datasheets 74121 free download

File name 74121.pdf

54121 DM54121 DM74121 One-Shot with Clear and Complementary Outputs June 1989 54121 DM54121 DM74121 One-Shot with Clear and Complementary Outputs Y Jitter free Schmitt-trigger input General Description Y Excellent noise immunity typically 1 2V The DM54 74121 is a monostable multivibrator featuring Y Stable pulse width up to 90% duty cycle both positive and negative edge triggering with complemen- tary outputs An internal 2kX timing resistor is provided for Y TTL DTL compatible design convenience minimizing component count and lay- Y Compensated for VCC and temperature variations out problems This device can be used with a single external Y Input clamp diodes capacitor Inputs (A) are active-low trigger transition inputs Y Alternate Military Aerospace device (54121) is avail- and input (B) is an active-high transition Schmitt-trigger in- able Contact a National Semiconductor Sales Office put that allows jitter-free triggering from inputs with tran- Distributor for specifications sition rates as slow as 1 volt second A high immunity to VCC noise of typically 1 5V is also provided by internal cir- Functional Description cuitry at the input stage The basic output pulse width is determined by selection of To obtain optimum and trouble free operation please read an internal resistor RINT or an external resistor (RX) and operating rules and NSC one-shot application notes careful- capacitor (CX) Once triggered the output pulse width is in- ly and observe recommendations dependent of further transitions of the inputs and is a func- tion of the timing components Pulse width can vary from a Features few nano-seconds to 28 seconds by choosing appropriate Y Triggered from active-high transition or active-low tran- RX and CX combinations There are three trigger inputs from sition inputs the device two negative edge-triggering (A) inputs one pos- Y Variable pulse width from 30 ns to 28 seconds itive edge Schmitt-triggering (B) input Connection Diagram Function Table Inputs Outputs Dual-In-Line Pack