54121

Features:

* Triggered from active-high transition or active-low transition
   inputs
* Variable pulse width from 30 ns to 28 seconds
* 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.


Pinout




Specifications

Supply Voltage                                                    7V
Input Voltage                                                   5.5V
Operating Free Air Temperature Range
DM54                                              -55 to +125
DM74                                                    0 to +70
Storage Temperature Range           -65 to +150


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) of DM54/74121 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 about DM54/74121.