Rainbow Electronics AT27C256R User Manual

Features

•

Fast Read Access Time - 45 ns

•

Low-Power CMOS Operation

µµµµ

– 100

A max. Standby

– 20 mA max. Active at 5 MHz

•

JEDEC Standard Packages

– 28-Lead 600-mil PDIP
– 32-Lead PLCC
– 28-Lead TSOP and SOIC

±

•

5V

10% Supply

•

High Reliability CMOS Technology

– 2,000V ESD Protection
– 200 mA Latchup Immunity

•

Rapid™ Programming Algorithm - 100

•

CMOS and TTL Compatible Inputs and Outputs

•

Integrated Product Identification Code

•

Commercial, Industrial and Automotive Temperature Ranges

µµµµ

s/byte (typical)

Description

The AT27C256R is a low- pow er , high- pe rf orman ce 262,144-bit one-time pro gramm a­ble read only memory (OTP EPROM) organized 32K by 8 bits. It requires only one 5V
power supply in norm al read mo de operat ion. Any byt e can be acc essed in less than
45 ns, eliminating the n eed for speed reducing WAIT s tates on high-pe rformance
microprocessor systems.

Atmel’s scaled CMOS technolo gy provide s low-acti ve power c onsumptio n, and fast
programming. Power consumption is typically only 8 mA in Active Mode and less than
10 µA in Standby.

(continued)

Pin Configurations

Pin Name Function

A0 to A14 Addresses
O0 - O7 Outputs
CE
OE
NC No Connect

PLCC Top View

5

A6

6

A5

7

A4

8

A3

9

A2

10

A1

11

A0

12

NC

13

O0

Note: PLCC Package Pins 1 and

17 are DON’T CONNECT.

Chip Enable
Output En able

A7

A12

VPPNCVCC

A14

432

1

323130

14151617181920

O1

O2

O3O4O5

NC

GND

A13

29
28
27
26
25
24
23
22
21

A8
A9
A11
NC
OE
A10
CE
O7
O6

A11

A13

A14
VCC
VPP

A12

PDIP, SOIC Top View

VPP

A12

A7
A6
A5
A4
A3
A2
A1
A0
O0
O1
O2

GND

TSOP Top View

OE

22
23

A9

24

A8

25
26
27
28

1
2
3

A7

4

A6

5

A5

6

A4

7

A3

1
2
3
4
5
6
7
8
9
10
11
12
13
14

Type 1

28

VCC

27

A14

26

A13

25

A8

24

A9

23

A11

22

OE

21

A10

20

CE

19

O7

18

O6

17

O5

16

O4

15

O3

21

A10

20

CE

19

O7

18

O6

17

O5

16

O4

15

O3

14

GND

13

O2

12

O1

11

O0

10

A0

9

A1

8

A2

256K (32K x 8)
OTP EPROM

AT27C256R

256K EPROM

Rev. 0014H–07/98

1

The AT27C256 R is ava ilable in a c hoice of indu stry st an­dard JEDEC-approved one time programmable (OTP)
plastic DIP, PLCC, SOIC, and TSOP packages. All devices
feature two-line control (CE
ibility to prevent bus contention.

With 32K byte storage capability, the AT27C256R allows
firmware to be stored reliably and to be accessed by the
system without the delays of mass storage media.

Atmel’s 27C256R has addit ional features to ensure high
quality and efficient producti on use. The Rapi d™ Progra m­ming Algori thm reduc es the time require d to prog ram the
part and guarantees reliable programming. Programming
time is typically only 100 µs/byte. The Integrated Product
Identification Code electronica lly identifi es the devic e and
manufacturer. This feature is used by industry standard
programming equi pmen t to se lect the prop er progr ammi ng
algorithms and voltages.

, OE) to give designers the flex-

System Considerations

Switching between active and standby conditions via the
Chip Enable pin may produ ce tra ns ien t vo ltag e ex cu rs i ons .
Unless accommodated by the system design, these tran­sients may exceed data sheet limits, resulting in device
non-conformance. At a minimum, a 0.1 µF high frequency,
low inherent inductance, ceramic capacitor should be uti­lized for each device. This capacitor should be connected
between the V
close to the device as possible. Additionally, to stabilize the
supply voltage level on printed circuit boards with large
EPROM arrays, a 4.7 µF bulk electrolytic capacitor should
be utilized, again connected between the V
terminals. This capacitor should be positioned as close as
possible to the point where the power supply is connected
to the array.

and Ground terminals of the device, as

CC

and Ground

CC

2

AT27C256R

Block Diagram

Absolute Maximum Ratings*

Temperature Under Bias................................ -55°C to +125°C

Storage Temperature.....................................-65°C to +150°C

Voltage on Any Pin with

Respect to Ground .........................................-2.0V to +7.0V

Voltage on A9 with

Respect to Ground ......................................-2.0V to +14.0V

VPP Supply Voltage with

Respect to Ground .......................................-2.0V to +14.0V

AT27C256R

*NOTICE: Stresses beyond those listed under “Absolute Maxi-

mum Ratings” may cause permanent damage to
the device. This is a stress rating only and func­tional operation of the device at these or any other

(1)

(1)

Note: 1 . Minimum voltage is -0.6V dc which ma y unde rshoot

(1)

conditions beyond those indicated in the opera­tional sections of this specification is not implied.
Exposure to absolute maximum rating conditions
for extended periods may affect device reliability.

to -2.0V for pulses of les s than 20 ns .Maximum out­put pin voltage is V

+ 0.75V dc which may over-

CC

shoot to +7.0 volts for pulses of less than 20 ns.

Operating Modes

Mode\Pin CE OE Ai V

Read V
Output Disable V
Standby V
Rapid Program
PGM Verify
Optional PGM Verify
PGM Inhibit

Product Identification

(2)

(2)

(2)

(2)

(4)

Notes: 1. X can be VIL or VIH.

2. Refer to Programming Characteristics.
= 12.0 ± 0.5V.

3. V

H

4. T wo identifier bytes may be selected. All Ai inputs are held low (VIL), except A9 which is set to VH and A0 which is toggle d low

) to select the Manufacturer’s Identification byte and high (VIH) to select the Device Code byte.

(V

IL

IL

IL

IH

V

IL

(1)

X

V

IL

V

IH

V

IL

V

IL

V

IH

(1)

X

V

IH

V

IL

V

IL

V

IH

V

IL

Ai V

(1)

X

(1)

X
Ai V
Ai V
Ai V

(1)

X

A9 = V

(3)

H

A0 = VIH or VIL
A1 - A14 = V

IL

V

PP

CC

V

CC

V

CC

PP

PP

CC

V

PP

CC

Outputs

D

OUT

High Z
High Z
D

IN

D

OUT

D

OUT

High Z

Identification Code

3

DC and AC Operating Conditions for Read Operation

AT27C256R

-45 -55 -70 -90 -12 -15

Com. 0°C - 70°C0°C - 70°C0°C - 70°C0°C - 70°C0°C - 70°C0°C - 70°C
Operating
Temp. (Case)

Ind. -40°C - 85°C-40°C - 85°C-40°C - 85°C-40°C - 85°C-40°C - 85°C-40°C - 85°C

Auto. -40°C - 125°C-40°C - 125°C-40°C - 125°C-40°C - 125°C
V

Supply 5V ± 10% 5V ± 10% 5V ± 10% 5V ± 10% 5V ± 10% 5V ± 10%

CC

DC and Operating Characteristics for Read Operation

Symbol Parameter Condition Min Max Units

I

LI

Input Load Current VIN = 0V to V

CC

Com., Ind. ±1 µA
Auto. ±5 µA

I

I

I

I
V
V
V
V

LO

PP1

SB

CC

IL

IH

OL

OH

(2)

Output Leakage Current V

(1)

V

Read/Standby Current VPP = V

PP

(1)

V

Standby Current

CC

VCC Active Current f = 5 MHz, I

= 0V to V

OUT

(CMOS), CE = VCC ± 0.3V 100 µA

I

SB1

I

(TTL), CE = 2.0 to V

SB2

CC

OUT

CC

CC

= 0 mA, E = V

Auto. ±10 µA

10 µA

+ 0.5V 1 mA

IL

20 mA
Input Low Voltage -0.6 0.8 V
Input High Voltage 2.0 VCC + 0.5 V
Output Low Voltage IOL = 2.1 mA 0.4 V
Output High Voltage IOH = -400 µA2.4V

Notes: 1. VCC must be applied simultaneously with or before VPP, and removed simultaneously with or after VPP..

Com., Ind. ±5 µA

may be connected directly to VCC, except d uring p r og r amming. The suppl y c urre nt w o ul d th en be the sum of ICC and IPP..

2. V

PP

AC Characteristics for Read Operat ion

AT27C256R

-45 -55 -70 -90 -12 -15

Symbol Parameter Condition Min Max Min Max Min Max Min Max Min Max Min Max

(3)

t
t
t

t

ACC

CE

OE

DF

(2)

(2)(3)

(4)(5)

Address to Output Delay CE = OE = V
CE to Output Delay OE = V
OE to Output Delay CE = V

IL

IL

OE or CE High to Output
Float, whichever occurred first

IL

45 55 70 90 120 150 ns
45 55 70 90 120 150 ns
20 25 30 30 35 40 ns

20 20 25 25 30 35 ns

Units

t

OH

Output Hold from Address, CE or OE,
whichever occurred first

777000ns

Note: 2, 3, 4, 5. - see AC Waveforms for Read Operation.

4

AT27C256R