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74LCX16821 Low Voltage 20-Bit D-Type Flip-Flop with 5V Tolerant Inputs and Outputs
January 1996
Revised April 1999
74LCX16821
Low Voltage 20-Bit D-Type Flip-Flop with 5V Tolerant
Inputs and Outputs
General Description
The LCX16821 contains twenty non-inverting D-type flip-
flops with 3-STATE outputs and is intended for bus oriented
applications. The device is designed for low voltage (2.5V
or 3.3V) V
CC
applications with capability of interfacing to a
5V signal environment.
The LCX16821 is fabricated with an advanced CMOS tech-
nology to achieve high speed operation while maintaining
CMOS low power dissipation.
Features
s
5V tolerant inputs and outputs
s
2.3V–3.6V V
CC
specifications provided
s
6.2 ns t
PD
max (V
CC
=
3.3V), 20
µA
I
CC
max
s
Power down high impedance inputs and outputs
s
Supports live insertion/withdrawal (Note 1)
s
±24
mA output drive (V
CC
=
3.0V)
s
Implements patented noise/EMI reduction circuitry
s
Latch-up performance exceeds 500 mA
s
ESD performance:
Human body model
>
2000V
Machine model
>
200V
Note 1:
To ensure the high-impedance state during power up or down, OE
should be tied to V
CC
through a pull-up resistor: the minimum value or the
resistor is determined by the current-sourcing capability of the driver.
Ordering Code:
Order Number
74LCX16821MEA
74LCX16821MTD
Package Number
MS56A
MTD56
Package Description
56-Lead Shrink Small Outline Package (SSOP), JEDEC MO-118, 0.300” Wide
The LCX16821 contains twenty D-type flip-flops with 3-
STATE standard 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. The twenty flip-flops will store the state of their indi-
vidual D inputs that meet the setup and hold time require-
ments on the LOW-to-HIGH Clock (CLK) transition. The 3-
STATE standard outputs are controlled by the Output
Enable (OE
n
) input. When OE
n
is LOW, the standard out-
puts are in the 2-state mode. When OE
n
is HIGH, the stan-
dard outputs are in the high impedance mode but this does
not interfere with entering new data into the flip-flops.
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
74LCX16821
Absolute Maximum Ratings
(Note 3)
Symbol
V
CC
V
I
V
O
I
IK
I
OK
I
O
I
CC
I
GND
T
STG
Parameter
Supply Voltage
DC Input Voltage
DC Output Voltage
DC Input Diode Current
DC Output Diode Current
DC Output Source/Sink Current
DC Supply Current per Supply Pin
DC Ground Current per Ground Pin
Storage Temperature
Value
−0.5
to
+7.0
−0.5
to
+7.0
−0.5
to
+7.0
−0.5
to V
CC
+
0.5
−50
−50
+50
±50
±100
±100
−65
to
+150
(Note 4)
Min
Operating
Data Retention
V
I
V
O
I
OH
/I
OL
Input Voltage
Output Voltage
Output Current
HIGH or LOW State
3-STATE
V
CC
=
3.0V
−
3.6V
V
CC
=
2.7V
−
3.0V
V
CC
=
2.3V
−
2.7V
T
A
∆t/∆V
Free-Air Operating Temperature
Input Edge Rate, V
IN
=
0.8V – 2.0V, V
CC
=
3.0V
−40
0
2.0
1.5
0
0
0
Max
3.6
3.6
5.5
V
CC
5.5
±24
±12
±8
85
10
°C
ns/V
mA
Units
V
V
V
Output in 3-STATE
Output in HIGH or LOW State (Note 3)
V
I
<
GND
V
O
<
GND
V
O
>
V
CC
Conditions
Units
V
V
V
mA
mA
mA
mA
mA
°C
Recommended Operating Conditions
Symbol
V
CC
Supply Voltage
Parameter
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 Ratings. The “Recom-
mended Operating Conditions” table will define the conditions for actual device operation.
Note 3:
I
O
Absolute Maximum Rating must be observed.
Note 4:
Unused pins (Inputs and I/O) must be held HIGH or LOW. They may not float.
DC Electrical Characteristics
Symbol
V
IH
V
IL
V
OH
Parameter
HIGH Level Input Voltage
LOW Level Input Voltage
HIGH Level Output Voltage
I
OH
= −100 µA
I
OH
= −8
mA
I
OH
= −12
mA
I
OH
= −18
mA
I
OH
= −24
mA
V
OL
LOW Level Output Voltage
I
OL
=
100
µA
I
OL
=
8 mA
I
OL
=
12 mA
I
OL
=
16 mA
I
OL
=
24 mA
I
I
I
OZ
I
OFF
Input Leakage Current
3-STATE Output Leakage
Power-Off Leakage Current
0
≤
V
I
≤
5.5V
0
≤
V
O
≤
5.5V
V
I
=
V
IH
or V
IL
V
I
or V
O
=
5.5V
0
10
Conditions
V
CC
(V)
2.3
−
2.7
2.7
−
3.6
2.3
−
2.7
2.7
−
3.6
2.3
−
3.6
2.3
2.7
3.0
3.0
2.3
−
3.6
2.3
2.7
3.0
3.0
2.3
−
3.6
2.3
−
3.6
V
CC
−
0.2
1.8
2.2
2.4
2.2
0.2
0.6
0.4
0.4
0.55
±5.0
±5.0
µA
µA
µA
V
V
T
A
= −40°C
to
+85°C
Min
1.7
2.0
0.7
0.8
Max
V
V
Units
3
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74LCX16821
DC Electrical Characteristics
Symbol
I
CC
∆I
CC
Parameter
Quiescent Supply Current
Increase in I
CC
per Input
(Continued)
T
A
= −40°C
to
+85°C
Min
Max
20
±20
500
µA
µA
Conditions
V
I
=
V
CC
or GND
3.6V
≤
V
I
, V
O
≤
5.5V (Note 5)
V
IH
=
V
CC
−0.6V
V
CC
(V)
2.3
−
3.6
2.3
−
3.6
2.3
−
3.6
Units
Note 5:
Outputs disabled or 3-STATE only.
AC Electrical Characteristics
T
A
= −40°C
to
+85°C,
R
L
=
500Ω
Symbol
Parameter
V
CC
=
3.3V
±
0.3V
C
L
=
50 pF
Min
f
MAX
t
PHL
t
PLH
t
PZL
t
PZH
t
PLZ
t
PHZ
t
OSHL
t
OSLH
t
S
t
H
t
W
Setup Time, D
n
to CLK
Hold Time, D
n
to CLK
CLK Pulse Width
2.5
1.5
3.3
Output to Output Skew (Note 6)
Output Disable Time
Maximum Clock Frequency
Propagation Delay
CLK to O
n
Output Enable Time
150
1.5
1.5
1.5
1.5
1.5
1.5
6.2
6.2
6.5
6.5
6.5
6.5
1.0
1.0
2.5
1.5
3.3
3.0
2.0
3.8
1.5
1.5
1.5
1.5
1.5
1.5
6.5
6.5
7.0
7.0
7.0
7.0
1.5
1.5
1.5
1.5
1.5
1.5
7.4
7.4
8.5
8.5
7.8
7.8
Max
V
CC
=
2.7V
C
L
=
50 pF
Min
Max
V
CC
=
2.5V
±
0.2V
C
L
=
30 pF
Min
Max
MHz
ns
ns
ns
ns
ns
ns
ns
Units
Note 6:
Skew is defined as the absolute value of the difference between the actual propagation delay for any two separate outputs of the same device. The
specification applies to any outputs switching in the same direction, either HIGH-to-LOW (t