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Details, datasheet, quote on part number:SN74AHC123ADB
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Datasheet text preview:
SN54AHC123A, SN74AHC123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS
SCLS352E JULY 1997 REVISED JANUARY 2000
D D D D D D D D D D
EPIC TM (Enhanced-Performance Implanted CMOS) Process Operating Range 2-V to 5.5-V VCC 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 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), Shrink Small-Outline (DB), Thin Very Small-Outline (DGV), Thin Shrink Small-Outline (PW), and Ceramic Flat (W) Packages, Ceramic Chip Carriers (FK), and Standard Plastic (N) and Ceramic (J) DIPs
SN54AHC123A . . . J OR W PACKAGE SN74AHC123A . . . D, DB, DGV, N, 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
SN54AHC123A . . . 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
1Cext 1Q NC 2Q 2CLR
The 'AHC123A 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 programmed 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. CLR input can be used to override A or B inputs. 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. EPIC is a trademark of Texas Instruments Incorporated.
PRODUCTION DATA information is 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.
NC No internal connection
Copyright © 2000, Texas Instruments Incorporated
On products compliant to MIL-PRF-38535, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters.
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
2R ext /Cext GND NC 2A 2B
description
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SN54AHC123A, SN74AHC123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS
SCLS352E JULY 1997 REVISED JANUARY 2000
description (continued)
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 'AHC123A is shown in Figure 10. Variations in output pulse duration versus supply voltage and temperature are shown in Figure 6. During power up, Q outputs are in the high state, and Q outputs are in the low state. The outputs are glitch free without applying a reset pulse. The SN54AHC123A is characterized for operation over the full military temperature range of 55°C to 125°C. The SN74AHC123A 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 H OUTPUTS Q L L L Q H H H
#
L
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.
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, DGV, J, N, PW, and W packages.
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POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
SN54AHC123A, SN74AHC123A DUAL RETRIGGERABLE MONOSTABLE MULTIVIBRATORS
SCLS352E JULY 1997 REVISED JANUARY 2000
logic diagram, each multivibrator (positive logic)
Rext/Cext A B CLR Cext Q R Q
input/output timing diagram
tr r A
B
CLR
Rext/Cext
Q
Q tw tw tw + t r r
POST OFFICE BOX 655303
· DALLAS, TEXAS 75265
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