Rainbow Electronics W24L257 User Manual

Preliminary W24L257

R

32K × 8 CMOS STATIC RAM

GENERAL DESCRIPTION

The W24L257 is a normal-speed, very low-power CMOS static RAM organized as 32768 × 8 bits that
operates on a wide voltage range from 3.0V to 3.6V power supply. This device is manufactured using
Winbond's high performance CMOS technology.

FEATURES

•

Low power consumption:

−

Active: 126 mW (max.)

•

Access time: 70 nS

•

Single 3.3V power supply

•

Fully static operation

•

All inputs and outputs directly TTL compatible

PIN CONFIGURATIONS BLOCK DIAGRAM

VCC

28-pin

TSOP

28

27

WE

26

A13

25

A8

A9

24

A11

23

OE

22

A10

21

20

CS

I/O 8

19

I/O 7

18

I/O 6

17

16

I/O 5

15

I/O 4

28

A10

27

CS

26

I/O8

25

I/O7

24

I/O6

23

I/O5

22

I/O4

21

V

SS

20

I/O3

19

I/O2

18

I/O1

17

A0

16

A1

15

A2

1

A14

2

A12

3

A7

A6

4

A5

5

A4

6

A3

7

A2

8

A1

9

A0

10

11

I/O 1

12

I/O 2

13

I/O 3

V

SS

14

OE

A11

2

A9

3

A8

4

A13

5

WE

6

V

DD

7

A14

8

A12

9

A7

10

A6

11
12

A5

13

A4

14

A3

•

Three-state outputs

•

Battery back-up operation capability

•

Data retention voltage: 2V (min.)

•

Packaged in 450 mil SOP, standard type one
TSOP (8 mm × 20 mm) ,

CLK GEN. PRECHARGE CKT.

A12

A14

A2

A3

A4

A5

A6

A7

A13

I/O1

I/O8

WE

CS

OE

R
O

CORE CELL ARRAY

W

512 ROWS

D
E

32 X 8 COLUMNS

C
O
D
E

DATA

:

CNTRL

CLK
GEN.

I/O CKT.

COLUMN DECODER

A10

A11

A8A1A0

A9

PIN DESCRIPTION

SYMBOL DESCRIPTION

A0−A14

I/O1−I/O8

CS

WE

OE

VDD Power Supply
VSS Ground

NC No Connection

Address Inputs
Data Inputs/Outputs
Chip Select Input

Write Enable Input

Output Enable Input

Publication Release Date: May 2000

- 1 - Revision A1

Preliminary W24L257

OE WE

TRUTH TABLE

V

CS

MODE

I/O1

−

I/O8

H X X Not Selected High Z ISB, I

L H H Output Disable High Z IDD

L L H Read Data Out IDD

L X L Write Data In IDD

DC CHARACTERISTICS

Absolute Maximum Ratings

PARAMETER RATING UNIT

Supply Voltage to VSS Potential -0.5 to +4.6 V

Input/Output to V

Allowable Power Dissipation 1.0 W

Storage Temperature -65 to +150

Operating Temperature LL 0 to 70

LE -20 to 85

Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability

of the device.

SS

Potential -0.5 to VDD +0.5 V

DD CURRENT

SB1

°

C

°

C

Operating Characteristics

(VDD = 3.0V to 3.6V; VSS = 0V; TA (°C) = 0 to 70 for LL, -20 to 85 for LE)

PARAMETER SYM. TEST CONDITIONS MIN. MAX. UNIT

I

IL

IH

LI

LO

OL

OH

DD

- -0.5 +0.6 V

- +2.0 VDD +0.5 V

VIN = VSS to VDD -1 +1

VI/O = VSS to VDD,

CS

OE = V

WE

IH

(min.) or

= V

IH

(min.) or

= VIL (max.)

-1

IOL = +2.1 mA - 0.4 V

IOH = -1.0 mA 2.2 - V

CS

= VIL (max.) and

I/O = 0 mA,

-

Cycle = min. Duty = 100%

- 2 -

Input Low Voltage V

Input High Voltage V

Input Leakage Current I

Output Leakage Current I

Output Low Voltage V

Output High Voltage V

Operating Power Supply
Current

+1

35

µ

A

µ

A

mA

Preliminary W24L257

Operating Characteristics, continued

PARAMETER SYM. TEST CONDITIONS MIN. MAX. UNIT

Standby Power Supply
Current

I

Note: Typical parameter is measured under ambient temperature TA = 25° C and VDD = 3.3V

CAPACITANCE

(VDD = 3.3V, TA = 25° C, f = 1 MHz)

PARAMETER SYM. CONDITIONS MAX. UNIT

Input Capacitance CIN V

Input/Output Capacitance C

Note: These parameters are sampled but not 100% tested.

AC Characteristics

AC Test Conditions

Input Pulse Levels 0V to 3.0V

Input Rise and Fall Times 5 nS

Input and Output Timing Reference Level 1.5V

Output Load See the drawing below

PARAMETER CONDITIONS

SB

I

CS

= V

IH

(min.) or

Cycle = min. Duty = 100%

SB1

CS

≥ VDD -0.2V

I/O

V

IN

= 0V 6 pF

OUT

= 0V 8 pF

-

1

- 15 µ

mA

A

AC Test Loads and Waveform

OUTPUT

1 TTL

100 pF
Including
Jig and
Scope

3.0 V

0 V

5 nS

OUTPUT

(For T T T T T T )

CLZ, OLZ,

90%

10%

CHZ,

90%

10%

5 nS

1 TTL

5 pF
Including
Jig and
Scope

OHZ, WHZ, OW

Publication Release Date: May 2000

- 3 - Revision A1