NSC DM74121N One-shot with clear and complementary output Datasheet

54121/DM54121/DM74121 One-Shot with
Clear and Complementary Outputs
Y
General Description
Y
The DM54/74121 is a monostable multivibrator featuring
both positive and negative edge triggering with complementary outputs. An internal 2kX timing resistor is provided for
design convenience minimizing component count and layout problems. This device can be used with a single external
capacitor. Inputs (A) are active-low trigger transition inputs
and input (B) is an active-high transition Schmitt-trigger input that allows jitter-free triggering from inputs with transition rates as slow as 1 volt/second. A high immunity to
VCC noise of typically 1.5V is also provided by internal circuitry at the input stage.
To obtain optimum and trouble free operation please read
operating rules and NSC one-shot application notes carefully and observe recommendations.
Features
Y
Y
Triggered from active-high transition or active-low transition inputs
Variable pulse width from 30 ns to 28 seconds
Connection Diagram
Y
Y
Y
Y
Y
Jitter free Schmitt-trigger input
Excellent noise immunity typically 1.2V
Stable pulse width up to 90% duty cycle
TTL, DTL compatible
Compensated for VCC and temperature variations
Input clamp diodes
Alternate Military/Aerospace device (54121) is available. Contact a National Semiconductor Sales Office/
Distributor for specifications.
Functional Description
The basic output pulse width is determined by selection of
an internal resistor RINT or an external resistor (RX) and
capacitor (CX). Once triggered the output pulse width is independent of further transitions of the inputs and is a function of the timing components. Pulse width can vary from a
few nano-seconds to 28 seconds by choosing appropriate
RX and CX combinations. There are three trigger inputs from
the device, two negative edge-triggering (A) inputs, one positive edge Schmitt-triggering (B) input.
Function Table
Inputs
Dual-In-Line Package
TL/F/6538 – 1
Order Number 54121DMQB, 54121FMQB,
DM54121J, DM54121W or DM74121N
See NS Package Number J14A, N14A or W14B
C1995 National Semiconductor Corporation
TL/F/6538
Outputs
A1
A2
B
Q
Q
L
X
X
H
H
X
L
X
H
v
v
v
v
H
H
L
X
H
H
H
L
X
X
L
u
u
L
L
L
L
É
É
É
É
É
H
H
H
H
ß
ß
ß
ß
ß
H
H
e High Logic Level
L
e Low Logic Level
X
e Can Be Either Low or High
u
v
e Positive Going Transition
e Negative Going Transition
É e A Positive Pulse
ß e A Negative Pulse
RRD-B30M105/Printed in U. S. A.
54121/DM54121/DM74121 One-Shot with Clear and Complementary Outputs
June 1989
Absolute Maximum Ratings (Note)
Note: 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’’
table are not guaranteed at the absolute maximum ratings.
The ‘‘Recommended Operating Conditions’’ table will define
the conditions for actual device operation.
If Military/Aerospace specified devices are required,
please contact the National Semiconductor Sales
Office/Distributors for availability and specifications.
Supply Voltage
7V
Input Voltage
5.5V
Operating Free Air Temperature Range
b 55§ C to a 125§ C
DM54
DM74
0§ C to a 70§ C
Storage Temperature Range
b 65§ C to a 150§ C
Recommended Operating Conditions
Symbol
DM54121
Parameter
VCC
Supply Voltage
VT a
Positive-Going Input Threshold
Voltage at the A Input (VCC e Min)
VTb
Negative-Going Input Threshold
Voltage at the A Input (VCC e Min)
VT a
Positive-Going Input Threshold
Voltage at the B Input (VCC e Min)
VTb
Negative-Going Input Threshold
Voltage at the B Input (VCC e Min)
DM74121
Nom
Max
Min
Nom
Max
4.5
5
5.5
4.75
5
5.25
V
1.4
2
1.4
2
V
0.8
1.4
1.5
0.8
0.8
2
1.3
IOH
High Level Output Current
IOL
Low Level Output Current
16
tW
Input Pulse Width (Note 1)
dV/dt
Rate of Rise or Fall of
Schmidt Input (B) (Note 1)
dV/dt
Rate of Rise or Fall of
Logic Input (A) (Note 1)
REXT
External Timing Resistor (Note 1)
CEXT
External Timing Capacitance (Note 1)
DC
Duty Cycle (Note 1)
40
1.4
V
1.5
0.8
b 0.4
TA
Units
Min
2
1.3
V
b 0.4
mA
16
mA
40
ns
1
1
1
V/s
1
V/ms
1.4
30
1.4
40
kX
0
1000
0
1000
mF
RT e 2 kX
67
67
RT e REXT (Max)
90
90
Free Air Operating Temperature
V
b 55
125
0
70
%
§C
Note 1: TA e 25§ C and VCC e 5V.
Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted)
Symbol
Parameter
Conditions
Min
Typ
(Note 1)
Max
Units
b 1.5
V
VI
Input Clamp Voltage
VOH
High Level Output
Voltage
VCC e Min, II e b12 mA
VCC e Min, IOH e Max,
VIL e Max, VIH e Min
VOL
Low Level Output
Voltage
VCC e Min, IOL e Max,
VIH e Min, VIL e Max
II
Input Current
Input Voltage
VCC e Max, VI e 5.5V
IIH
High Level Input
Current
VCC e Max
VI e 2.4V
A1, A2
40
B
80
Low Level Input
Current
VCC e Max
VI e 0.4V
A1, A2
b 1.6
B
b 3.2
Short Circuit
Output Current
VCC e Max
(Note 2)
Supply Current
VCC e Max
IIL
IOS
ICC
@
Max
2.4
3.4
0.2
V
0.4
V
1
mA
DM54
b 20
b 55
DM74
b 18
b 55
Quiescent
13
25
Triggered
23
40
Note 1: All typicals are at VCC e 5V, TA e 25§ C.
Note 2: Not more than one output should be shorted at a time.
2
mA
mA
mA
mA
Switching Characteristics
at VCC e 5V and TA e 25§ C (See Section 1 for Test Waveforms and Outout Load)
Parameter
From (Input)
To (Output)
tPLH
Propagation Delay Time
Low to High Level Output
A1, A2
to Q
tPLH
Propagation Delay Time
Low to High Level Output
B to
Q
tPHL
Propagation Delay Time
High to Low Level Output
tPHL
Propagation Delay Time
High to Low Level Output
tW(OUT)
Output Pulse
Width Using the
Internal Timing Resistor
Symbol
tW(OUT)
tW(OUT)
Conditions
Min
Max
Units
70
ns
55
ns
A1, A2
to Q
80
ns
B
to Q
65
ns
150
ns
50
ns
600
800
ns
6
8
ms
CEXT e 80 pF
RINT to VCC
CL e 15 pF
RL e 400X
A1, A2 or B
to Q, Q
CEXT e 80 pF
RINT to VCC
RL e 400X
CL e 15 pF
Output Pulse
Width Using Zero
Timing Capacitance
A1, A2
to Q, Q
CEXT e 0 pF
RINT to VCC
RL e 400X
CL e 15 pF
Output Pulse
Width Using External
Timing Resistor
A1, A2
to Q, Q
CEXT e 100 pF
RINT e 10 kX
RL e 400X
CL e 15 pF
A1, A2
to Q, Q
CEXT e 1 mF
RINT e 10 kX
RL e 400X
CL e 15 pF
70
Operating Rules
1. To use the internal 2 kX timing resistor, connect the RINT
pin to VCC.
2. An external resistor (RX) or the internal resistor (2 kX)
and an external capacitor (CX) are required for proper
operation. The value of CX may vary from 0 to any necessary value. For small time constants use high-quality
mica, glass, polypropylene, polycarbonate, or polystyrene
capacitors. For large time constants use solid tantalum or
special aluminum capacitors. If the timing capacitors
have leakages approaching 100 nA or if stray capacitance from either terminal to ground is greater than 50 pF
the timing equations may not represent the pulse width
the device generates.
3. The pulse width is essentially determined by external timing components RX and CX. For CX k 1000 pF see Figure 1 design curves on TW as function of timing components value. For CX l1000 pF the output is defined as:
tW e K RX CX
where [RX is in Kilo-ohm]
[CX is in pico Farad]
[TW is in nano second]
[K & 0.7]
TL/F/6538 – 2
FIGURE 1
4. If CX is an electrolytic capacitor a switching diode is often
required for standard TTL one-shots to prevent high inverse leakage current (Figure 2) .
TL/F/6538 – 3
FIGURE 2
3
Operating Rules (Continued)
5. Output pulse width versus VCC and operation temperatures: Figure 3 depicts the relationship between pulse
width variation versus VCC. Figure 4 depicts pulse width
variation versus ambient temperature.
6. The ‘‘K’’ coefficient is not a constant, but varies as a
function of the timing capacitor CX. Figure 5 details this
characteristic.
TL/F/6538 – 6
FIGURE 5
7. Under any operating condition CX and RX must be kept
as close to the one-shot device pins as possible to minimize stray capacitance, to reduce noise pick-up, and to
reduce I c R and Ldi/dt voltage developed along their
connecting paths. If the lead length from CX to pins (10)
and (11) is greater than 3 cm, for example, the output
pulse width might be quite different from values predicted
from the appropriate equations. A non-inductive and low
capacitive path is necessary to ensure complete discharge of CX in each cycle of its operation so that the
output pulse width will be accurate.
8. VCC and ground wiring should conform to good high-frequency standards and practices so that switching transients on the VCC and ground return leads do not cause
interaction between one-shots. A 0.01 mF to 0.10 mF bypass capacitor (disk ceramic or monolithic type) from VCC
to ground is necessary on each device. Furthermore, the
bypass capacitor should be located as close to the VCCpin as space permits.
TL/F/6538 – 4
FIGURE 3
TL/F/6538 – 5
FIGURE 4
For further detailed device characteristics and output performance please
refer to the NSC one-shot application note, AN-366.
4
Physical Dimensions inches (millimeters)
14-Lead Ceramic Dual-In-Line Package (J)
Order Number 54121DMQB or DM54121J
NS Package Number J14A
14-Lead Molded Dual-In-Line Package (N)
Order Number DM74121N
NS Package Number N14A
5
54121/DM54121/DM74121 One-Shot with Clear and Complementary Outputs
Physical Dimensions inches (millimeters) (Continued)
14-Lead Ceramic Flat Package (W)
Order Number 54121FMQB or DM54121W
NS Package Number W14B
LIFE SUPPORT POLICY
NATIONAL’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 NATIONAL
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 whose
failure to perform, when properly used in accordance
with instructions for use provided in the labeling, can
be reasonably expected to result in a significant injury
to the user.
National Semiconductor
Corporation
1111 West Bardin Road
Arlington, TX 76017
Tel: 1(800) 272-9959
Fax: 1(800) 737-7018
2. A critical component is any component of a life
support device or system whose failure to perform can
be reasonably expected to cause the failure of the life
support device or system, or to affect its safety or
effectiveness.
National Semiconductor
Europe
Fax: (a49) 0-180-530 85 86
Email: cnjwge @ tevm2.nsc.com
Deutsch Tel: (a49) 0-180-530 85 85
English Tel: (a49) 0-180-532 78 32
Fran3ais Tel: (a49) 0-180-532 93 58
Italiano Tel: (a49) 0-180-534 16 80
National Semiconductor
Hong Kong Ltd.
13th Floor, Straight Block,
Ocean Centre, 5 Canton Rd.
Tsimshatsui, Kowloon
Hong Kong
Tel: (852) 2737-1600
Fax: (852) 2736-9960
National Semiconductor
Japan Ltd.
Tel: 81-043-299-2309
Fax: 81-043-299-2408
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications.
Similar pages