V

A9 and V

(Note 2) . . . . . . . . . . . . . 0.6 V to 13.5 V

(Note 1). . . . . . . . . . . . . . . . . . . . . 0.6 V to 7.0 V

Notes:

1. Minimum DC voltage on input or I/O pins 0.5 V. During

voltage transitions, the input may overshoot V

to 2.0 V

for periods of up to 20 ns. Maximum DC voltage on input
and I/O pins is V

+ 5 V. During voltage transitions, input

and I/O pins may overshoot to V

+ 2.0 V for periods up

to 20 ns.

2. Minimum DC input voltage on A9 is 0.5 V. During voltage

transitions, A9 and V

may overshoot V

to 2.0 V for

periods of up to 20 ns. A9 and V

must not exceed +13.5

V at any time.

Stresses above those listed under "Absolute Maximum Rat-
ings" may cause permanent damage to the device. This is a
stress rating only; functional operation of the device at these
or any other conditions above those indicated in the opera-
tional sections of this specification is not implied. Exposure of
the device to absolute maximum ratings for extended periods
may affect device reliability.

OPERATING RANGES

Commercial (C) Devices

Ambient Temperature (T

) . . . . . . . . . . .0

C to +70

Industrial (I) Devices

Ambient Temperature (T

) . . . . . . . . .40

C to +85

Extended (E) Devices

Ambient Temperature (T

) . . . . . . . .55

C to +125

Supply Read Voltages

for ± 5% devices . . . . . . . . . . +4.75 V to +5.25 V

for ± 10% devices . . . . . . . . . +4.50 V to +5.50 V

Operating ranges define those limits between which the func-
tionality of the device is guaranteed.

Am27C020

DC CHARACTERISTICS over operating range (unless otherwise specified)

Caution: The device must not be removed from (or inserted into) a socket when V

or V

is applied.

Notes:
1. V

must be applied simultaneously or before V

, and removed simultaneously or after V

2. I

CC1

is tested with OE# = V

to simulate open outputs.

3. Minimum DC Input Voltage is 0.5 V. During transitions, the inputs may overshoot to 2.0 V for periods less than 20 ns.

Maximum DC Voltage on output pins is V

+ 0.5 V, which may overshoot to V

+ 2.0 V for periods less than 20 ns.

Figure 1.

Typical Supply Current vs. Frequency

= 5.5 V, T = 25

Figure 2.

Typical Supply Current vs. Temperature

= 5.5 V, f = 10 MHz

Parameter

Symbol

Parameter Description

Test Conditions

Min

Max

Unit

Output HIGH Voltage

= 400 µA

2.4

Output LOW Voltage

= 2.1 mA

0.45

Input HIGH Voltage

2.0

+ 0.5

Input LOW Voltage

0.5

+0.8

Input Load Current

= 0 V to V

1.0

Output Leakage Current

OUT

= 0 V to V

5.0

µA

CC1

Active Current (Note 2)

CE# = V

, f = 10 MHz,

OUT

= 0 mA

C/I Devices

E Devices

CC2

TTL Standby Current

CE# = V

1.0

CC3

CMOS Standby Current

CE# = V

0.3 V

100

µA

PP1

Supply Current (Read)

CE# = OE# = V

, V

= V

100

µA

11507H-5

Frequency in MHz

pply

rre

11507H-6

75 50 55

75 100 125 150

Temperature in

Sup

ply

rre

Am27C020

TEST CONDITIONS

Table 1.

Test Specifications

SWITCHING TEST WAVEFORM

KEY TO SWITCHING WAVEFORMS

2.7 k

6.2 k

5.0 V

Device

Under

Test

11507H-7

Figure 3.

Test Setup

Note:
Diodes are IN3064 or equivalents.

Test Condition

-55

All

Unit

Output Load

1 TTL gate

Output Load Capacitance, C

(including jig capacitance)

100

Input Rise and Fall Times

Input Pulse Levels

0.03.0 0.452.4

Input timing measurement
reference levels

1.5

0.8, 2.0

Output timing measurement
reference levels

1.5

0.8, 2.0

2.4 V

0.45 V

Input

Output

Test Points

2.0 V

0.8 V

11507H-8

3 V

0 V

Input

Output

1.5 V

Test Points

Note: For C

= 100 pF.

Note: For C

= 30 pF.

KS000010-PAL

WAVEFORM

INPUTS

OUTPUTS

Steady

Changing from H to L

Changing from L to H

Don't Care, Any Change Permitted

Changing, State Unknown

Does Not Apply

Center Line is High Impedance State (High Z)

Am27C020

AC CHARACTERISTICS

Caution: Do not remove the device from (or insert it into) a socket or board that has V

or V

applied.

Notes:

1. V

must be applied simultaneously or before V

, and removed simultaneously or after V

2. This parameter is sampled and not 100% tested.

3. Switching characteristics are over operating range, unless otherwise specified.

4. See Figure 3 and Table 1 for test specifications.

SWITCHING WAVEFORMS

Notes:
1. OE# may be delayed up to t

ACC

after the falling edge of the addresses without impact on t

ACC

2. t

is specified from OE# or CE#, whichever occurs first.

PACKAGE CAPACITANCE

Notes:
1. This parameter is only sampled and not 100% tested.

2. T

= +25

C, f = 1 MHz.

Parameter Symbols

Description

Test Setup

Am27C020

Unit

JEDEC

Standard

-55

-75
-70

-90

-120 -150 -200 -255

AVQV

ACC

Address to Output Delay

CE#,
OE# = V

Max

120

150

200

250

ELQV

Chip Enable to Output Delay

OE# = V

Max

120

150

200

250

GLQV

Output Enable to Output Delay CE# = V

Max

100

EHQZ

GHQZ

(Note 2)

Chip Enable High or Output
Enable High to Output High Z,
Whichever Occurs First

Max

AXQX

Output Hold Time from
Addresses, CE# or OE#,
Whichever Occurs First

Min

Addresses

CE#

OE#

Output

11507H-9

Addresses Valid

High Z

Valid Output

2.4

0.45

2.0
0.8

ACC

(Note 1)

(Note 2)

Parameter Symbol

Parameter

Description

Test Conditions

CDV032

PD 032

PL 032

Unit

Typ

Max

Typ

Max

Typ

Max

Input Capacitance

= 0

OUT

Output Capacitance

OUT

= 0

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Document Outline

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Document Outline

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