PHILIPS 74F256

INTEGRATED CIRCUITS
74F256
Dual addressable latch
Product specification
IC15 Data Handbook
1988 Nov 29
Philips Semiconductors
Product specification
Dual addressable latch
74F256
FEATURES
PIN CONFIGURATION
• Combines dual demultiplexer and 8-bit latch
• Serial-to-parallel capability
• Output from each storage bit available
• Random (addressable) data entry
• Easily expandable
• Common reset input
• Useful as dual 1-of-4 active High decoder
A0 1
16 V
CC
A1 2
15 MR
Da 3
14 E
Q0a 4
13 Db
Q1a 5
12 Q3b
Q2a 6
11 Q2b
Q3a 7
10 Q1b
8
9 Q0b
GND
DESCRIPTION
SF00805
The 74F256 dual addressable latch has four distinct modes of
operation which are selectable by controlling the Master Reset (MR)
and Enable (E) inputs (see Function Table). In the addressable latch
mode, data at the Data inputs is written into the addressed latches.
The addressed latches will follow the Data input with all
unaddressed latches remaining in their previous states. In the
memory mode, all latches remain in their previous states and are
unaffected by the Data or Address inputs. To eliminate the possibility
of entering erroneous data in the latches, the enable should be held
High (inactive) while the address lines are changing. In the dual
1-of-4 decoding or demultiplexing mode (MR=E=Low), addressed
outputs will follow the level of the Data inputs, with all other outputs
Low. In the Master Reset mode, all outputs are Low and unaffected
by the Address and Data inputs.
TYPE
TYPICAL
PROPAGATION
DELAY
TYPICAL SUPPLY
CURRENT (TOTAL)
7.0ns
28mA
74F256
ORDERING INFORMATION
ORDER CODE
DESCRIPTION
COMMERCIAL RANGE
VCC = 5V ±10%,
Tamb = 0°C to +70°C
PKG DWG #
16-pin plastic DIP
N74F256N
SOT38-4
16-pin plastic SO
N74F256D
SOT109-1
INPUT AND OUTPUT LOADING AND FAN OUT TABLE
PINS
DESCRIPTION
74F (U.L.)
HIGH/LOW
LOAD VALUE
HIGH/LOW
Da, Db
Port A, port B inputs
1.0/1.0
20µA/0.6mA
A0, A1
Address inputs
1.0/1.0
20µA/0.6mA
Enable (active Low)
1.0/1.0
20µA/0.6mA
Master Reset inputs (active Low)
1.0/1.0
20µA/0.6mA
Port A outputs
50/33
1.0mA/20mA
50/33
1.0mA/20mA
E
MR
Q0a – Q3a
Q0b – Q3b
Port B outputs
NOTE:
One (1.0) FAST unit load is defined as: 20µA in the High state and 0.6mA in the Low state.
1988 Nov 29
2
853–0359 95207
Philips Semiconductors
Product specification
Dual addressable latch
74F256
LOGIC SYMBOL
IEC/IEEE SYMBOL
3
Z5
13
3
13
Da
14
E
1
A0
2
A1
15
MR
Z6
15
G4
5, 7D
Db
1
0
1
0
G
Q0a Q1a Q2a Q3a
2
Q0b Q1b Q2b Q3b
1
0
3
1
5
2
6
3
7
14
4
5
6
7
9
10
11
4
C7
4R
6, 8D
12
1
0
9
C8
4R
10
1
11
2
12
3
VCC = Pin 16
GND = Pin 8
SF00806
SF00807
FUNCTION TABLE
INPUTS
H
L
X
d
q
OUTPUTS
MR
E
D
A0
A1
Q0
Q1
Q2
Q3
L
H
X
X
L
L
d
L
X
L
L
L
L
L
Q=d
L
L
L
L
L
d
H
L
L
Q=d
L
L
L
L
L
L
d
L
H
L
L
Q=d
L
d
H
H
L
L
L
Q=d
H
H
H
X
X
X
q0
q1
q2
q3
L
d
L
L
Q=d
q1
q2
q3
H
L
d
H
L
q0
Q=d
q2
q3
H
L
d
L
H
q0
q1
Q=d
q3
OPERATING MODE
Master Reset
Demultiplex (active-High decoder when D=H)
Store (do nothing)
Addressable Latch
H
L
d
H
H
q0
q1
q2
Q=d
= High voltage level
= Low voltage level
= Don’t care
= High or Low data one setup time prior to the Low-to-High Enable transition
= Lower case letters indicate the state of the referenced output established during the last cycle in which it was addressed or cleared.
1988 Nov 29
3
Philips Semiconductors
Product specification
Dual addressable latch
74F256
LOGIC DIAGRAM
12
Q3b
11
Q2b
10
Q1b
9
Q0b
7
Q3a
6
Db
13
Da
3
E
14
MR
15
5
A1
A0
Q2a
Q1a
2
1
4
Q0a
VCC = Pin 16
GND = Pin 8
SF00808
1988 Nov 29
4
Philips Semiconductors
Product specification
Dual addressable latch
74F256
ABSOLUTE MAXIMUM RATINGS
(Operation beyond the limit set forth in this table may impair the useful life of the device.
Unless otherwise noted these limits are over the operating free air temperature range.)
SYMBOL
PARAMETER
RATING
UNIT
V
VCC
Supply voltage
–0.5 to +7.0
VIN
Input voltage
–0.5 to +7.0
V
IIN
Input current
–30 to +5
mA
VOUT
Voltage applied to output in High output state
–0.5 to VCC
V
IOUT
Current applied to output in Low output state
40
mA
Tamb
Operating free-air temperature range
0 to +70
°C
Tstg
Storage temperature range
–65 to +150
°C
RECOMMENDED OPERATING CONDITIONS
PARAMETER
SYMBOL
LIMITS
UNIT
MIN
NOM
MAX
5.0
5.5
VCC
Supply voltage
4.5
VIH
High-level input voltage
2.0
VIL
Low-level input voltage
0.8
V
IIK
Input clamp current
–18
mA
IOH
High-level output current
–1
mA
IOL
Low-level output current
20
mA
70
°C
Tamb
Operating free-air temperature range
V
V
0
DC ELECTRICAL CHARACTERISTICS
(Over recommended operating free-air temperature range unless otherwise noted.)
PARAMETER
SYMBOL
TEST
LIMITS
CONDITIONS1
MIN
±10%VCC
2.5
VIH = MIN, IOL = MAX
±5%VCC
2.7
VCC = MIN, VIL = MAX,
±10%VCC
VIH = MIN, IOL = MAX
±5%VCC
VOH
High-level output voltage
VCC = MIN, VIL = MAX,
VOL
Low-level output voltage
VIK
Input clamp voltage
VCC = MIN, II = IIK
TYP2
UNIT
MAX
V
3.4
V
0.35
0.50
V
0.35
0.50
V
–0.73
-1.2
V
II
Input current at maximum input voltage
VCC = MAX, VI = 7.0V
100
µA
IIH
High-level input current
VCC = MAX, VI = 2.7V
20
µA
IIL
Low-level input current
VCC = MAX, VI = 0.5V
–0.6
mA
IOS
Short-circuit output current3
VCC = MAX
–150
mA
ICC
Supply current (total)
21
42
mA
33
60
ICCH
VCC = MAX
ICCL
–60
mA
NOTES:
1. For conditions shown as MIN or MAX, use the appropriate value specified under recommended operating conditions for the applicable type.
2. All typical values are at VCC = 5V, Tamb = 25°C.
3. To reduce the effect of external noise during test.
4. Not more than one output should be shorted at a time. For testing IOS, the use of High-speed test apparatus and/or sample-and-hold
techniques are preferable in order to minimize internal heating and more accurately reflect operational values. Otherwise, prolonged shorting
of a High output may raise the chip temperature well above normal and thereby cause invalid readings in other parameter tests. In any
sequence of parameter tests, IOS tests should be performed last.
1988 Nov 29
5
Philips Semiconductors
Product specification
Dual addressable latch
74F256
AC ELECTRICAL CHARACTERISTICS
LIMITS
SYMBOL
PARAMETER
TEST
CONDITION
Tamb = +25°C
VCC = +5V
CL = 50pF, RL = 500Ω
Tamb = 0°C to +70°C
VCC = +5V ± 10%
CL = 50pF, RL = 500Ω
UNIT
MIN
TYP
MAX
MIN
MAX
Waveform 2
4.0
3.0
7.0
5.0
9.5
7.0
4.0
2.5
10.0
7.5
ns
Propagation delay
E to Qn
Waveform 1
4.5
3.0
8.0
5.0
10.5
7.0
4.5
3.0
12.0
7.5
ns
tPLH
tPHL
Propagation delay
An to Qn
Waveform 3
5.0
4.5
10.0
8.5
14.0
9.5
5.0
4.0
14.5
10.0
ns
tPHL
Propagation delay
MR to Qn
Waveform 4
5.0
7.0
9.0
4.5
10.0
ns
tPLH
tPHL
Propagation delay
Dn to Qn
tPLH
tPHL
AC SETUP REQUIREMENTS
LIMITS
SYMBOL
PARAMETER
TEST
Tamb = +25°C
VCC = +5.0V
CONDITION
CL = 50pF, RL = 500Ω
MIN
TYP
MAX
Tamb = 0°C to +70°C
VCC = +5.0V ± 10%
CL= 50pF, RL = 500Ω
MIN
UNIT
MAX
ts(H)
ts(L)
Setup time, High or Low
Dn to E
Waveform 5
3.0
6.5
3.0
7.0
ns
th(H)
th(L)
Hold time, High or Low
Dn to E
Waveform 5
0
0
0
0
ns
ts(H)
ts(L)
Setup time, High or Low
An to E1
Waveform 6
2.0
2.0
2.0
2.0
ns
th(H)
th(L)
Hold time, High or Low
An to E2
Waveform 6
0
0
0
0
ns
tw(L)
E Pulse width, Low
Waveform 1
7.5
8.0
ns
tw(L)
MR Pulse width, Low
Waveform 4
3.0
3.0
ns
NOTES:
1. The Address to Enable setup time is the time before the High-to-Low Enable transition that the Address must be stable so that the correct
latch is addressed and the other latches are not affected.
2. The Address to Enable hold time is the time before the Low-to-High Enable transition that the Address must be stable so that the correct
latch is addressed and the other latches are not affected.
1988 Nov 29
6
Philips Semiconductors
Product specification
Dual addressable latch
74F256
AC WAVEFORMS
For all waveforms, VM = 1.5V.
The shaded areas indicate when the input is permitted to change for predictable output performance.
tW(L)
E
VM
Dn
VM
tPLH
tPHL
VM
VM
tPHL
tPLH
Qn
Qn
VM
VM
VM
VM
SF00809
SF00810
Waveform 1. Propagation Delay,
Enable Input to Output, Enable Pulse Width
Waveform 2. Propagation Delay,
Data to Output
tW(L)
An
VM
VM
tPHL
tPLH
VM
MR
tPHL
Qn
Qn
VM
VM
VM
VM
SF00811
SF00812
Waveform 3. Propagation Delay Address to Output
Waveform 4. Master Reset Pulse Width and
Master Reset to Output Delay
Dn
VM
VM
ts(H)
VM
th(H)
ts(L)
th(L)
E
VM
VM
E
An
VM
VM
Address Stable
VM
ts
th
VM
VM
SF00814
Q=D
Qn
Waveform 6. Address Setup and Hold Times
Q=D
SF00813
Waveform 5. Data Setup and Hold Times
1988 Nov 29
7
Philips Semiconductors
Product specification
Dual addressable latch
74F256
TEST CIRCUIT AND WAVEFORMS
VCC
NEGATIVE
PULSE
VIN
tw
90%
VM
D.U.T.
RT
CL
RL
AMP (V)
VM
10%
VOUT
PULSE
GENERATOR
90%
10%
tTHL (tf )
tTLH (tr )
tTLH (tr )
tTHL (tf )
0V
AMP (V)
90%
90%
POSITIVE
PULSE
DEFINITIONS:
RL = Load resistor;
see AC ELECTRICAL CHARACTERISTICS for value.
CL = Load capacitance includes jig and probe capacitance;
see AC ELECTRICAL CHARACTERISTICS for value.
RT = Termination resistance should be equal to ZOUT of
pulse generators.
VM
VM
10%
Test Circuit for Totem-Pole Outputs
10%
tw
0V
Input Pulse Definition
INPUT PULSE REQUIREMENTS
family
amplitude VM
74F
3.0V
1.5V
rep. rate
tw
tTLH
tTHL
1MHz
500ns
2.5ns
2.5ns
SF00006
1988 Nov 29
8
Philips Semiconductors
Product specification
Dual addressable latch
74F256
DIP16: plastic dual in-line package; 16 leads (300 mil)
1988 Nov 29
9
SOT38-4
Philips Semiconductors
Product specification
Dual addressable latch
74F256
SO16: plastic small outline package; 16 leads; body width 3.9 mm
1988 Nov 29
10
SOT109-1
Philips Semiconductors
Product specification
Dual addressable latch
74F256
NOTES
1988 Nov 29
11
Philips Semiconductors
Product specification
Dual addressable latch
74F256
Data sheet status
Data sheet
status
Product
status
Definition [1]
Objective
specification
Development
This data sheet contains the design target or goal specifications for product development.
Specification may change in any manner without notice.
Preliminary
specification
Qualification
This data sheet contains preliminary data, and supplementary data will be published at a later date.
Philips Semiconductors reserves the right to make chages at any time without notice in order to
improve design and supply the best possible product.
Product
specification
Production
This data sheet contains final specifications. Philips Semiconductors reserves the right to make
changes at any time without notice in order to improve design and supply the best possible product.
[1] Please consult the most recently issued datasheet before initiating or completing a design.
Definitions
Short-form specification — The data in a short-form specification is extracted from a full data sheet with the same type number and title. For
detailed information see the relevant data sheet or data handbook.
Limiting values definition — Limiting values given are in accordance with the Absolute Maximum Rating System (IEC 134). Stress above one
or more of the limiting values may cause permanent damage to the device. These are stress ratings only and operation of the device at these or
at any other conditions above those given in the Characteristics sections of the specification is not implied. Exposure to limiting values for extended
periods may affect device reliability.
Application information — Applications that are described herein for any of these products are for illustrative purposes only. Philips
Semiconductors make no representation or warranty that such applications will be suitable for the specified use without further testing or
modification.
Disclaimers
Life support — These products are not designed for use in life support appliances, devices or systems where malfunction of these products can
reasonably be expected to result in personal injury. Philips Semiconductors customers using or selling these products for use in such applications
do so at their own risk and agree to fully indemnify Philips Semiconductors for any damages resulting from such application.
Right to make changes — Philips Semiconductors reserves the right to make changes, without notice, in the products, including circuits, standard
cells, and/or software, described or contained herein in order to improve design and/or performance. Philips Semiconductors assumes no
responsibility or liability for the use of any of these products, conveys no license or title under any patent, copyright, or mask work right to these
products, and makes no representations or warranties that these products are free from patent, copyright, or mask work right infringement, unless
otherwise specified.
 Copyright Philips Electronics North America Corporation 1998
All rights reserved. Printed in U.S.A.
Philips Semiconductors
811 East Arques Avenue
P.O. Box 3409
Sunnyvale, California 94088–3409
Telephone 800-234-7381
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Document order number:
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Date of release: 10-98
9397-750-05106