2001 Fairchild Semiconductor Corporation
DS500690
www.fairchildsemi.com
November 2001
Revised November 2001
7
4
AL
VC1684
1
Low V
o
l
t
a
g
e
20-
Bit
T
r
anspar
ent Lat
c
h
wi
th 3.6V T
o
ler
a
nt
I
nputs and O
u
tput
s
74ALVC16841
Low Voltage 20-Bit Transparent Latch
with 3.6V Tolerant Inputs and Outputs
General Description
The ALVC16841 contains twenty non-inverting latches with
3-STATE outputs and is intended for bus oriented applica-
tions. The device is byte controlled. The flip-flops appear
transparent to the data when the Latch enable (LE) is
HIGH. When LE is LOW, the data that meets the setup time
is latched. Data appears on the bus when the Output
Enable (OE) is LOW. When OE is HIGH, the outputs are in
a high impedance state.
The 74ALVC16841 is designed for low voltage (1.65V to
3.6V) V
CC
applications with I/O compatibility up to 3.6V.
The 74ALVC16841 is fabricated with an advanced CMOS
technology to achieve high speed operation while maintain-
ing low CMOS power dissipation.
Features
I
1.65V3.6V V
CC
supply operation
I
3.6V tolerant inputs and outputs
I
t
PD
(D
n
to O
n
)
3.5 ns max for 3.0V to 3.6V V
CC
3.9 ns max for 2.3V to 2.7V V
CC
6.8 ns max for 1.65V to 1.95V V
CC
I
Power-off high impedance inputs and outputs
I
Supports live insertion and withdrawal (Note 1)
I
Uses patented noise/EMI reduction circuitry
I
Latchup conforms to JEDEC JED78
I
ESD performance:
Human body model
>
2000V
Machine model
>
200V
Note 1: To ensure the high-impedance state during power up or power
down, OE should be tied to V
CC
through a pull-up resistor; the minimum
value of the resistor is determined by the current-sourcing capability of the
driver.
Ordering Code:
Device also available in Tape and Reel. Specify by appending suffix letter "X" to the ordering code.
Logic Symbol
Pin Descriptions
Order Number
Package Number
Package Description
74ALVC16841MTD
MTD56
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Pin Names
Description
OE
n
Output Enable Input (Active LOW)
LE
n
Latch Enable Input
D
0
D
19
Inputs
O
0
O
19
Outputs
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2
74
A
L
VC16841
Connection Diagram
Truth Tables
H
=
HIGH Voltage Level
L
=
LOW Voltage Level
X
=
Immaterial (HIGH or LOW, inputs may not float)
Z
=
High Impedance
O
0
=
Previous O
0
before HIGH-to-LOW of Latch Enable
Functional Description
The 74ALVC16841 contains twenty D-type latches with
3-STATE outputs. The device is byte controlled with each
byte functioning identically, but independent of the other.
Control pins can be shorted together to obtain full 20-bit
operation. The following description applies to each byte.
When the Latch Enable (LE
n
) input is HIGH, data on the D
n
enters the latches. In this condition the latches are trans-
parent, i.e., a latch output will change states each time its
D-type input changes. When LE
n
is LOW, the latches store
information that was present on the D-type inputs a setup
time preceding the HIGH-to-LOW transition on LE
n
. The
3-STATE outputs are controlled by the Output Enable
(OE
n
) input. When OE
n
is LOW the standard outputs are in
the 2-state mode. When OE
n
is HIGH, the standard outputs
are in the high impedance mode but this does not interfere
with entering new data into the latches.
Logic Diagram
Please note that this diagram is provided only for the understanding of logic operations and should not be used to estimate propagation delays.
Inputs
Outputs
LE
1
OE
1
D
0
D
9
O
0
O
9
X
H
X
Z
H
L
L
L
H
L
H
H
L
L
X
O
0
Inputs
Outputs
LE
2
OE
2
D
10
D
19
O
10
O
19
X
H
X
Z
H
L
L
L
H
L
H
H
L
L
X
O
0
3
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7
4
AL
VC1684
1
Absolute Maximum Ratings
(Note 2)
Recommended Operating
Conditions
(Note 4)
Note 2: The Absolute Maximum Ratings are those values beyond which
the safety of the device cannot be guaranteed. The device should not be
operated at these limits. The parametric values defined in the Electrical
Characteristics tables are not guaranteed at the Absolute Maximum Rat-
ings. The "Recommended Operating Conditions" table will define the condi-
tions for actual device operation.
Note 3: I
O
Absolute Maximum Rating must be observed.
Note 4: Floating or unused inputs must be held HIGH or LOW.
DC Electrical Characteristics
Supply Voltage (V
CC
)
-
0.5V to
+
4.6V
DC Input Voltage (V
I
)
-
0.5V to 4.6V
Output Voltage (V
O
) (Note 3)
-
0.5V to V
CC
+
0.5V
DC Input Diode Current (I
IK
)
V
I
<
0V
-
50 mA
DC Output Diode Current (I
OK
)
V
O
<
0V
-
50 mA
DC Output Source/Sink Current
(I
OH
/I
OL
)
50 mA
DC V
CC
or GND Current per
Supply Pin (I
CC
or GND)
100 mA
Storage Temperature Range (T
STG
)
-
65
C to
+
150
C
Power Supply
Operating
1.65V to 3.6V
Input Voltage (V
I
)
0V to V
CC
Output Voltage (V
O
)
0V to V
CC
Free Air Operating Temperature (T
A
)
-
40
C to
+
85
C
Minimum Input Edge Rate (
t/
V)
V
IN
=
0.8V to 2.0V, V
CC
=
3.0V
10 ns/V
Symbol
Parameter
Conditions
V
CC
Min
Max
Units
(V)
V
IH
HIGH Level Input Voltage
1.65 -1.95
0.65 x V
CC
V
2.3 - 2.7
1.7
2.7 - 3.6
2.0
V
IL
LOW Level Input Voltage
1.65 -1.95
0.35 x V
CC
V
2.3 - 2.7
0.7
2.7 - 3.6
0.8
V
OH
HIGH Level Output Voltage
I
OH
=
-
100
A
1.65 - 3.6
V
CC
- 0.2
V
I
OH
=
-
4 mA
1.65
1.2
I
OH
=
-
6 mA
2.3
2
I
OH
=
-
12 mA
2.3
1.7
2.7
2.2
3.0
2.4
I
OH
=
-
24 mA
3.0
2
V
OL
LOW Level Output Voltage
I
OL
=
100
A
1.65 - 3.6
0.2
V
I
OL
=
4 mA
1.65
0.45
I
OL
=
6 mA
2.3
0.4
I
OL
=
12mA
2.3
0.7
2.7
0.4
I
OL
=
24 mA
3
0.55
I
I
Input Leakage Current
0
V
I
3.6V
3.6
5.0
A
I
OZ
3-STATE Output Leakage
0
V
O
3.6V
3.6
10
A
I
CC
Quiescent Supply Current
V
I
=
V
CC
or GND, I
O
=
0
3.6
40
A
I
CC
Increase in I
CC
per Input
V
IH
=
V
CC
-
0.6V
3 -3.6
750
A
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4
74
A
L
VC16841
AC Electrical Characteristics
Capacitance
Symbol
Parameter
T
A
=
-
40
C to
+
85
C, R
L
=
500
Units
C
L
=
50 pF
C
L
=
30 pF
V
CC
=
3.3V
0.3V
V
CC
=
2.7V
V
CC
=
2.5V
0.2V
V
CC
=
1.8V
0.15V
Min
Max
Min
Max
Min
Max
Min
Max
t
PHL
, t
PLH
Propagation Delay
1.3
3.5
1.5
3.9
1.0
3.4
1.5
6.8
ns
Bus to Bus
t
PHL
, t
PLH
Propagation Delay
1.3
4.0
1.5
4.9
1.0
4.4
1.5
8.8
ns
LE to Bus
t
PZL
, t
PZH
Output Enable Time
1.3
4.3
1.5
5.4
1.0
4.9
1.5
9.8
ns
t
PLZ
, t
PHZ
Output Disable Time
1.3
4.2
1.5
4.7
1.0
4.2
1.5
7.6
ns
t
W
Pulse Width
1.5
1.5
1.5
4.0
ns
t
S
Setup Time
1.5
1.5
1.5
2.5
ns
t
H
Hold Time
1.0
1.0
1.0
1.0
ns
Symbol
Parameter
Conditions
T
A
=
+
25
C
Units
V
CC
Typical
C
IN
Input Capacitance
V
I
=
0V or V
CC
3.3
6
pF
C
OUT
Output Capacitance
V
I
=
0V or V
CC
3.3
7
pF
C
PD
Power Dissipation Capacitance Outputs Enabled f
=
10 MHz, C
L
=
50 pF
3.3
20
pF
2.5
20
5
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7
4
AL
VC1684
1
AC Loading and Waveforms
FIGURE 1. AC Test Circuit
TABLE 1. Values for Figure 1
TABLE 2. Variable Matrix
(Input Characteristics: f
=
1MHz; t
r
=
t
f
=
2ns; Z
0
=
50
)
FIGURE 2. Waveform for Inverting and
Non-Inverting Functions
FIGURE 3. 3-STATE Output High Enable and
Disable Times for Low Voltage Logic
FIGURE 4. 3-STATE Output Low Enable and Disable Times for Low Voltage Logic
FIGURE 5. Propagation Delay, Pulse Width and
t
rec
Waveforms
FIGURE 6. Setup Time, Hold Time and
Recovery Time for Low Voltage Logic
TEST
SWITCH
t
PLH
, t
PHL
Open
t
PZL
, t
PLZ
V
L
t
PZH
, t
PHZ
GND
Symbol
V
CC
3.3V
0.3V
2.7V
2.5V
0.2V
1.8V
0.15V
V
mi
1.5V
1.5V
V
CC
/2
V
CC
/2
V
mo
1.5V
1.5V
V
CC
/2
V
CC
/2
V
X
V
OL
+
0.3V
V
OL
+
0.3V
V
OL
+
0.15V
V
OL
+
0.15V
V
Y
V
OH
-
0.3V
V
OH
-
0.3V
V
OH
-
0.15V
V
OH
-
0.15V
V
L
6V
6V
V
CC
*2
V
CC
*2
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6
74AL
VC16841 Low
V
o
l
t
age 20-
Bit
T
r
anspar
ent Latch
wit
h
3.6V T
o
ler
ant Inp
u
ts and O
u
t
puts
Physical Dimensions
inches (millimeters) unless otherwise noted
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Package Number MTD56
Fairchild does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and
Fairchild reserves the right at any time without notice to change said circuitry and specifications.
LIFE SUPPORT POLICY
FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT
DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD
SEMICONDUCTOR CORPORATION. As used herein:
1. Life support devices or systems are devices or systems
which, (a) are intended for surgical implant into the
body, or (b) support or sustain life, and (c) whose failure
to perform when properly used in accordance with
instructions for use provided in the labeling, can be rea-
sonably expected to result in a significant injury to the
user.
2. A critical component in any component of a life support
device or system whose failure to perform can be rea-
sonably expected to cause the failure of the life support
device or system, or to affect its safety or effectiveness.
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