54121 DM54121 DM74121 One-Shot with Clear and Complementary Outputs June 1989 54121 DM54121 DM74121 One-Shot with Clear and Complementary Outputs General Description The DM54 74121 is a monostable multivibrator featuring both positive and negative edge triggering with complementary outputs An internal 2kX timing resistor is provided for design convenience minimizing component count and layout problems This device can be used with a single external capacitor Inputs (A) are active-low trigger transition inputs and input (B) is an active-high transition Schmitt-trigger input that allows jitter-free triggering from inputs with transition rates as slow as 1 volt second A high immunity to VCC noise of typically 1 5V is also provided by internal circuitry at the input stage To obtain optimum and trouble free operation please read operating rules and NSC one-shot application notes carefully and observe recommendations Y Y Y Y Y Y Y Jitter free Schmitt-trigger input Excellent noise immunity typically 1 2V Stable pulse width up to 90% duty cycle TTL DTL compatible Compensated for VCC and temperature variations Input clamp diodes Alternate Military Aerospace device (54121) is available Contact a National Semiconductor Sales Office Distributor for specifications Functional Description The basic output pulse width is determined by selection of an internal resistor RINT or an external resistor (RX) and capacitor (CX) Once triggered the output pulse width is independent of further transitions of the inputs and is a function of the timing components Pulse width can vary from a few nano-seconds to 28 seconds by choosing appropriate RX and CX combinations There are three trigger inputs from the device two negative edge-triggering (A) inputs one positive edge Schmitt-triggering (B) input Features Y Y Triggered from active-high transition or active-low transition inputs Variable pulse width from 30 ns to 28 seconds Connection Diagram Dual-In-Line Package Function Table Inputs A1 L X X H H A2 X L X H B H H L X H H H Q L L L L Outputs Q H H H H v H v v L X H L X TL F 6538 - 1 v X L u u e High Logic Level e Low Logic Level e Can Be Either Low or High e Positive Going Transition e Negative Going Transition e A Positive Pulse e A Negative Pulse u v Order Number 54121DMQB 54121FMQB DM54121J DM54121W or DM74121N See NS Package Number J14A N14A or W14B C1995 National Semiconductor Corporation TL F 6538 RRD-B30M105 Printed in U S A Absolute Maximum Ratings (Note) If Military Aerospace specified devices are required please contact the National Semiconductor Sales Office Distributors for availability and specifications Supply Voltage 7V Input Voltage 5 5V Operating Free Air Temperature Range b 55 C to a 125 C DM54 DM74 0 C to a 70 C Storage Temperature Range b 65 C to a 150 C Note The ``Absolute Maximum Ratings'' are those values beyond which the safety of the device cannot be guaranteed The device should not be operated at these limits The parametric values defined in the ``Electrical Characteristics'' table are not guaranteed at the absolute maximum ratings The ``Recommended Operating Conditions'' table will define the conditions for actual device operation Recommended Operating Conditions Symbol VCC VT a VTb VT a VTb IOH IOL tW dV dt dV dt REXT CEXT DC TA Supply Voltage Positive-Going Input Threshold Voltage at the A Input (VCC e Min) Negative-Going Input Threshold Voltage at the A Input (VCC e Min) Positive-Going Input Threshold Voltage at the B Input (VCC e Min) Negative-Going Input Threshold Voltage at the B Input (VCC e Min) High Level Output Current Low Level Output Current Input Pulse Width (Note 1) Rate of Rise or Fall of Schmidt Input (B) (Note 1) Rate of Rise or Fall of Logic Input (A) (Note 1) External Timing Resistor (Note 1) External Timing Capacitance (Note 1) Duty Cycle (Note 1) RT e 2 kX RT e REXT (Max) Free Air Operating Temperature b 55 Note 1 TA e 25 C and VCC e 5V Parameter Min 45 DM54121 Nom 5 14 08 14 15 08 13 b0 4 DM74121 Max 55 2 08 2 08 Min 4 75 Nom 5 14 14 15 13 b0 4 Units Max 5 25 2 V V V 2 V V mA mA ns 1 1 Vs V ms kX mF % C 16 40 1 1 14 0 30 1000 67 90 125 0 14 0 40 16 40 1000 67 90 70 Electrical Characteristics over recommended operating free air temperature range (unless otherwise noted) Symbol VI VOH VOL II IIH IIL IOS ICC Parameter Input Clamp Voltage High Level Output Voltage Low Level Output Voltage Input Current Input Voltage Max Conditions VCC e Min VCC e Min VIL e Max II e b12 mA IOH e Max VIH e Min 24 34 02 04 1 40 80 b1 6 b3 2 b 20 b 18 b 55 b 55 Min Typ (Note 1) Max b1 5 Units V V V mA mA mA mA mA VCC e Min IOL e Max VIH e Min VIL e Max VCC e Max VI e 5 5V VCC e Max VI e 2 4V VCC e Max VI e 0 4V VCC e Max (Note 2) VCC e Max A1 A2 B A1 A2 B DM54 DM74 Quiescent Triggered High Level Input Current Low Level Input Current Short Circuit Output Current Supply Current 13 23 25 40 Note 1 All typicals are at VCC e 5V TA e 25 C Note 2 Not more than one output should be shorted at a time 2 Switching Characteristics Symbol tPLH tPLH tPHL tPHL tW(OUT) Parameter Propagation Delay Time Low to High Level Output Propagation Delay Time Low to High Level Output Propagation Delay Time High to Low Level Output Propagation Delay Time High to Low Level Output Output Pulse Width Using the Internal Timing Resistor Output Pulse Width Using Zero Timing Capacitance Output Pulse Width Using External Timing Resistor at VCC e 5V and TA e 25 C (See Section 1 for Test Waveforms and Outout Load) From (Input) To (Output) A1 A2 to Q B to Q A1 A2 to Q B to Q A1 A2 or B to Q Q CEXT e 80 pF RINT to VCC RL e 400X CL e 15 pF CEXT e 0 pF RINT to VCC RL e 400X CL e 15 pF CEXT e 100 pF RINT e 10 kX RL e 400X CL e 15 pF CEXT e 1 mF RINT e 10 kX RL e 400X CL e 15 pF Conditions CEXT e 80 pF RINT to VCC CL e 15 pF RL e 400X Min Max 70 55 80 65 Units ns ns ns ns 70 150 ns tW(OUT) A1 A2 to Q Q 50 ns tW(OUT) A1 A2 to Q Q 600 800 ns A1 A2 to Q Q 6 8 ms Operating Rules 1 To use the internal 2 kX timing resistor connect the RINT pin to VCC 2 An external resistor (RX) or the internal resistor (2 kX) and an external capacitor (CX) are required for proper operation The value of CX may vary from 0 to any necessary value For small time constants use high-quality mica glass polypropylene polycarbonate or polystyrene capacitors For large time constants use solid tantalum or special aluminum capacitors If the timing capacitors have leakages approaching 100 nA or if stray capacitance from either terminal to ground is greater than 50 pF the timing equations may not represent the pulse width the device generates 3 The pulse width is essentially determined by external timing components RX and CX For CX k 1000 pF see Figure 1 design curves on TW as function of timing components value For CX l1000 pF the output is defined as tW e K RX CX where RX is in Kilo-ohm CX is in pico Farad TW is in nano second K 07 TL F 6538 - 2 FIGURE 1 4 If CX is an electrolytic capacitor a switching diode is often required for standard TTL one-shots to prevent high inverse leakage current (Figure 2) TL F 6538 - 3 FIGURE 2 3 Operating Rules (Continued) 5 Output pulse width versus VCC and operation temperatures Figure 3 depicts the relationship between pulse width variation versus VCC Figure 4 depicts pulse width variation versus ambient temperature 6 The ``K'' coefficient is not a constant but varies as a function of the timing capacitor CX Figure 5 details this characteristic TL F 6538 - 6 TL F 6538 - 4 FIGURE 3 TL F 6538 - 5 FIGURE 4 FIGURE 5 7 Under any operating condition CX and RX must be kept as close to the one-shot device pins as possible to minimize stray capacitance to reduce noise pick-up and to reduce I c R and Ldi dt voltage developed along their connecting paths If the lead length from CX to pins (10) and (11) is greater than 3 cm for example the output pulse width might be quite different from values predicted from the appropriate equations A non-inductive and low capacitive path is necessary to ensure complete discharge of CX in each cycle of its operation so that the output pulse width will be accurate 8 VCC and ground wiring should conform to good high-frequency standards and practices so that switching transients on the VCC and ground return leads do not cause interaction between one-shots A 0 01 mF to 0 10 mF bypass capacitor (disk ceramic or monolithic type) from VCC to ground is necessary on each device Furthermore the bypass capacitor should be located as close to the VCCpin as space permits For further detailed device characteristics and output performance please refer to the NSC one-shot application note AN-366 4 Physical Dimensions inches (millimeters) 14-Lead Ceramic Dual-In-Line Package (J) Order Number 54121DMQB or DM54121J NS Package Number J14A 14-Lead Molded Dual-In-Line Package (N) Order Number DM74121N NS Package Number N14A 5 54121 DM54121 DM74121 One-Shot with Clear and Complementary Outputs Physical Dimensions inches (millimeters) (Continued) 14-Lead Ceramic Flat Package (W) Order Number 54121FMQB or DM54121W NS Package Number W14B LIFE SUPPORT POLICY NATIONAL'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF NATIONAL SEMICONDUCTOR CORPORATION As used herein 1 Life support devices or systems are devices or systems which (a) are intended for surgical implant into the body or (b) support or sustain life and whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected to result in a significant injury to the user National Semiconductor Corporation 1111 West Bardin Road Arlington TX 76017 Tel 1(800) 272-9959 Fax 1(800) 737-7018 2 A critical component is any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness National Semiconductor Europe Fax (a49) 0-180-530 85 86 Email cnjwge tevm2 nsc com Deutsch Tel (a49) 0-180-530 85 85 English Tel (a49) 0-180-532 78 32 Fran ais Tel (a49) 0-180-532 93 58 Italiano Tel (a49) 0-180-534 16 80 National Semiconductor Hong Kong Ltd 13th Floor Straight Block Ocean Centre 5 Canton Rd Tsimshatsui Kowloon Hong Kong Tel (852) 2737-1600 Fax (852) 2736-9960 National Semiconductor Japan Ltd Tel 81-043-299-2309 Fax 81-043-299-2408 National does not assume any responsibility for use of any circuitry described no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications