54123

54123 NSC | Alldatasheet

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N " A National 54123/DM74123 Dual Retriggerable One-Shot with Clear and Complementary Outputs General Description Features The '123 is a dual retriggerable monostable multivibrator ™ DC triggered from active-high transition or active-low capable of generating output pulses from a few nano-sec- transition inputs onds to extremely long duration up to 100% duty cycle. Retriggerable to 100% duty cycle Each device has three inputs permitting the choice of either = Direct reset terminates output pulse leading-edge or trailing edge triggering. Pin (A) is an active- Compensated for Voc and temperature variations low transition trigger input and pin (B) is an active-high tran- gy DTL, TTL compatible sition trigger input. The clear (CLA) input terminates the out- i, ut clamp diodes put pulse at a predetermined time independent of the timing Pt p components. eae National's '123 device features a unique logic realization not Functional Description . . implemented by other manufacturers, The “Clear” input will The basic output pulse width is determined by selection of not trigger the device, a design tailored for applications 4" @xternal resistor (Rx) and capacitor (Cx). Once triggered, where it shall only terminate or reduce a timing pulse. the basic pulse width may be extended by retriggering the To obtain the be: d ble fr tion ft this d gated active-low transition or active-high transition inputs or [0 obtain st and trouble tree operation from this de- he reduced by use of the active-low transition clear input. vice please read the operating rules as well as the NSC. Retriggering to 100% duty cycle is possible by application of one shot application notes carefully and observe recom- an input pulse train whose cycle time is shorter than the mendations. output cycle time such that a continuous “HIGH” logic state is maintained at the “Q” output. Connection Diagram Dual-in-Line Package Triggering Truth Table ton! [pas | 7 1 a Response cc Cer Set Qt a CLR 2 82 a2 16 15 14 13 12 "1 10 9 x x L_ | No Trigger Nb x | No Trigger | NOH H_ | Trigger Q H 7 — X | NoTrigger Det) CE] | 0 | irom cur o L H ~__| Trigger T H = HIGH Voltage Level L = LOW Voltage Level X = Immaterial 1 2 3 4 5 6 7 8 ry BI Rt a az Con 2 Re 2 ND Cor TLIF/6539—1 Order Number 54123DMGB, 54123FMQB or DM74123N See NS Package Number J16A, N16A or W16A 4-124

N Absolute Maximum Ratings (note) ° It Military/Aerospace specified devices are required, Note: The “Absolute Maximum Ratings” are those values please contact the National Semiconductor Sales beyond which the safety of the device cannot be guaran- Office/Distributors for availability and specifications. teed. The device should not be operated at these limits. The Supply Voltage ~v parametric values defined in the "Electrical Characteristics” Input Voltage 5.5V table are not guaranteed at the absolute maximum ratings. nput Voltage : The “Recommended Operating Conditions” table will define Operating Free Air Temperature Range the conditions for actual device operation. 54 —55°C to + 125°C DM74 OC to +70°C Storage Temperature —65°C to + 150°C Recommended Operating Conditions “met me ee “ Voc___|_ Supply Voltage Pas [os [ss [ars [os [sa [ v tout High Level Output Current [ff oe PT 08 [ma (note) TAowtw | | |. [||] os | Geartow [TT to fT Twa Minimum Width of AorB ns (Min) Pulse at Q (Note 5) Rext__| External Timing Resistor a Cexr__| External Timing Capacitance Po Ne Restriction | uF CwirE Wiring Capacitance F at Rext/Cext Terminal (Note 5) e Ta Free Ait Operating Temperature [ss] f vs To [| |e

Electrical Characteristics

over recommended operating free air temperature range (unless otherwise noted) Typ vi Input Clamp Vottage | Veo=Minnn=-12ma TT ts |v Vou High Level Ouput Voo=Min.ion=Max | 54 | 24 | y otege Vi =MexVn=Min | om7a | 25 | Vou Low Level Output Veo = Min, Io. = Max v Voltage Vin = Min, Vi, = Max I Input Current @ Max Voc = Max, V; = 5.5V 1 mA Input Voltage tm High Level Input Voo = Max [daa | | ft oy ae ee le los Short Circuit Voo = Max [sa [ -0 | T -40 loc Supply Current Voc = Max (Notes 3 and 4) [ [| «4 [ 6 | m Nate 1: All typicals are at Voc = 5V, Ta = 25°C. Note 2: Not more than one output should be shorted at a time. Note 3: Quiescent icc is measured (after clearing) with 2.4V applied to all clear and A inputs, B inputs grounded, all outputs open,Cext = 0.02 pF, and Rext = 25 Kn. ‘Note 4: ioc is measured in the triggered state with 2.4V applied to all clear and B inputs, A inputs grounded, all outputs open, Cexr = 0.02 wF, and Rext = 25 k®. Note 5: Ta = 25°C and Vcc = 5V. 4-125

=| Switching Characteristics atvcc = 5v and Ta = 25°C (See Section 1 for Test Waveforms and Output Load) | M4123 From (Input) | ¢, = 15 pF, Ri = 400 = = L pF, RL ny CL = 15pF,R, = 4000 Symbol me To (Output) | op, = opr, Rexr = 5k2 | Cext = 1000 pF, Rexr = 10Ka | Units tei Propagation Delay Time x Low to High Level Output | At ns tPLH Propagation Delay Time Low to High Level Output BtoQ ns teHL Propagation Delay Time ns High to Low Level Output tPHL Propagation Delay Time High to Low Level Output | 812 ns tPLH Propagation Delay Time Low to High Level Output | Clearto 40 ns teHL Propagation Delay Time High to Low Level Output | Tlearto@ a7 a7 ns wow [OutputPusewiatnt | AorBtoa [308 [sve [soa T3768 | “*Cect = 1000 pF, Rexr = 10k Operating Rules 1. An external resistor (Rx) and external capacitor (Cx) are required for proper operation. The value of Cx may vary Ry o PINT from 0 to any necessary value. For smalll time constants Vee ) high-grade mica, glass, polypropylene, polycarbonate, or cy polystyrene material capacitors may be used. For large few P time constants use tantalum or special aluminum capaci- ©) tors. If the timing capacitors have leakages approaching TL/F/6539-3 100 nA or if stray capacitance from either terminal to FIGURE 2 ground is greater than 50 pF the timing equations may 5. For Cx < 1000 pF see Figure 3 for Tw vs Cx family not represent the pulse width the device generates. curves with Rx as a parameter: 2. When an electrolytic capacitor is used for Cx a switching diode is often required for standard TTL one-shots to pre- 108 33 earn vent high inverse leakage current (Figure 2). However, its Pay use in general is not recommended with retriggerable op- w Let Cie eration. St — ey 3. The output pulse width (Tw) for Cx > 1000 pF is defined = . saat Tw = K Rx Cx (1 + 0.7/Rx) eesei. eee whore [Fi in Kio-obr] w rane [Cxis in pio Farad! San [Tw is in nano second] y» CIT Pe) IK © 0.34] 10 100 1000 F 4, The multiplicative factor K is plotted as a function of Cx Serr (oF) below for design considerations: FIGURES TLIF/6539-4 100 pF 6. To obtain variable pulse width by remote trimming, the CMT Tam 25° following circuit is recommended: CIT F re OIE cna =n On ‘OR (15) Sve ATT ce ame | wer PAPTEELET EEE ow 1 . er HAT unvesoe-s 100F CUTE PRT] Note: “Rremote” should be as close to the one-shot as possible. O24 6 8 10121818 FIGURE 4 “K" COEFFICIENT TUF /6599-2 FIGURE 1 4-126