74ALVC16841 Low Voltage 20-Bit Transparent Latch with 3.6V Tolerant Inputs and Outputs
November 2001
Revised November 2001
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
1.65V–3.6V 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:
Order Number
74ALVC16841MTD
Package Number
MTD56
Package Description
56-Lead Thin Shrink Small Outline Package (TSSOP), JEDEC MO-153, 6.1mm Wide
Device also available in Tape and Reel. Specify by appending suffix letter “X” to the ordering code.
Logic Symbol
Pin Descriptions
Pin Names
OE
n
LE
n
D
0
–D
19
O
0
–O
19
Description
Output Enable Input (Active LOW)
Latch Enable Input
Inputs
Outputs
© 2001 Fairchild Semiconductor Corporation
DS500690
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74ALVC16841
Connection Diagram
Truth Tables
Inputs
LE
1
X
H
H
L
OE
1
H
L
L
L
Inputs
LE
2
X
H
H
L
OE
2
H
L
L
L
D
10
–D
19
X
L
H
X
D
0
–D
9
X
L
H
X
Outputs
O
0
–O
9
Z
L
H
O
0
Outputs
O
10
–O
19
Z
L
H
O
0
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.
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2
74ALVC16841
Absolute Maximum Ratings
(Note 2)
Supply Voltage (V
CC
)
DC Input Voltage (V
I
)
Output Voltage (V
O
) (Note 3)
DC Input Diode Current (I
IK
)
V
I
<
0V
DC Output Diode Current (I
OK
)
V
O
<
0V
DC Output Source/Sink Current
(I
OH
/I
OL
)
DC V
CC
or GND Current per
Supply Pin (I
CC
or GND)
Storage Temperature Range (T
STG
)
−
0.5V to
+
4.6V
−
0.5V to 4.6V
−
0.5V to V
CC
+
0.5V
−
50 mA
−
50 mA
±
50 mA
±
100 mA
−
65
°
C to
+
150
°
C
Recommended Operating
Conditions
(Note 4)
Power Supply
Operating
Input Voltage (V
I
)
Output Voltage (V
O
)
Free Air Operating Temperature (T
A
)
Minimum Input Edge Rate (
∆
t/
∆
V)
V
IN
=
0.8V to 2.0V, V
CC
=
3.0V
10 ns/V
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.
1.65V to 3.6V
0V to V
CC
0V to V
CC
−
40
°
C to
+
85
°
C
DC Electrical Characteristics
Symbol
V
IH
Parameter
HIGH Level Input Voltage
Conditions
V
CC
(V)
1.65 -1.95
2.3 - 2.7
2.7 - 3.6
V
IL
LOW Level Input Voltage
1.65 -1.95
2.3 - 2.7
2.7 - 3.6
V
OH
HIGH Level Output Voltage
I
OH
= −100 µA
I
OH
= −4
mA
I
OH
= −6
mA
I
OH
= −12
mA
1.65 - 3.6
1.65
2.3
2.3
2.7
3.0
I
OH
= −24
mA
V
OL
LOW Level Output Voltage
I
OL
=
100
µA
I
OL
=
4 mA
I
OL
=
6 mA
I
OL
=
12mA
I
OL
=
24 mA
I
I
I
OZ
I
CC
∆I
CC
Input Leakage Current
3-STATE Output Leakage
Quiescent Supply Current
Increase in I
CC
per Input
0
≤
V
I
≤
3.6V
0
≤
V
O
≤
3.6V
V
I
=
V
CC
or GND, I
O
=
0
V
IH
=
V
CC
−
0.6V
3.0
1.65 - 3.6
1.65
2.3
2.3
2.7
3
3.6
3.6
3.6
3 -3.6
V
CC
- 0.2
1.2
2
1.7
2.2
2.4
2
0.2
0.45
0.4
0.7
0.4
0.55
±5.0
±10
40
750
µA
µA
µA
µA
V
V
Min
0.65 x V
CC
1.7
2.0
0.35 x V
CC
0.7
0.8
V
V
Max
Units
3
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74ALVC16841
AC Electrical Characteristics
T
A
= −40°C
to
+85°C,
R
L
=
500Ω
Symbol
Parameter
C
L
=
50 pF
V
CC
=
3.3V
±
0.3V
Min
t
PHL
, t
PLH
t
PHL
, t
PLH
t
PZL
, t
PZH
t
PLZ
, t
PHZ
t
W
t
S
t
H
Propagation Delay
Bus to Bus
Propagation Delay
LE to Bus
Output Enable Time
Output Disable Time
Pulse Width
Setup Time
Hold Time
1.3
1.3
1.3
1.3
1.5
1.5
1.0
Max
3.5
4.0
4.3
4.2
V
CC
=
2.7V
Min
1.5
1.5
1.5
1.5
1.5
1.5
1.0
Max
3.9
4.9
5.4
4.7
C
L
=
30 pF
V
CC
=
2.5V
±
0.2V
Min
1.0
1.0
1.0
1.0
1.5
1.5
1.0
Max
3.4
4.4
4.9
4.2
V
CC
=
1.8V
±
0.15V
Min
1.5
1.5
1.5
1.5
4.0
2.5
1.0
Max
6.8
8.8
9.8
7.6
ns
ns
ns
ns
ns
ns
ns
Units
Capacitance
Symbol
C
IN
C
OUT
C
PD
Input Capacitance
Output Capacitance
Power Dissipation Capacitance
Parameter
V
I
=
0V or V
CC
V
I
=
0V or V
CC
Outputs Enabled f
=
10 MHz, C
L
=
50 pF
Conditions
T
A
= +25°C
V
CC
3.3
3.3
3.3
2.5
Typical
6
7
20
20
Units
pF
pF
pF
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4
74ALVC16841
AC Loading and Waveforms
TABLE 1. Values for Figure 1
TEST
t
PLH
, t
PHL
t
PZL
, t
PLZ
t
PZH
, t
PHZ
SWITCH
Open
V
L
GND
FIGURE 1. AC Test Circuit
TABLE 2. Variable Matrix
(Input Characteristics: f
=
1MHz; t
r
=
t
f
=
2ns; Z
0
=
50
Ω
)
Symbol
V
mi
V
mo
V
X
V
Y
V
L
V
CC
3.3V
±
0.3V
1.5V
1.5V
V
OL
+
0.3V
V
OH
−
0.3V
6V
2.7V
1.5V
1.5V
V
OL
+
0.3V
V
OH
−
0.3V
6V
2.5V
±
0.2V
V
CC
/2
V
CC
/2
V
OL
+
0.15V
V
OH
−
0.15V
V
CC
*2
1.8V
±
0.15V
V
CC
/2
V
CC
/2
V
OL
+
0.15V
V
OH
−
0.15V
V
CC
*2
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
5
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