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Details, datasheet, quote on part number:SN54LV123AW
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Datasheet text preview:
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS
SCLS393A APRIL 1998 REVISED DECEMBER 1999
D D D D D D D D D
EPIC TM (Enhanced-Performance Implanted CMOS) Process 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 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) Package Options Include Plastic Small-Outline (D, NS), Shrink Small-Outline (DB), Thin Very Small-Outline (DGV), and Thin Shrink Small-Outline (PW) Packages, Ceramic Flat (W) Packages, Chip Carriers (FK), and DIPs (J)
SN54LV123A . . . J OR W PACKAGE SN74LV123A . . . D, DB, DGV, NS, OR PW PACKAGE (TOP VIEW)
1A 1B 1CLR 1Q 2Q 2Cext 2Rext/Cext GND
1 2 3 4 5 6 7 8
16 15 14 13 12 11 10 9
VCC 1Rext/Cext 1Cext 1Q 2Q 2CLR 2B 2A
SN54LV123A . . . FK PACKAGE (TOP VIEW)
1B 1A NC VCC 1R ext /C ext 1CLR 1Q NC 2Q 2Cext
4 5 6 7 8 3 2 1 20 19 18 17 16 15 14 9 10 11 12 13
description
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.
1Cext 1Q NC 2Q 2CLR
NC No internal connection
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 can also 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.
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. EPIC is a trademark of 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
Copyright © 1999, Texas Instruments Incorporated
· DALLAS, TEXAS 75265
2R ext /Cext GND NC 2A 2B
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SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS
SCLS393A APRIL 1998 REVISED DECEMBER 1999
description (continued)
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. The variance in output pulse duration from device to device typically is less than ±0.5% for given external timing components. An example of this distribution for the 'LV123A is shown in Figure 11. Variations in output pulse width versus supply voltage and temperature are shown in Figure 7. During power up, Q outputs will be in the high state, and Q outputs will be in the low state. The outputs will be glitch free without applying a reset pulse. Pin assignments for these devices are identical to those of the 'AHC123A and 'AHCT123A devices for interchangeability when allowed. The SN54LV123A is characterized for operation over the full military temperature range of 55°C to 125°C. The SN74LV123A is characterized for operation from 40°C to 85°C. For additional application information on multivibrators, see the application report Designing With The SN74AHC123A and SN74AHCT123A, literature number SCLA014.
FUNCTION TABLE (each multivibrator) INPUTS CLR L X X H H A X H X L B X X L H OUTPUTS Q L L L Q H 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.
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POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
SN54LV123A, SN74LV123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS WITH SCHMITT-TRIGGER INPUTS
SCLS393A APRIL 1998 REVISED DECEMBER 1999
logic symbol
1A 1B 1 2 13 1CLR 1Cext 1Rext/Cext 2A 2B 9 10 5 11 2CLR 2Cext 2Rext/Cext 6 7 R CX RX/CX 12 2Q 2Q 3 14 15 R CX RX/CX & 4 1Q 1Q &
This symbol is in accordance with ANSI/IEEE Std 91-1984 and IEC Publication 617-12. Pin numbers shown are for the D, DB, J, N, PW, and W packages.
logic diagram, each multivibrator (positive logic)
Rext/Cext A B CLR Cext Q R Q
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
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