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Details, datasheet, quote on part number:74HCT123N
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| Part: | 74HCT123N |
| Category: | Logic => Multivibrators/Oscillators |
| Description: | 74HC/HCT123; Dual Retriggerable Monostable Multivibrator With Reset;; Package: SOT109-1 (SO16), SOT338-1 (SSOP16), SOT38-4 (DIP16), SOT403-1 (TSSOP16) |
| Company: | Philips Semiconductors |
| Datasheet: | Download 74HCT123N datasheet File size : 113 kB |
| Request For quote: | Find where to buy 74HCT123N
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Datasheet text preview:
INTEGRATED CIRCUITS
DATA SHEET
For a complete data sheet, please also download:
· The IC06 74HC/HCT/HCU/HCMOS Logic Family Specifications · The IC06 74HC/HCT/HCU/HCMOS Logic Package Information · The IC06 74HC/HCT/HCU/HCMOS Logic Package Outlines
74HC/HCT123 Dual retriggerable monostable multivibrator with reset
Product specification Supersedes data of September 1993 File under Integrated Circuits, IC06 1998 Jul 08
Philips Semiconductors
Product specification
Dual retriggerable monostable multivibrator with reset
FEATURES · DC triggered from active HIGH or active LOW inputs · Retriggerable for very long pulses up to 100% duty factor · Direct reset terminates output pulse · Schmitt-trigger action on all inputs except for the reset input · Output capability: standard (except for nREXT/CEXT) · ICC category: MSI GENERAL DESCRIPTION The 74HC/HCT123 are high-speed Si-gate CMOS devices and are pin compatible with low power Schottky TTL (LSTTL). They are specified in compliance with JEDEC standard no. 7A. The 74HC/HCT123 are dual retriggerable monostable multivibrators with output pulse width control by three methods. The basic pulse time is programmed by selection of an external resistor (REXT) and capacitor (CEXT). The external resistor and capacitor are normally connected as shown in Fig.6. 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 nRD, which also inhibits the triggering. An internal connection from nRD to the input gates makes it possible to trigger the circuit by a positive-going signal at input nRD as shown in the function table. Figures 7 and 8 illustrate pulse control by retriggering 1998 Jul 08 2 QUICK REFERENCE DATA GND = 0 V; Tamb = 25 °C; tr = tf = 6 ns and early reset. The basic output pulse width is essentially determined by the values of the external timing components REXT and CEXT. For pulse widths, when CEXT 10 000 pF, the typical output pulse width is defined as: tW = 0.45 × REXT × CEXT (typ.),
74HC/HCT123
where: tW = pulse width in ns; REXT = external resistor in k; CEXT = external capacitor in pF. Schmitt-trigger action in the nA and nB inputs, makes the circuit highly tolerant to slower input rise and fall times. The `123' is identical to the `423' but can be triggered via the reset input.
TYPICAL SYMBOL tPHL/ tPLH PARAMETER propagation delay nA, nB to nQ, nQ nRD to nQ, nQ CI CPD input capacitance power dissipation capacitance per monostable notes 1 and 2 CONDITIONS HC CL = 15 pF; VCC = 5 V; REXT = 5 k; CEXT = 0 pF 26 20 3.5 54 HCT 26 23 3.5 56 ns ns pF pF UNIT
Notes 1. CPD is used to determine the dynamic power dissipation (PD in µW): PD = CPD × VCC2 × fi + (CL × VCC2 × fo) + 0.75 × CEXT × VCC2 × fo + D × 16 × VCC where: fi = input frequency in MHz fo = output frequency in MHz D = duty factor in % CL = output load capacitance in pF VCC = supply voltage in V CEXT = timing capacitance in pF (CL × VCC2 × fo) sum of outputs 2. For HC the condition is VI = GND to VCC For HCT the condition is VI = GND to VCC - 1.5 V
Philips Semiconductors
Product specification
Dual retriggerable monostable multivibrator with reset
ORDERING INFORMATION TYPE NUMBER 74HC123N; 74HCT123N 74HC123D; 74HCT123D 74HC123DB; 74HCT123DB 74HC123PW; 74HCT123PW PACKAGE NAME DIP16 SO16 SSOP16 TSSOP16 DESCRIPTION plastic dual in-line package; 16 leads (300 mil); long body plastic small outline package; 16 leads; body width 3.9 mm
74HC/HCT123
VERSION SOT38-1 SOT109-1 SOT338-1 SOT403-1
plastic shrink small outline package; 16 leads; body width 5.3 mm plastic thin shrink small outline package; 16 leads; body width 4.4 mm
PIN DESCRIPTION PIN NO. 1, 9 2, 10 3, 11 4, 12 7 8 13, 5 14, 6 15 16 1A, 2A 1B, 2B 1RD, 2RD 1Q, 2Q 2REXT/CEXT GND 1Q, 2Q 1CEXT, 2CEXT 1REXT/CEXT VCC SYMBOL NAME AND FUNCTION trigger inputs (negative-edge triggered) trigger inputs (positive-edge triggered) direct reset LOW and trigger action at positive edge outputs (active LOW) external resistor/capacitor connection ground (0 V) outputs (active HIGH) external capacitor connection external resistor/capacitor connection positive supply voltage
Fig.1 Pin configuration.
Fig.2 Logic symbol.
Fig.3 IEC logic symbol.
1998 Jul 08
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Philips Semiconductors
Product specification
Dual retriggerable monostable multivibrator with reset
FUNCTION TABLE INPUTS nRD L X X H H Note 1. If the monostable was triggered before this condition was established, the pulse will continue as programmed. nA X H X L L nB X X L H H L L(1) L(1) OUTPUTS nQ nQ H H(1) H(1) H L X
74HC/HCT123
= HIGH voltage level = LOW voltage level = don't care = LOW-to-HIGH transition = HIGH-to-LOW transition = one HIGH level output pulse = one LOW level output pulse
Fig.4 Functional diagram.
(1) For minimum noise generation, it is recommended to ground pins 6 (2CEXT) and 14 (1CEXT) externally to pin 8 (GND).
Fig.5 Logic diagram.
1998 Jul 08
4
Philips Semiconductors
Product specification
Dual retriggerable monostable multivibrator with reset
74HC/HCT123
Fig.6 Timing component connections.
DC CHARACTERISTICS FOR 74HC For the DC characteristics see "74HC/HCT/HCU/HCMOS Logic Family Specifications". Output capability: standard (except for nREXT/CEXT) ICC category: MSI
1998 Jul 08
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