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EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

FEATURES

•

Fast Read Access Time

45, -55, -70, and -90ns

•

Single 5V Power Supply

•

Programming Voltage +12.75V

•

QuikRite

Programming Algorithm

•

Typical programming time 20

•

Low Power CMOS Operation

•

A Standby (Typical)

•

30mA Operation (Max.)

•

CMOS- and TTL-Compatible I/O

•

High-Reliability CMOS Technology

•

Latch-Up Immunity to 100mA

from -1V to V

+ 1V

•

Two-Line Control (

)

•

Standard Product Identification Code

•

JEDEC Standard Pinout

•

28-pin PDIP

•

32-pin PLCC

•

28-pin TSOP (Type 1)

•

Commercial and Industrial Temperature

Ranges

GENERAL DESCRIPTION

The EN27C512 is a low-power 512Kbit, 5V-only one-time-programmable (OTP) read-only

memory (EPROM). Organized into 64K words with 8 bits per word, it features QuikRite

single-

address location programming, typically at 20

s per byte. Any byte can be accessed in less than

45ns, eliminating the need for WAIT states in high-performance microprocessor systems. The

EN27C512 has separate Output Enable (

) and Chip Enable (

) controls which eliminate

bus contention issues.

FIGURE 1. PDIP

Pin Name

Function

A0-A15

Addresses

DQ0-DQ7

Outputs

Chip Enable

Output Enable

No Connect

EN27C512 512KBIT EPROM (64K x 8)

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

FIGURE 4. BLOCK DIAGRAM

FUNCTIONAL DESCRIPTION

THE QUIKRITE

PROGRAMMING OF THE EN27C512

When the EN27C512 is delivered, the chip has all 512K bits in the “ONE”, or

HIGH state. “ZEROs” are loaded into the EN27C512 through the procedure of programming.

The programming mode is entered when 12.75

0.25V is applied to the

pin and

is at V

. For programming, the data to be programmed is applied with 8 bits in parallel to

the data pins.

The QUIKRITE

programming flowchart in Figure 5 shows Eon’s interactive programming

algorithm. The interactive algorithm reduces programming time by using 20

s to 100

programming pulses and giving each address only as many pulses as is necessary in order to

reliably program the data. After each pulse is applied to a given address, the data in that

address is verified. If the data is not verified, additional pulses are given until it is verified or

until the maximum number of pulses is reached. This process is repeated while sequencing

through each address of the EN27C512. This part of the programming algorithm is done at

= 6.25V to assure that each EPROM bit is programmed to a sufficiently high threshold

voltage. This ensures that all bits have sufficient margin. After the final address is completed,

the entire EPROM memory is read at V

= 5.25

0.25V to verify the entire memory.

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

PROGRAM INHIBIT MODE

Programming of multiple EN27C512 in parallel with different data is also easily accomplished

by using the Program Inhibit Mode. Except for

, all like inputs of the parallel EN27C512

may be common. A TTL low-level program pulse applied to an EN27C512

input with

= 12.75

0.25V will program that EN27C512. A high-level

input inhibits the

other EN27C512 from being programmed.

PROGRAM VERIFY MODE

Verification should be performed on the programmed bits to determining that they were

correctly programmed. The verification should be performed with

and

at V

. Data

should be verified at

after the falling edge of

AUTO PRODUCT IDENTIFICATION

The Auto Product Identification mode allows the reading out of a binary code from an EPROM that

will identify its manufacturer and type. This mode is intended for use by programming equipment

for the purpose of automatically matching the device to be programmed with its corresponding

programming algorithm. This mode is functional in the 25

C ambient temperature range

that is required when programming the EN27C512.

To activate this mode, the programming equipment must force 12.0 V

0.5V on address line A9

of the EN27C512. Two identifier bytes may then be sequenced from the device outputs by

toggling address line A0 from V

to V

, when A1 = V

. All other address lines must be held at

during Auto Product Identification mode.

Byte 0 (A0 = V

) represents the manufacturer code, and byte 1 (A0 = V

), the device code. For

the EN27C512, these two identifiers bytes are given in the Mode Select Table. All identifiers for

manufacturer and device codes will possess odd parity, with the MSB (DQ7) defined as the parity

bit.

When A1 = V

, the EN27C512 will read out the binary code of 7F, continuation code, to

signify the unavailability of manufacturer ID codes.

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

READ MODE

The EN27C512 has two control functions, both of which must be logically satisfied in order to

obtain data at the outputs. Chip Enable (

) is the power control and should be used for

device selection. Output Enable (

) is the output control and should be used to gate data to

the output pins, independent of device selection. Assuming that addresses are stable,

address access time (t

ACC

) is equal to the delay from

to output (t

) . Data is available at

the outputs (t

) after the falling edge of

, assuming the

has been LOW and

addresses have been stable for at least t

ACC

- t

STANDBY MODE

The EN27C512 has CMOS standby mode which reduces the maximum V

current to 20

It is placed in CMOS standby when

is at V

0.3 V. The EN27C512 also has a TTL-

standby mode which reduces the maximum V

current to 1.0 mA. It is placed in TTL-

standby when

is at V

. When in standby mode, the outputs are in a high-impedance

state, independent of the

input.

TWO-LINE OUTPUT CONTROL FUNCTION

To accommodate multiple memory connections, a two-line control function is provided to allow

for:

1. Low memory power dissipation,

2. Assurance that output bus contention will not occur.

It is recommended that

be decoded and used as the primary device-selection function, while

be made a common connection to all devices in the array and connected to the READ line

from the system control bus. This assures 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 memory device.

SYSTEM CONSIDERATIONS

During the switch between active and standby conditions, transient current peaks are produced

on the rising and falling edges of Chip Enable. The magnitude of these transient current peaks

is dependent on the output capacitance loading of the device. At a minimum, a 0.1

F 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 arrays, a 4.7

F bulk electrolytic

capacitor should be used between V

and V

for each eight devices. The location of the

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

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

MODE SELECT TAB

Mode

OE /V

Output

Read

OUT

Output Disable

High Z

Standby (TTL)

High Z

Standby (CMOS)

0.3V

High Z

Program

(4)

Program Verify

OUT

Program Inhibit

p p

High Z

Manufacturer Code

(3)

VH(1)

Device Code

(3)

(1)

NOTES:

1) VH = 12.0V

0.5V

2) X = Either V

or V

3) For Manufacturer Code and Device Code, A1 = V

When A1 = V

, both codes will read 7F

4) See DC Programming Characteristics for V

voltage during programming

EON’S STANDARD PRODUCT IDENTIFICATION CODE

Pins

Hex

Data

Code

DQ7

DQ6

DQ5

DQ4

DQ3

DQ2

DQ1

DQ0

Manufacturer

Device Type

Continuation

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

ABSOLUTE MAXIMUM RATINGS

Storage Temperature

-65

C to +125

Ambient Temperature

with Power Applied

-40

C to +85

Voltage with Respect to V

All pins except A9, V

, V

-0.6V to V

+ 0.5V

A9, V

-0.6V to +13.5V

-0.6V to +7.0V

OPERATING RANGES

Commercial (C)

Case Temperature(Tc)

C to +70

Industrial (I)

Case Temperature(Tc)

-40

C to +85

Supply READ Voltages

+4.50V to +5.5V

(Functionality is guaranteed between these limits)

Stresses above those shown above may cause permanent damage to the device. This is a stress rating only and

operation above these specifications for extended periods may affect device reliability. Operation outside the

"OPERATING RANGES" shown above voids any and all warranty provisions.

DC CHARACTERISTICS FOR READ OPERATION

Symbol

Parameter

Min.

Max.

Unit

Conditions

Output High Voltage

2.4

= -0.4mA

Output Low Voltage

0.45

= 2.1mA

Input High Voltage

2.0

+0.5

Input Low Voltage

-0.3

0.8

Input Leakage Current

-5

= 0 to 5.5V

Output Leakage Current

-10

OUT

= 0 to 5.5V

CC3

Power -Down Current

= V

0.3V

CC2

Standby Current

1.0

= V

CC1

Active Current

= V

, f=5MHz,

OUT

= 0mA

Supply Current Read

100

= OE = V

= 5.5V

CAPACITANCE

Symbol

Parameter

Typ.

Max.

Unit

Conditions

Input Capacitance

= 0V

OUT

Output Capacitance

OUT

= 0V

VPP

Capacitance

= 0V

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

AC CHARACTERISTICS FOR READ OPERATION

EN27C512

-45

-55

-70

-90

Symbol

Parameter

Condition

Min

Max

Min

Max

Min

Max

Min

Max

Unit

tACC (3)

Address to

Output Delay

CE = OE = V

tCE (2)

CE to Output

Delay

OE = V

tOE (2, 3)

OE to Output

Delay

OE = V

tDF (4, 5)

OE or CE High to Output Float,

whichever occurred first

tOH

Output Hold from Address,

CE or OE , whichever occurred

first

FIGURE 6. AC WAVEFORMS FOR READ OPERATION

ADDRESS

ADDRESS VALID

OUTPUT

VALID

tCE

tACC

HIGH Z

tOE

tDF

tOH

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

FIGURE 7. OUTPUT TEST WAVEFORMS AND MEASUREMENTS

DRIVING

LEVELS

MEASUREMENT

LEVEL

3.0V

1.5V

0.0V

tR, tF < 5 ns (10% to 90%)

DRIVING

LEVELS

MEASUREMENT

LEVEL

OUTPUT

Note: CL = 100pF including

jig capacitance, except for the

-45 and -55 devices, where

CL = 30pF.

1.3V

(1N914)

3.3K

2.4V

0.8

2.0

0.45V

tR, tF < 20 ns (10% to 90%)

45 and 55 devices:

Output Test Load

70 and 90 devices:

DC PROGRAMMING CHARACTERISTICS

Test

Limits

Symbol

Parameter

Conditions

Min.

Max

Units

Input Load Current

IN =

, V

5.0

Input Low Level

-0.5

0.8

Input High Level

0.7 V

+ 0.5

Output Low Voltage

OL =

2.1 mA

0.45

Output High Voltage

OH =

-400

2.4

CC2

Supply Current

(Program and Verify)

PP2

Supply Current

CE = PGM = V

IL,

A9 Product Identification Voltage

11.5

12.5

EN27C512

4800 Great America Parkway Ste 202

Tel: 408-235-8680

Santa Clara, CA. 95054

Fax: 408-235-8685

SWITCHING PROGRAMMING CHARACTERISTICS

= + 25

PARAMETER

SYMBOL

STANDARD

PARAMETER DESCRIPTION

Min.

Max

Units

Address Setup Time

OES

OE /V

Setup Time

OEH

OE /V

Hold Time

Data Setup Time

Address Hold Time

Data Hold Time

DFP

Output Enable to Output Float Delay

130

PGM Program Pulse Width

105

VCS

Setup Time

Data Valid from CE

150

OE /V

Hold Time

ORDERING INFORMATION

EN27C512

TEMPERATURE RANGE

(Blank) = Commercial ( 0

C to +70

I = Industrial ( -40

C to +85

PACKAGE

P = 28 Plastic DIP

J = 32 Plastic PLCC

T = 28 Plastic TSOP

SPEED

45 = 45ns

55 = 55ns

70 = 70ns

90 = 90ns

BASE PART NUMBER

EN = EON Silicon Devices

27 = EPROM

C = CMOS

512 = 64K x 8