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Электронный компонент: 74LV423N

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Philips
Semiconductors
74LV423
Dual retriggerable monostable
multivibrator with reset
Product specification
1997 Feb 04
INTEGRATED CIRCUITS
IC24 Data Handbook
Philips Semiconductors
Preliminary specification
74LV423
Dual retriggerable monostable multivibrator
with reset
2
1997 Feb 04
8531913 17724
FEATURES
Optimized for Low Voltage applications: 1.0 to 5.5V
Accepts TTL input levels between V
CC
= 2.7V and V
CC
= 3.6V
Typical V
OLP
(output ground bounce)
t
0.8V @ V
CC
= 3.3V,
T
amb
= 25
C
Typical V
OHV
(output V
OH
undershoot)
u
2V @ V
CC
= 3.3V,
T
amb
= 25
C
DC triggered from active HIGH or active LOW inputs
Retriggerable for very long pulses up to 100% duty factor
Direct reset terminates output pulses
Schmitt-trigger action on all inputs except for the reset input
Output capability: standard (except for nR
EXT
/C
EXT
)
I
CC
category: MSI
DESCRIPTION
The 74LV423 is a low-voltage Si-gate CMOS device and is pin and
function compatible with the 74HC/HCT423.
The 74LV423 is a dual retriggerable monostable multivibrator with
output pulse width control by three methods. The basic pulse time is
programmed by selection of an external resistor (R
EXT
) and
capacitor (C
EXT
). They are normally connected as shown in
Figure 1. Once triggered, the basic output pulse width may be
extended by retriggering the gated active LOW-going edge input
(nA) or the active HIGH-going edge input (nB). By repeating this
process, the output pulse period (nQ = HIGH, nQ = LOW) can be
made as long as desired. Alternatively, an output delay can be
terminated at any time by a LOW-going edge on input nR
D
, which
also inhibits the triggering. Figures 2 and 3 illustrate pulse control by
retriggering and early reset. The basic output pulse width is
essentially determined by the values of the external timing
components R
EXT
and C
EXT
. For pulse width when C
EXT
<10000pF,
see Figure 6. When C
EXT
u
10,000pF, the typical output pulse
width is defined as:
t
W
= 0.45
R
EXT
C
EXT
(typ.), where
t
W
= pulse width in ns; R
EXT
= external resistor in K
; and
C
EXT
= external capacitor in pF. Schmitt-trigger action in the nA and
nB inputs makes the circuit highly tolerant of slower input rise and
fall times.
QUICK REFERENCE DATA
GND = 0V; T
amb
= 25
C; t
r
= t
f
v
2.5 ns
SYMBOL
PARAMETER
CONDITIONS
TYPICAL
UNIT
t
PHL
/t
PLH
Propagation delay
nA, nB to nQ, nQ
nR
D
to nQ, nQ
C
L
= 15pF
V
CC
= 3.3V
R
EXT
= 5K
C
EXT
= 0pF
16
13
ns
ns
C
I
Input capacitance
3.5
pF
C
PD
Power dissipation capacitance per flip-flop
V
CC
= 3.3V, V
I
= GND to V
CC
1
17
pF
NOTES:
1. C
PD
is used to determine the dynamic power dissipation (P
D
in
W)
P
D
= C
PD
V
CC
2
f
i
)S
(C
L
V
CC
2
f
o
) where:
f
i
= input frequency in MHz; C
L
= output load capacity in pF;
f
o
= output frequency in MHz; V
CC
= supply voltage in V;
S
(C
L
V
CC
2
f
o
) = sum of the outputs.
ORDERING INFORMATION
PACKAGES
TEMPERATURE RANGE
OUTSIDE NORTH AMERICA
NORTH AMERICA
PKG. DWG. #
16-Pin Plastic DIL
40
C to +125
C
74LV423 N
74LV423 N
SOT38-1
16-Pin Plastic SO
40
C to +125
C
74LV423 D
74LV423 D
SOT109-1
16-Pin Plastic SSOP Type II
40
C to +125
C
74LV423 DB
74LV423 DB
SOT338-1
16-Pin Plastic TSSOP Type I
40
C to +125
C
74LV423 PW
74LV423PW DH
SOT403-1
Philips Semiconductors
Preliminary specification
74LV423
Dual retriggerable monostable multivibrator
with reset
1997 Feb 04
3
PIN CONFIGURATION
14
13
12
11
10
9
7
6
5
4
3
2
1
GND
V
CC
1A
1B
1R
D
1Q
2Q
8
15
16
2C
EXT
2R
EXT
/C
EXT
1R
EXT
/C
EXT
1C
EXT
1Q
2Q
2R
D
2B
2A
SV00096
PIN DESCRIPTION
PIN
NUMBER
SYMBOL
FUNCTION
1,9
1A, 2A
Trigger inputs
(negative-edge triggered)
2,10
1B, 2B
Trigger inputs
(positive-edge triggered)
3,11
1R
D
, 2R
D
Direct reset LOW
4, 12
1Q, 2Q
Outputs (active LOW)
7
2R
EXT
/C
EXT
External resistor/capacitor connection
8
GND
Ground (0V)
13, 5
1Q, 2Q
Outputs (active HIGH)
14, 6
1C
EXT,
2C
EXT
External capacitor connection
15
1R
EXT
/C
EXT
External resistor/capacitor connection
16
V
CC
Positive supply voltage
LOGIC SYMBOL (IEEE/IEC)
CX
RCX
&
R
14
15
1
2
3
13
4
CX
RCX
&
R
6
7
9
10
11
5
12
SV00161
LOGIC SYMBOL
1
9
2
10
3
11
14
6
15
7
13
5
4
12
1A
2A
1B
2B
1R
D
2R
D
1C
EXT
2C
EXT
1R
EXT
/C
EXT
2R
EXT
/C
EXT
1Q
2Q
1Q
2Q
S
Q
Q
R
D
T
SV00160
FUNCTIONAL DIAGRAM
1
9
2
10
3
11
14
6
15
7
13
5
4
12
1A
2A
1B
2B
1R
D
2R
D
1C
EXT
2C
EXT
1R
EXT
/C
EXT
2R
EXT
/C
EXT
1Q
2Q
1Q
2Q
S
Q
Q
R
D
T
SV00162
Philips Semiconductors
Preliminary specification
74LV423
Dual retriggerable monostable multivibrator
with reset
1997 Feb 04
4
LOGIC DIAGRAM
R
nR
EXT
/C
EXT
V
CC
Q
Q
R
D
R
R
CL
CL
V
CC
CL
CL
CL
A
B
SV00163
V
CC
It is recommended that Pin 6 (2C
EXT
) and Pin 14 (1C
EXT
) by externally grounded to Pin 8 (GND)
FUNCTION TABLE
INPUTS
OUTPUTS
nR
D
nA
nB
nQ
nQ
L
X
X
L
H
X
H
X
L *
H *
X
X
L
L *
H *
H
L
H
H
NOTES:
*
If the monostable was triggered before this condition was
established, the pulse will continue as programmed.
H = HIGH voltage level
L = LOW voltage level
X = don't care
= LOW-to-HIGH transition
= HIGH-to-LOW transition
= one HIGH level output pulse
= one LOW level output pulse
V
CC
R
EXT
C
EXT
to nC
EXT
(pin 14 or 6)
to nR
EXT
/C
EXT
(pin 15 or 7)
SV00101
Figure 1. Timing Component Connection
Philips Semiconductors
Preliminary specification
74LV423
Dual retriggerable monostable multivibrator
with reset
1997 Feb 04
5
ABSOLUTE MAXIMUM RATINGS
1, 2
In accordance with the Absolute Maximum Rating System (IEC 134).
Voltages are referenced to GND (ground = 0V).
SYMBOL
PARAMETER
CONDITIONS
RATING
UNIT
V
CC
DC supply voltage
0.5 to +7.0
V
"
I
IK
DC input diode current
V
I
< 0.5 or V
I
> V
CC
+ 0.5V
20
mA
"
I
OK
DC output diode current
V
O
< 0.5 or V
O
> V
CC
+ 0.5V
50
mA
"
I
O
DC output source or sink current
standard outputs
bus driver outputs
0.5V < V
O
< V
CC
+ 0.5V
25
35
mA
"
I
GND
,
"
I
CC
DC V
CC
or GND current for types with
standard outputs
bus driver outputs
50
70
mA
T
stg
Storage temperature range
65 to +150
C
P
TOT
Power dissipation per package
plastic DIL
plastic mini-pack (SO)
plastic shrink mini-pack (SSOP and TSSOP)
for temperature range: 40 to +125
C
above +70
C derate linearly with 12 mW/K
above +70
C derate linearly with 8 mW/K
above +60
C derate linearly with 5.5 mW/K
750
500
500
mW
NOTES:
1. Stresses beyond those listed may cause permanent damage to the device. These are stress ratings only and functional operation of the
device at these or any other conditions beyond those indicated under "recommended operating conditions" is not implied. Exposure to
absolute-maximum-rated conditions for extended periods may affect device reliability.
2. The input and output voltage ratings may be exceeded if the input and output current ratings are observed.
RECOMMENDED OPERATING CONDITIONS
SYMBOL
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNIT
V
CC
DC supply voltage
See Note 1
1.2
3.3
5.5
V
V
I
Input voltage
0
V
CC
V
V
O
Output voltage
0
V
CC
V
T
amb
Operating ambient temperature range in free
air
See DC and AC
characteristics per device
40
40
+85
+125
C
t
r
, t
f
Input rise and fall times except for
Schmitt-trigger inputs
V
CC
= 1.0V to 2.0V
V
CC
= 2.0V to 2.7V
V
CC
= 2.7V to 3.6V
V
CC
= 3.6V to 5.5V





500
200
100
50
ns/V
NOTE:
1. The LV is guaranteed to function down to V
CC
= 1.0V (input levels GND or V
CC
); DC characteristics are guaranteed from V
CC
= 1.2V to V
CC
= 5.5V.