WS27C256L-15DMB - STMicroelectronics

PRODUCT SELECTION GUIDE

PARAMETER WS27C256L-12 WS27C256L-15 WS27C256L-20

Address Access Time (Max) 120 ns 150 ns 200 ns

Chip Select Time (Max) 120 ns 150 ns 200 ns

Output Enable Time (Max) 35 ns 40 ns 40 ns

WS27C256L

TOP VIEW

Chip Carrier CERDIP

PIN CONFIGURATION

4-19

Military 32K x 8 CMOS EPROM

KEY FEATURES

•High Performance CMOS •Ceramic Leadless Chip Carrier (CLLCC)

— 120 ns Access Time •EPI Processing

•Fast Programming — Latch-Up Immunity to 200 mA

•DESC SMD No. 5962-86063 — ESD Protection Exceeds 2000 Volts

•300 Mil DIP or Standard 600 Mil DIP •JEDEC Standard Pin Configuration

GENERAL DESCRIPTION

The WS27C256L is a performance oriented 256K UV Erasable Electrically Programmable Read Only Memory

organized as 32K words x 8 bits/word. It is manufactured using an advanced CMOS technology which enables it to

operate at speeds up to 120 nsecs. The memory was designed utilizing WSI's patented self-aligned split gate

EPROM cell, resulting in a low power device with a very cost effective die size.

The WS27C256L 256K EPROM provides 32K of 8 bit wide code store capacity for DSP, microprocessor, and

microcontroller-based systems. Its 120 nsec access time over the full Military temperature range provides the

potential of no-wait state operation. And where this parameter is important, the WS27C256L provides the user with

a very fast 35 nsec TOE output enable time.

The WS27C256L is offered in a 28 pin 300 mil skinny CERDIP or the standard 600 mil CERDIP, and also in a

32 pad Ceramic Leadless Chip Carrier (CLLCC) for surface mount applications. All packages incorporate the

standard JEDEC EPROM pinout.

A11

A10

CE/PGM

A12

VPP

VCC

A14

A13

O1 O2 NC O3 O4 O5

432 32 31 30

14 15 16 17 18 19 20

GND

VCC

A14

A13

A11

A10

CE/PGM

VPP

A12

GND

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AC READ CHARACTERISTICS

Over Operating Range (See Above)

SYMBOL PARAMETER WS27C256L-12 WS27C256L-15 WS27C256L-20 UNITS

MIN MAX MIN MAX MIN MAX

tACC Address to Output Delay 120 150 200

tCE CE to Output Delay 120 150 200

tOE OE to Output Delay 35 40 40

tDF Output Disable to Output Float 35 40 40 ns

(Note 3)

Output Hold From Addresses,

tOH CE or OE, Whichever Occurred 0 0 0

First (Note 3)

DC READ CHARACTERISTICS

Over Operating Range. (See Above)

SYMBOL PARAMETER TEST CONDITIONS MIN MAX UNITS

VIL Input Low Voltage –0.5 0.8 V

VIH Input High Voltage 2.0 VCC + 1 V

VOL Output Low Voltage IOL = 2.1 mA 0.4 V

VOH Output High Voltage IOH = –400 µA 3.5 V

ISB1 VCC Standby Current (CMOS) CE = VCC ± 0.3 V (Note 2) 100 µA

ISB2 VCC Standby Current CE = VIH 1mA

CC VCC Active Current CE = OE = VIL F = 5 MHz 40 mA

(Note 1) F = 8 MHz 50 mA

IPP VPP Supply Current VPP = VCC 100 µA

VPP VPP Read Voltage VCC –0.4 VCC V

ILI Input Leakage Current VIN = 5.5 V or Gnd –10 10 µA

ILO Output Leakage Current VOUT = 5.5 V or Gnd –10 10 µA

WS27C256L

4-20

OPERATING RANGE

RANGE TEMPERATURE VCC

Military –55°C to +125°C +5V ± 10%

ABSOLUTE MAXIMUM RATINGS*

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

Voltage on any Pin with

Respect to Ground ....................................–0.6V to +7V

VPP with Respect to Ground...................–0.6V to + 14V

VCC Supply Voltage with

Respect to Ground ....................................–0.6V to +7V

ESD Protection..................................................>2000V

NOTES: 1. The supply current is the sum of ICC and IPP. The maximum current value is with Outputs O0to O7unloaded.

2. CMOS inputs: VIL = GND ± 0.3V, VIH = VCC ± 0.3 V.

*NOTICE:

Stresses above those listed under "Absolute Maximum

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 conditions above

those indicated in the operational sections of this

specification is not implied. Exposure to absolute

maximum rating conditions for extended periods of

time may affect device reliability.

NOTE: 3.

This parameter is only sampled and is not 100% tested. Output Float is defined as the point where data is no longer driven – see timing

diagram.

SYMBOL PARAMETER CONDITIONS TYP(6) MAX UNITS

CIN Input Capacitance VIN = 0V 4 6 pF

COUT Output Capacitance VOUT = 0V 8 12 pF

CVPP VPP Capacitance VPP = 0 V 18 25 pF

4-21

WS27C256L

AC READ TIMING DIAGRAM

tACC tOH

ADDRESS VALID

VALID OUTPUT

ADDRESSES VIH

VIL

tOE

tDF

tCE

VIH

VIL

VIH

VIL

HIGH ZHIGH Z

(5)

(4)

OUTPUT

CAPACITANCE

(5)

TA= 25°C, f = 1 MHz

100 pF

(INCLUDING SCOPE

AND JIG

CAPACITANCE)

820 Ω

2.01 V

D.U.T.

A.C. TESTING INPUT/OUTPUT WAVEFORMTEST LOAD

(High Impedance Test Systems)

2.4

0.4

2.0

0.8

2.0

0.8

TEST

POINTS

NOTES: 5. This parameter is only sampled and is not 100% tested.

6. Typical values are for TA= 25°C and nominal supply voltages.

A.C. testing inputs are driven at 2.4 V for a logic "1" and 0.4 V

for a logic "0." Timing measurements are made at 2.0 V for a

logic "1" and 0.8 V for a logic "0".

NOTE: 4. OE may be delayed up to tCE – tOE after the falling edge of CE without impact on tCE.

NOTE: 7. Provide adequate decoupling capacitance as close as possible to this device to achieve the published A.C. and D.C. parameters.

A 0.1 microfarad capacitor in parallel with a 0.01 microfarad capacitor connected between VCC and ground is recommended.

Inadequate decoupling may result in access time degradation or other transient performance failures.

PROGRAMMING INFORMATION

DC CHARACTERISTICS

(TA= 25 ± 5°C, VCC = 6.0 ± 0.25 V, VPP = 12.5 ± 0.5 V. See Notes 8, 9 and 10)

SYMBOLS PARAMETER MIN MAX UNITS

ILI Input Leakage Current (VIN = VCC or Gnd) –10 10 µA

IPP VPP Supply Current During 60 mA

Programming Pulse (CE/PGM = VIL)

ICC VCC Supply Current 40 mA

VIL Input Low Voltage –0.1 0.8 V

VIH Input High Voltage 2.0 VCC + 0.3 V

VOL Output Low Voltage During Verify (IOL = 2.1 mA) 0.4 V

VOH Output High Voltage During Verify (IOH = –400 µA) 3.5 V

SYMBOLS PARAMETER MIN TYP MAX UNITS

tAS Address Setup Time 2 µs

tCOH CE High to OE High 2 µs

tOES Output Enable Setup Time 2 µs

tOS Data Setup Time 2 µs

tAH Address Hold Time 0 µs

tOH Data Hold Time 2 µs

tDF Chip Disable to Output Float Delay 0 55 ns

tOE Data Valid From Output Enable 55 ns

tVS VPP Setup Time 2 µs

tPW PGM Pulse Width 500 1000 µs

tOCX OE Low to CE "Don't Care" 2 µs

WS27C256L

4-22

NOTES: 8. VCC must be applied either coincidentally or before VPP and removed either coincidentally or after VPP.

9. VPP must not be greater than 14 volts including overshoot. During CE/PGM = VIL, VPP must not be switched from 5 volts

to 12.5 volts or vice-versa.

10. During power up the CE/PGM pin must be brought high (≥VIH) either coincident with or before power is applied to VPP.

AC CHARACTERISTICS

(TA= 25 ± 5°C, VCC = 6.0 ± 0.25 V, VPP = 12.5 ± 0.5 V)

PROGRAMMING WAVEFORM

ADDRESS STABLE

ADDRESSES

VPP

VPP VCC

CE/PGM

DATA

tAS

tPW

tOS tOH tOE

tAH

tDF

tVS

tCES

tOES

tOCX tCOH

DATA OUT

DATA IN STABLE

VIH

VIL

VIH

VIL

VALID

HIGH Z

ORDERING INFORMATION

OPERATING WSI

PART NUMBER TEMPERATURE MANUFACTURING

RANGE PROCEDURE

WS27C256L-12CMB*120 32 Pad CLLCC C2 Military MIL-STD-883C

WS27C256L-12DMB*120 28 Pin CERDIP, 0.6" D2 Military MIL-STD-883C

WS27C256L-12TMB*120 28 Pin CERDIP, 0.3" T2 Military MIL-STD-883C

WS27C256L-15DMB*150 28 Pin CERDIP, 0.6" D2 Military MIL-STD-883C

WS27C256L-15TMB*150 28 Pin CERDIP, 0.3" T2 Military MIL-STD-883C

WS27C256L-20DMB*200 28 Pin CERDIP, 0.6" D2 Military MIL-STD-883C

4-23

WS27C256L

NOTE: The actual part marking will not include the initials "WS."

*SMD product. See page 4-1 for SMD number.

PROGRAMMING/ALGORITHMS/ERASURE/PROGRAMMERS REFER TO

PAGE 5-1

The WS27C256L is programmed using Algorithm C shown on page 5-7.

SPEED PACKAGE PACKAGE

(ns) TYPE DRAWING

MODE PINS CE/PGM OE A9A0VPP VCC OUTPUTS

Read VIL VIL XXV

CC 5.0 V DOUT

Output Disable X VIH XXV

CC 5.0 V High Z

Standby VIH XXXV

CC 5.0 V High Z

Programming VIL VIH XXV

PP(12) 5.8 V DIN

Program Verify X VIL XXV

PP(12) 5.8 V DOUT

Program Inhibit VIH VIH XXV

PP(12) 5.0 V High Z

Signature Manufacturer(13) VIL VIL VH(12) VIL VCC 5.0 V 23 H

Device(13) VIL VIL VH(12) VIH VCC 5.0 V C0 H

MODE SELECTION

The modes of operation of the WS27C256L are listed below. A single 5 V power supply is required in the read

mode. All inputs are TTL levels except for VPP and A9for device signature.

NOTES: 11. X can be VIL or VIH.

12. VH= VPP = 12.5 ± 0.5 V.

13. A1– A8, A10 – A14 = VIL.

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