Preliminary W24256A
32K × 8 HIGH SPEED CMOS STATIC RAM
Publication Release Date: October 1999
- 1 - Revision A1
GENERAL DESCRIPTION
The W24256A is a high speed, low power CMOS static RAM organized as 32768 × 8 bits that
operates on a single 5-volt power supply. This device is manufactured using Winbond's high
performance CMOS technology.
FEATURES
• High speed access time: 15/35 nS (max.)
• Low power consumption:
− Active: 550 mW (max.)
• Single +5V power supply
• Fully static operation
• All inputs and outputs directly TTL compatible
• Three-state outputs
• Available packages: 28-pin 300 mil SOJ, 330
mil SOP, skinny DIP and standard type one
TSOP (8 mm × 13.4 mm)
PIN CONFIGURATIONS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28-pin
DIP
28
27
26
25
24
23
22
21
20
19
18
17
16
15
VDD
WE
A13
A8
A9
A11
OE
A10
CS
I/O8
I/O7
I/O6
I/O5
I/O4
A14
A12
A7
A6
A5
A4
A3
A2
A1
A0
I/O1
I/O2
I/O3
VSS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
28
27
26
25
24
23
22
21
20
19
18
17
16
15
28-pin
TSOP
OE
A11
A9
A8
A13
WE
VDD
A14
A12
A7
A6
A5
A4
A3
A10
CS
I/O8
I/O7
I/O6
I/O5
I/O4
I/O3
I/O2
I/O1
A0
A1
A2
VSS
BLOCK DIAGRAM
A0
.
.
CS
A14
WE
I/O1
I/O8
OE
VDD
VSS
.
.
DATA I/O
DECODER
CONTROL
CORE
ARRAY
PIN DESCRIPTION
SYMBOL DESCRIPTION
A0−A14 Address Inputs
I/O1−I/O8 Data Inputs/Outputs
CS
Chip Select Input
WE
Write Enable Input
OE
Output Enable Input
VDD Power Supply
VSS Ground
Preliminary W24256A
- 2 -
DC CHARACTERISTICS
Absolute Maximum Ratings
PARAMETER RATING UNIT
Supply Voltage to VSS Potential -0.5 to +7.0 V
Input/Output to VSS Potential -0.5 to VDD +0.5 V
Allowable Power Dissipation 1.0 W
Storage Temperature -65 to +150 °C
Operating Temperature 0 to +70 °C
Note: Exposure to conditions beyond those listed under Absolute Maximum Ratings may adversely affect the life and reliability
of the device.
TRUTH TABLE
CS
OE
WE
MODE I/O1
−
I/O8 VDD CURRENT
H X X Not Selected High Z ISB, ISB1
L H H Output Disable High Z IDD
L L H Read Data Out IDD
L X L Write Data In IDD
OPERATING CHARACTERISTICS
(VDD = 5V ±10%, VSS = 0V, TA = 0 to 70° C)
PARAMETER SYM.
TEST CONDITIONS MIN.
TYP.
MAX. UNIT
Input Low Voltage VIL - -0.5 - +0.8 V
Input High Voltage VIH - +2.2 - VDD +0.5 V
Input Leakage Current ILI VIN = VSS to VDD -5 - +5 µA
Output Leakage
Current ILO VI/O = VSS to VDD,
CS
= VIH
or
OE
= VIH or
WE
= VIL -5 - +5 µA
Output Low Voltage VOL IOL = +8.0 mA - - 0.4 V
Output High Voltage VOH IOH = -4.0 mA 2.4 - - V
Operating Power
Supply Current IDD
= VIL, I/O = 0 mA
Cycle = min , Duty = 100%
- - 110 mA
Standby Power
Supply Current
ISB
= VIH
Cycle = MIN., Duty = 100% - - 25 mA
ISB1
≥ VDD -0.2V - - 1 mA
Note: Typical characteristics are at VDD = 5V, TA = 25° C.
Preliminary W24256A
Publication Release Date: October 1999
- 3 - Revision A1
CAPACITANCE
(VDD = 5V, TA = 25° C, f = 1 MHz)
PARAMETER SYM. CONDITIONS MAX. UNIT
Input Capacitance CIN VIN = 0V 8 pF
Input/Output Capacitance CI/O VOUT = 0V 10 pF
Note: These parameters are sampled but not 100% tested.
AC TEST CONDITIONS
PARAMETER CONDITIONS
Input Pulse Levels 0V to 3V
Input Rise and Fall Times 5 nS
Input and Output Timing Reference Level 1.5V
Output Load CL = 30 pF, IOH/IOL = -4 mA/8 mA
AC TEST LOADS AND WAVEFORM
90% 90%
5 nS
10%
5 nS 10%
R1 480 ohm
5V
OUTPUT
R2
255 ohm
5 pF R2
255 ohm
R1 480 ohm
5V
OUTPUT
30 pF
Including
Jig and
Scope
3.0V
0V
Including
Jig and
Scope
)
(For TCLZ,, , ,,
TOLZ TCHZ TOHZ TWHZ TOW
Preliminary W24256A
- 4 -
AC CHARACTERISTICS
(VDD = 5V ±10%, VSS = 0V, TA = 0 to 70° C)
Read Cycle
PARAMETER SYM. W24256A-15 W24256A-35 UNIT
MIN. MAX. MIN. MAX.
Read Cycle Time TRC 15 - 35 - nS
Address Access Time TAA - 15 - 35 nS
Chip Select Access Time TACS - 15 - 35 nS
Output Enable to Output Valid TAOE - 7 - 12 nS
Chip Selection to Output in Low Z TCLZ∗ 3 - 3 - nS
Output Enable to Output in Low Z TOLZ∗ 0 - 0 - nS
Chip Deselection to Output in High
Z TCHZ∗ - 4 - 7 nS
Output Disable to Output in High Z TOHZ∗ - 4 - 7 nS
Output Hold from Address Change TOH 3 - 3 - nS
∗ These parameters are sampled but not 100% tested.
Write Cycle
PARAMETER SYM. W24256A-15 W24256A-35 UNIT
MIN. MAX. MIN. MAX.
Write Cycle Time TWC 15 - 35 - nS
Chip Selection to End of Write TCW 12 - 20 - nS
Address Valid to End of Write TAW 12 - 20 - nS
Address Setup Time TAS 0 - 0 - nS
Write Pulse Width TWP 11 - 15 - nS
Write Recovery Time CS , WE TWR 1.5 - 1.5 - nS
Data Valid to End of Write TDW 8 - 10 - nS
Data Hold from End of Write TDH 0 - 0 - nS
Write to Output in High Z TWHZ∗ - 5 - 5 nS
Output Disable to Output in High Z TOHZ∗ - 5 - 5 nS
Output Active from End of Write TOW 3 - 3 - nS
∗ These parameters are sampled but not 100% tested.
Preliminary W24256A
Publication Release Date: October 1999
- 5 - Revision A1
TIMING WAVEFORMS
Read Cycle 1
(Address Controlled)
Address
TRC
T
AA
TOH TOH
DOUT
Read Cycle 2
(Chip Select Controlled)
CS
DOUT TCLZ
TACS CHZ
T
Read Cycle 3
(Output Enable Controlled)
Address
TRC
CS
DOUT
TAA
OE
TAOE
TOLZ
TOH
CLZ
TCHZ
T
TACS TOHZ
Preliminary W24256A
- 6 -
Timing Waveforms, continued
Write Cycle 1
(
OE
Clock)
Address
OE
CS
WE
DOUT
DIN
TWC
TWR
TCW
TWP
TAS
TOHZ (1, 4)
TDW TDH
TAW
Write Cycle 2
(
OE
= VIL Fixed)
Address
CS
WE
DOUT
IN
TWC
CW
TAS
DH
TWR
WP
TWHZ
DW
(2) (3)
OW
TOH
AW
(1, 4)
Notes:
1. During this period, I/O pins are in the output state, so input signals of opposite phase to the outputs should not be applied.
2. The data output from DOUT are the same as the data written to DIN during the write cycle.
3. DOUT provides the read data for the next address.
4. Transition is measured ±500 mV from steady state with CL = 5 pF. This parameter is guaranteed but not 100% tested.
Preliminary W24256A
Publication Release Date: October 1999
- 7 - Revision A1
ORDERING INFORMATION
PART NO. ACCESS
TIME
(nS)
OPERATING
CURRENT
MAX. (mA)
STANDBY
CURRENT
MAX. (mA)
PACKAGE
W24256AK-15 15 110 1 300 mil skinny DIP
W24256AK-35 35 110 1 300 mil skinny DIP
W24256AJ-15 15 110 1 300 mil SOJ
W24256AJ-35 35 110 1 300 mil SOJ
W24256AS-15 15 110 1 330 mil SOP
W24256AS-35 35 110 1 330 mil SOP
W24256AQ-15 15 110 1 Standard type one TSOP
W24256AQ-35 35 110 1 Standard type one TSOP
Notes:
1. Winbond reserves the right to make changes to its products without prior notice.
2. Purchasers are responsible for performing appropriate quality assurance testing on products intended for use in
applications where personal injury might occur as a consequence of product failure.
Preliminary W24256A
- 8 -
PACKAGE DIMENSIONS
28-pin P-DIP Skinny
1. Dimensions D Max. & S include mold flash or
tie bar burrs.
2. Dimension E1 does not include interlead flash.
3. Dimensions D & E1 include mold mismatch and
are determined at the mold parting line.
6. General appearance spec. should be based on
final visual inspection spec.
1.631.470.0640.058
Notes:
Symbol Min. Nom. Max. Max.Nom.Min.
Dimension in Inches Dimension in mm
0.060 1.52
0.175 4.45
0.010
0.125
0.016
0.130
0.018
0.135
0.022
3.18
0.41
0.25
3.30
0.46
3.43
0.56
0.008
0.120
0.370
0.010
0.130
0.014
0.140
0.20
3.05
0.25
3.30
0.36
3.56
0.293
0.2880.283 7.447.32
7.19
9.40
7.877.62 8.13
0.3100.300 0.320
2.29 2.54 2.790.090 0.100 0.110
A
B
c
D
e
A
L
S
A
A1
2
E
B1
1
e
E1
a
1.388 1.400 35.26 35.56
0°15°
0.055 1.40
0.350
0.330 8.38 8.89
15°
0°
4. Dimension B1 does not include dambar
protrusion/intrusion.
5. Controlling dimension: Inches.
eA
A
a
c
E
Base Plane
Mounting Plane
1
A
1
e
L
A
S
1E
D
1
B
B
28 15
1 14
2
28-pin Small Outline J Band
1
y
1
e
s1
b
b
c
L
e
Seating Plane
1
2
A
AA
D
E
HE
14
15
28
£c
0.360.20
0.014
0.008
Symbol Min. Nom. Max. Max.Nom.
Min.
Dimension in Inches Dimension in mm
A
b
c
D
e
HE
L
y
θ
A
A
S
1
1
2
E
0.010 0.25
0.140 3.56
0.027
0.095
0.016
0.100
0.018
0.105
0.022
2.41
0.41
0.69
2.54
0.46
2.67
0.56
0.077
0.004
010
0.710
0.087
0.730
0.097 1.96
18.03
2.21
18.54
2.46
0.285
0.2650.245 7.246.736.22
0
0.10
7.75
7.62
7.49
0.3050.300
0.295
8.31 8.56 8.810.327 0.337 0.347
1. Dimensions D Max. & S include mold flash
or tie bar burrs.
2. Dimension b does not include dambar
protrusion/intrusion.
4. Controlling dimension: Inches.
5. General appearance spec. should be based
on final visual inspection spec.
Notes:
3. Dimensions D & E include mold mismatch
and are determined at the mold parting line.
e
b10.810.710.66
0.0320.028
0.026
0.044 0.050 0.056 1.12 1.27 1.42
0.045 1.14
10
Preliminary W24256A
Publication Release Date: October 1999
- 9 - Revision A1
Package Dimensions, continued
28-pin SO Wide Body
2
1
A
28 15
14
1
e
S
EH
b
Seating Plane
AA
yL
L
e
c
See Detail F
D
E
E
1
1
e
Detail F
1. Dimensions D Max. & S include mold flash
or tie bar burrs.
2. Dimension b does not include dambar
protrusion/intrusion.
3. Dimensions D & E include mold mismatch
and are determined at the mold parting line.
.
0.250.20
0.0100.008
Notes:
Symbol Min. Nom. Max. Max.
Nom.
Min.
Dimension in Inches Dimension in mm
A
b
c
D
e
HE
L
y
A
A
LE
1
2
E
0.014 0.36
0.112 2.85
0.004
0.093
0.014
0.098
0.016
0.103
0.020
2.36
0.36
0.10
2.49
0.41
2.62
0.51
0.059
0.004
010
0.713
0.067
0.733
0.075 1.50
18.11
1.70
18.62
1.91
0.4770.4650.453 12.1211.8111.51
10
0
0.10
8.53
8.41
8.28
0.3360.3310.326
0.71 0.91 1.120.028 0.036 0.044
4. Controlling dimension: Inches.
5. General appearance spec should be based
on final visual inspection spec.
1.12 1.27 1.420.044 0.050 0.056
S1.190.047
θ
θ
28-pin Standard Type One TSOP
Note: Controlling dimension: Millimeters
A
A
A2
1
L
L1
Y
c
E
H
D
D
b
e
Min.
Dimension in Inches
Nom. Max. Min. Nom. Max.
Symbol
1.20
0.05 0.15
1.05
1.000.95
0.17
0.10
11.70
7.90
13.20
0.50
0.00
0
0.20 0.27
0.15 0.21
11.80 11.90
8.00 8.10
13.40 13.60
0.55
0.60 0.70
0.25
0.10
35
0.047
0.006
0.041
0.040
0.035
0.007 0.008 0.011
0.004 0.006 0.008
0.461 0.465 0.469
0.311 0.315 0.319
0.520 0.528 0.536
0.022
0.020 0.024 0.028
0.010
0.000 0.004
0 3 5
0.002
A
A
b
c
D
E
e
L
L
Y
1
1
2
A
HD
θ
Dimension in mm
θ
Preliminary W24256A
- 10 -
VERSION HISTORY
VERSION DATE PAGE DESCRIPTION
A1 Oct. 1999 Initial Issued
Headquarters
No. 4, Creation Rd. III,
Science-Based Industrial Park,
Hsinchu, Taiwan
TEL: 886-3-5770066
FAX: 886-3-5796096
http://www.winbond.com.tw/
Voice & Fax-on-demand: 886-2-27197006
Taipei Office
11F, No. 115, Sec. 3, Min-Sheng East Rd.,
Taipei, Taiwan
TEL: 886-2-27190505
FAX: 886-2-27197502
Winbond Electronics (H.K.) Ltd.
Rm. 803, World Trade Square, Tower II,
123 Hoi Bun Rd., Kwun Tong,
Kowloon, Hong Kong
TEL: 852-27513100
FAX: 852-27552064
Winbond Electronics North America Corp.
Winbond Memory Lab.
Winbond Microelectronics Corp.
Winbond Systems Lab.
2727 N. First Street, San Jose,
CA 95134, U.S.A.
TEL: 408-9436666
FAX: 408-5441798
Note: All data and specifications are subject to change without notice.