TI SN74LV123ADBR
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SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
1
16
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VCC 1Rext/Cext 1Cext 1Q 2Q 2CLR 2B 2A
1B 1CLR 1Q 2Q 2Cext 2Rext/Cext
1
16 15 1Rext/Cext 14 1Cext
2 3
13 1Q 12 2Q
4 5
11 2CLR 10 2B
6 7 8
9
SN54LV123A . . . FK PACKAGE (TOP VIEW)
1CLR 1Q NC 2Q 2Cext
4
3 2 1 20 19 18
5
17
6
16
7
15
8
14 9 10 11 12 13
1Cext 1Q NC 2Q 2CLR
2R ext /Cext GND NC 2A 2B
1A 1B 1CLR 1Q 2Q 2Cext 2Rext/Cext GND
Operation Retriggerable for Very Long Output Pulses, up to 100% Duty Cycle Overriding Clear Terminates Output Pulse Glitch-Free Power-Up Reset on Outputs Latch-Up Performance Exceeds 100 mA Per JESD 78, Class II ESD Protection Exceeds JESD 22 − 2000-V Human-Body Model (A114-A) − 200-V Machine Model (A115-A) − 1000-V Charged-Device Model (C101)
SN74LV123A . . . RGY PACKAGE (TOP VIEW)
SN54LV123A . . . J OR W PACKAGE SN74LV123A . . . D, DB, DGV, NS, OR PW PACKAGE (TOP VIEW)
VCC
D
D
2A
D
D D D
1A
D
D
2.3 V at VCC = 3.3 V, TA = 25°C Support Mixed-Mode Voltage Operation on All Ports Schmitt-Trigger Circuitry on A, B, and CLR Inputs for Slow Input Transition Rates Edge Triggered From Active-High or Active-Low Gated Logic Inputs
GND
D
D Ioff Supports Partial-Power-Down Mode
1B 1A NC VCC 1R ext /C ext
D 2-V to 5.5-V VCC Operation D Max tpd of 11 ns at 5 V D Typical VOLP (Output Ground Bounce)
NC − No internal connection
description/ordering information The ’LV123A devices are dual retriggerable monostable multivibrators designed for 2-V to 5.5-V VCC operation. These edge-triggered multivibrators feature output pulse-duration control by three methods. In the first method, the A input is low and the B input goes high. In the second method, the B input is high and the A input goes low. In the third method, the A input is low, the B input is high, and the clear (CLR) input goes high. The output pulse duration is programmable by selecting external resistance and capacitance values. The external timing capacitor must be connected between Cext and Rext/Cext (positive) and an external resistor connected between Rext/Cext and VCC. To obtain variable pulse durations, connect an external variable resistance between Rext/Cext and VCC. The output pulse duration also can be reduced by taking CLR low. Pulse triggering occurs at a particular voltage level and is not directly related to the transition time of the input pulse. The A, B, and CLR inputs have Schmitt triggers with sufficient hysteresis to handle slow input transition rates with jitter-free triggering at the outputs. Once triggered, the basic pulse duration can be extended by retriggering the gated low-level-active (A) or high-level-active (B) input. Pulse duration can be reduced by taking CLR low. The input/output timing diagram illustrates pulse control by retriggering the inputs and early clearing. Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet. Copyright © 2005, Texas Instruments Incorporated
UNLESS OTHERWISE NOTED this document contains PRODUCTION DATA information current as of publication date. Products conform to specifications per the terms of Texas Instruments standard warranty. Production processing does not necessarily include testing of all parameters. POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
1
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
description/ordering information (continued) During power up, Q outputs are in the low state, and Q outputs are in the high state. The outputs are glitch free, without applying a reset pulse. These devices are fully specified for partial-power-down applications using Ioff. The Ioff circuitry disables the outputs, preventing damaging current backflow through the devices when they are powered down. Pin assignments for these devices are identical to those of the ’AHC123A and ’AHCT123A devices for interchangeability, when allowed. ORDERING INFORMATION
QFN − RGY
SN74LV123ARGYR
Tube of 40
SN74LV123AD
Reel of 2500
SN74LV123ADR
SOP − NS
Reel of 2000
SN74LV123ANSR
74LV123A
SSOP − DB
Reel of 2000
SN74LV123ADBR
LV123A
Tube of 90
SN74LV123APW
Reel of 2000
SN74LV123APWR
Reel of 250
SN74LV123APWT
TVSOP − DGV
Reel of 2000
SN74LV123ADGVR
LV123A
CDIP − J
Tube of 25
SNJ54LV123AJ
SNJ54LV123AJ
CFP − W
Tube of 150
SNJ54LV123AW
SNJ54LV123AW
LCCC − FK
Tube of 55
SNJ54LV123AFK
SNJ54LV123AFK
TSSOP − PW
−55°C 55 C to 125 125°C C †
LV123A LV123A
LV123A
Package drawings, standard packing quantities, thermal data, symbolization, and PCB design guidelines are available at www.ti.com/sc/package. FUNCTION TABLE (each multivibrator) INPUTS
‡
OUTPUTS
CLR
A
B
Q
Q
L
X
X
L
H
X
L‡
H‡
L‡
H‡
X
2
TOP-SIDE MARKING
Reel of 1000
SOIC − D
−40°C 40 C to 85°C 85 C
ORDERABLE PART NUMBER
PACKAGE†
TA
H
X
X
L
H
L
↑
H
↓
H
↑
L
H
These outputs are based on the assumption that the indicated steady-state conditions at the A and B inputs have been set up long enough to complete any pulse started before the setup.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
logic diagram, each multivibrator (positive logic) Rext/Cext A
Cext
B
Q
CLR
R
Q
input/output timing diagram trr A
B
CLR
Rext/Cext
Q
Q tw
tw
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
tw + trr
3
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
absolute maximum ratings over operating free-air temperature (unless otherwise noted)† Supply voltage range, VCC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Input voltage range, VI (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Voltage range applied to any output in the high-impedance or power-off state, VO (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Output voltage range in high or low state, VO (see Notes 1 and 2) . . . . . . . . . . . . . . . . . −0.5 V to VCC + 0.5 V Output voltage range in power-off state, VO (see Note 1) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −0.5 V to 7 V Input clamp current, IIK (VI < 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −20 mA Output clamp current, IOK (VO < 0) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −50 mA Continuous output current, IO (VO = 0 to VCC) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±25 mA Continuous current through VCC or GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . ±50 mA Package thermal impedance, θJA (see Note 3): D package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 73°C/W (see Note 3): DB package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 82°C/W (see Note 3): DGV package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 120°C/W (see Note 3): NS package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64°C/W (see Note 3): PW package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 108°C/W (see Note 4): RGY package . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39°C/W Storage temperature range, Tstg . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . −65°C to 150°C †
Stresses beyond those listed under “absolute maximum ratings” 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. NOTES: 1. The input and output negative-voltage ratings may be exceeded if the input and output current ratings are observed. 2. This value is limited to 5.5 V maximum. 3. The package thermal impedance is calculated in accordance with JESD 51-7. 4. The package thermal impedance is calculated in accordance with JESD 51-5.
4
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
recommended operating conditions (see Note 5) SN54LV123A VCC
Supply voltage VCC = 2 V
VIH
High level input voltage High-level
MIN
MAX
2
5.5
1.5
Low level input voltage Low-level
VI
Input voltage
VO
Output voltage
VCC × 0.7 VCC × 0.7
VCC = 4.5 V to 5.5 V
VCC × 0.7
VCC × 0.7 0.5
External timing resistance
Cext
External timing capacitance
Δt/ΔVCC
Power-up ramp rate
TA
Operating free-air temperature
0.5
VCC × 0.3
VCC × 0.3
VCC = 3 V to 3.6 V
VCC × 0.3
VCC × 0.3
VCC × 0.3 5.5
0
5.5
0
VCC
0
V
VCC
V
−50
−50
μA
−2
−2
VCC = 2.3 V to 2.7 V VCC = 3 V to 3.6 V
−6
−6
−12
−12
50
50
VCC = 2.3 V to 2.7 V
2
2
VCC = 3 V to 3.6 V
6
6
12
12
VCC = 2 V
5k
5k
VCC ≥ 3 V
1k
1k
No restriction
No restriction
1 −55
V
VCC × 0.3
0
VCC = 4.5 V to 5.5 V Rext
V
V
VCC = 2.3 V to 2.7 V
VCC = 2 V Low level output current Low-level
5.5
VCC × 0.7
VCC = 4.5 V to 5.5 V
IOL
2
UNIT
1.5
VCC × 0.7
VCC = 2 V High level output current High-level
MAX
VCC = 2.3 V to 2.7 V
VCC = 4.5 V to 5.5 V
IOH
MIN
VCC = 3 V to 3.6 V VCC = 2 V
VIL
SN74LV123A
−40
μA mA
Ω pF
1 125
mA
ms/V 85
°C
NOTE 5: Unused Rext/Cext terminals should be left unconnected. All remaining unused inputs of the device must be held at VCC or GND to ensure proper device operation. Refer to the TI application report, Implications of Slow or Floating CMOS Inputs, literature number SCBA004.
PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
5
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
electrical characteristics over recommended operating free-air temperature range (unless otherwise noted) SN54LV123A PARAMETER
TEST CONDITIONS
VOH
VCC
Rext/Cext II ICC
ICC
2.3 V
2
2
IOH = −6 mA
3V
2.48
2.48
4.5 V
3.8
TYP
MAX
V
3.8
2 V to 5.5 V
0.1
0.1
IOL = 2 mA
2.3 V
0.4
0.4
IOL = 6 mA
3V
0.44
0.44
4.5 V
0.55
0.55
2 V to 5.5 V
±2.5
±2.5
±1
±1
VI = 5 5.5 5 V or GND
Quiescent
VI = VCC or GND,
IO = 0
VI = VCC or GND, Rext/Cext = 0.5 VCC
0 to 5.5 V
±1
±1
5.5 V
20
20
2.3 V
220
220
3V
280
280
4.5 V
650
650
5.5 V
975
975
VI or VO = 0 to 5.5 V
0
5
3.3 V
1.9
1.9
5V
1.9
1.9
VI = VCC or GND
UNIT
VCC−0.1
IOL = 50 μA
A B, A, B and d CLR
Ci †
VCC−0.1
0
Ioff
MIN
2 V to 5.5 V
VI = 5.5 V or GND
Active state (per circuit)
SN74LV123A MAX
IOH = −2 mA
IOL = 12 mA †
TYP
IOH = −50 μA
IOH = −12 mA
VOL
MIN
V
μA μ μA
μA A
μA pF
This test is performed with the terminal in the off-state condition.
timing requirements over recommended operating free-air temperature range, VCC = 2.5 V ± 0.2 V (unless otherwise noted) (see Figure 1) TEST CONDITIONS
‡
TA = 25°C MIN
TYP
SN54LV123A MAX
MIN
MAX
SN74LV123A MIN
MAX
UNIT
CLR
6
6.5
6.5
A or B trigger
6
6.5
6.5
94
‡
‡
ns
2
‡
‡
ms
tw
Pulse duration
trr
Pulse retrigger time
Rext = 1 kΩ
Cext = 100 pF
‡
Cext = 0.01 mF
‡
ns
See retriggering data in the application information section.
timing requirements over recommended operating free-air temperature range, VCC = 3.3 V ± 0.3 V (unless otherwise noted) (see Figure 1) TEST CONDITIONS
‡
TA = 25°C MIN
TYP
MIN
MAX
SN74LV123A MIN
CLR
5
5
5
A or B trigger
5
5
5
tw
Pulse duration
trr
Pulse retrigger time
Rext = 1 kΩ
MAX
UNIT ns
Cext = 100 pF
‡
76
‡
‡
ns
Cext = 0.01 mF
‡
1.8
‡
‡
ms
See retriggering data in the application information section.
PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice.
6
SN54LV123A MAX
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
timing requirements over recommended operating free-air temperature range, VCC = 5 V ± 0.5 V (unless otherwise noted) (see Figure 1) TEST CONDITIONS
†
TA = 25°C MIN
TYP
SN54LV123A MAX
MIN
MAX
SN74LV123A MIN
MAX
UNIT
CLR
5
5
5
A or B trigger
5
5
5
59
†
†
ns
1.5
†
†
ms
tw
Pulse duration
trr
Pulse retrigger time
Rext = 1 kΩ
Cext = 100 pF
†
Cext = 0.01 mF
†
ns
See retriggering data in the application information section.
switching characteristics over recommended operating VCC = 2.5 V ± 0.2 V (unless otherwise noted) (see Figure 1) PARAMETER
tpd
tpd
FROM (INPUT)
TO (OUTPUT)
A or B
Q or Q
CLR
Q or Q
CLR trigger
TEST CONDITIONS
TA = 25°C MIN
temperature
SN54LV123A MAX
MIN
MAX
MIN
MAX
14.5*
31.4*
1*
37*
1
37
13*
25*
1*
29.5*
1
29.5
Q or Q
15.1*
33.4*
1*
39*
1
39
A or B
Q or Q
16.6
36
1
42
1
42
CLR
Q or Q
14.7
32.8
1
34.5
1
34.5
CLR trigger
Q or Q
17.4
38
1
44
1
44
197
260
CL = 15 pF p
CL = 50 pF p
Q or Q
Δtw§
range,
SN74LV123A
TYP
CL = 50 pF, Cext = 28 pF, Rext = 2 kΩ tw‡
free-air
320
UNIT
ns
ns
320
ns
CL = 50 pF, Cext = 0.01 μF, Rext = 10 kΩ
90
100
110
90
110
90
110
ms
CL = 50 pF, Cext = 0.1 μF, Rext = 10 kΩ
0.9
1
1.1
0.9
1.1
0.9
1.1
ms
±1
CL = 50 pF
%
* On products compliant to MIL-PRF-38535, this parameter is not production tested. ‡ t = Duration of pulse at Q and Q outputs w § Δt = Output pulse-duration variation (Q and Q) between circuits in same package w
PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
7
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
switching characteristics over recommended operating VCC = 3.3 V ± 0.3 V (unless otherwise noted) (see Figure 1) PARAMETER
tpd
tpd
FROM (INPUT)
TO (OUTPUT)
A or B
Q or Q
CLR
Q or Q
CLR trigger
free-air
TA = 25°C
TEST CONDITIONS
MIN
temperature
SN54LV123A
SN74LV123A
TYP
MAX
MIN
MAX
MIN
MAX
10.2*
20.6*
1*
24*
1
24
9.3*
15.8*
1*
18.5*
1
18.5
Q or Q
10.6*
22.4*
1*
26*
1
26
A or B
Q or Q
11.8
24.1
1
27.5
1
27.5
CLR
Q or Q
10.5
19.3
1
22
1
22
CLR trigger
Q or Q
12.3
25.9
1
29.5
1
29.5
182
240
CL = 15 pF p
CL = 50 pF p
CL = 50 pF, Cext = 28 pF, Rext = 2 kΩ tw†
Q or Q
Δtw‡
range,
300
UNIT
ns
ns
300
ns
CL = 50 pF, Cext = 0.01 μF, Rext = 10 kΩ
90
100
110
90
110
90
110
ms
CL = 50 pF, Cext = 0.1 μF, Rext = 10 kΩ
0.9
1
1.1
0.9
1.1
0.9
1.1
ms
±1
CL = 50 pF
%
* On products compliant to MIL-PRF-38535, this parameter is not production tested. † t = Duration of pulse at Q and Q outputs w ‡ Δt = Output pulse-duration variation (Q and Q) between circuits in same package w
switching characteristics over recommended operating VCC = 5 V ± 0.5 V (unless otherwise noted) (see Figure 1) PARAMETER
tpd
tpd
FROM (INPUT)
TO (OUTPUT)
A or B
Q or Q
CLR
Q or Q
CLR trigger
TA = 25°C
TEST CONDITIONS
MIN
SN54LV123A MIN
MAX
MIN
MAX
7.1*
12*
1*
14*
1
14
6.5*
9.4*
1*
11*
1
11
Q or Q
7.4*
12.9*
1*
15*
1
15
A or B
Q or Q
8.3
14
1
16
1
16
CLR
Q or Q
7.4
11.4
1
13
1
13
CLR trigger
Q or Q
8.7
14.9
1
17
1
17
167
200
CL = 15 pF p
CL = 50 pF p
Q or Q
range,
SN74LV123A
MAX
240
UNIT
ns
ns
240
ns
CL = 50 pF, Cext = 0.01 μF, Rext = 10 kΩ
90
100
110
90
110
90
110
ms
CL = 50 pF, Cext = 0.1 μF, Rext = 10 kΩ
0.9
1
1.1
0.9
1.1
0.9
1.1
ms
Δtw‡
±1
* On products compliant to MIL-PRF-38535, this parameter is not production tested. † t = Duration of pulse at Q and Q outputs w ‡ Δt = Output pulse-duration variation (Q and Q) between circuits in same package w
PRODUCT PREVIEW information concerns products in the formative or design phase of development. Characteristic data and other specifications are design goals. Texas Instruments reserves the right to change or discontinue these products without notice.
8
temperature
TYP
CL = 50 pF, Cext = 28 pF, Rext = 2 kΩ tw†
free-air
POST OFFICE BOX 655303
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%
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
operating characteristics, TA = 25°C PARAMETER Cpd
TEST CONDITIONS
Power dissipation capacitance
pF CL = 50 pF,
f = 10 MHz
VCC
TYP
3.3 V
44
5V
49
UNIT pF
PARAMETER MEASUREMENT INFORMATION From Output Under Test
Test Point
tw VCC
CL (see Note A)
Inputs or Outputs
50% VCC
50% VCC 0V
LOAD CIRCUIT
VOLTAGE WAVEFORMS PULSE DURATION VCC
Input A (see Note B)
50% VCC 0V VCC
Input B (see Note B)
50% VCC
50% VCC 0V
50% VCC tPLH
0V tPLH VOH
In-Phase Output
50% VCC
In-Phase Output
VOL VOH 50% VCC VOL
tPHL 50% VCC
tPHL
tPHL Out-of-Phase Output
VCC
Input CLR (see Note B)
Out-of-Phase Output
VOH 50% VCC VOL tPLH
50% VCC
VOH 50% VCC VOL
VOLTAGE WAVEFORMS DELAY TIMES
VOLTAGE WAVEFORMS DELAY TIMES
NOTES: A. CL includes probe and jig capacitance. B. All input pulses are supplied by generators having the following characteristics: PRR ≤ 1 MHz, ZO = 50 Ω, tr + 3 ns, tf + 3 ns. C. The outputs are measured one at a time, with one input transition per measurement.
Figure 1. Load Circuit and Voltage Waveforms
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SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
APPLICATION INFORMATION† OUTPUT PULSE DURATION vs EXTERNAL TIMING CAPACITANCE 1.00E+07
VCC = 3 V TA = 25°C
1.00E+06
t w − Output Pulse Duration − ns
t w − Output Pulse Duration − ns
1.00E+07
OUTPUT PULSE DURATION vs EXTERNAL TIMING CAPACITANCE
RT = 1 MΩ 1.00E+05 RT = 100 kΩ 1.00E+04 RT = 10 kΩ 1.00E+03
VCC = 4.5 V TA = 25°C
1.00E+06 RT = 1 MΩ 1.00E+05 RT = 100 kΩ 1.00E+04 RT = 10 kΩ 1.00E+03
RT = 1 kΩ 1.00E+02 101
RT = 1 kΩ
102
103
104
105
1.00E+02 101
Figure 2
10
103
104
105
CT − External Timing Capacitance − pF
CT − External Timing Capacitance − pF
†
102
Figure 3
Operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
APPLICATION INFORMATION† 1.00E+09 VCC = 5 V TA = 25°C 1.00E+08 RT = 200k Ω
t w − Output Pulse Duration − ns
1.00E+07 RT = 150k Ω
1.00E+06 RT = 80k Ω
1.00E+05
RT = 10k Ω
1.00E+04
RT = 5k Ω
1.00E+03
1.00E+02 RT = 1k Ω 1.00E+01
1.00E+00 1
102
10
103
104
105
106
107
CT − External Timing Capacitance − pF
Figure 4. Output Pulse Duration vs External Timing Capacitance
14%
Variation in Output Pulse Duration
12% 10%
tw = 866 ns at: VCC = 5 V RT = 10 kΩ CT = 50 pF TA = 25°C
VCC = 2.5 V VCC = 3 V VCC = 3.5 V
8%
VCC = 4 V 6%
VCC = 5 V
4%
VCC = 6 V VCC = 7 V
2% 0% −2% −4% −6% −60
−40
−20
0
20
40
60
80
100
120
140
160
180
Temperature − °C
Figure 5. Variations in Output Pulse Duration vs Temperature
†
Operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
11
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
APPLICATION INFORMATION† OUTPUT PULSE-DURATION CONSTANT vs SUPPLY VOLTAGE
MINIMUM TRIGGER TIME vs VCC CHARACTERISTICS 10.00
1.20 Output Pulse-Duration Constant − K
t rr − Minimum Retrigger Time − μs
RT = 1 kΩ TA = 25°C CT = 0.01 μF 1.00
CT = 1000 pF 0.10 CT = 100 pF
0.01
0
1
2
3
4
5
1.15
RT = 10 kΩ TA = 25°C tW = K × C T × R T
1.10 CT = 1000 pF 1.05 CT = 0.01 μF
1.00
0.95
0.90 1.5
6
CT = 0.1 μF
2
2.5 3 3.5 4 4.5 5 VCC − Supply Voltage − V
VCC − Supply Voltage − V
DISTRIBUTION OF UNITS vs OUTPUT PULSE DURATION
CT − External Capacitor Value − μ F
For Capacitor Values of 0.001 μF or Greater, K = 1.0 (K is Independent of R)
0.0001
TA = 25°C VCC = 5 V 0.00001 2.50 3.00 3.50 4.00 4.50
Multiplier Factor − K
Relative Frequency of Occurance
EXTERNAL CAPACITANCE vs MULTIPLIER FACTOR
1.00 1.50 2.00
VCC = 5 V TA = 25°C CT = 50 pF RT = 10 kW
Mean = 856 ns Median = 856 ns Std. Dev. = 3.5 ns
−3 Std. Dev. +3 Std. Dev. Median 99% of Data Units tw − Output Pulse Duration
Figure 8
†
12
6
Figure 7
Figure 6
0.001
5.5
Figure 9
Operation of the device at these or any other conditions beyond those indicated under “recommended operating conditions” is not implied.
POST OFFICE BOX 655303
• DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS SCLS393O − APRIL 1998 − REVISED OCTOBER 2005
APPLICATION INFORMATION caution in use To prevent malfunctions due to noise, connect a high-frequency capacitor between VCC and GND, and keep the wiring between the external components and Cext and Rext/Cext terminals as short as possible.
power-down considerations Large values of Cext can cause problems when powering down the ’LV123A devices because of the amount of energy stored in the capacitor. When a system containing this device is powered down, the capacitor can discharge from VCC through the protection diodes at pin 2 or pin 14. Current through the input protection diodes must be limited to 30 mA; therefore, the turn-off time of the VCC power supply must not be faster than t = VCC × Cext/30 mA. For example, if VCC = 5 V and Cext = 15 pF, the VCC supply must turn off no faster than t = (5 V) × (15 pF)/30 mA = 2.5 ns. Usually, this is not a problem because power supplies are heavily filtered and cannot discharge at this rate. When a more rapid decrease of VCC to zero occurs, the ’LV123A devices can sustain damage. To avoid this possibility, use external clamping diodes.
output pulse duration The output pulse duration, tw, is determined primarily by the values of the external capacitance (CT) and timing resistance (RT). The timing components are connected as shown in Figure 10. VCC
RT
CT
To Rext/Cext Terminal
To Cext Terminal
Figure 10. Timing-Component Connections The pulse duration is given by: tw + K
RT
CT
(1)
if CT is ≥1000 pF, K = 1.0 or if CT is
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