SN74LVC1G123

• Available in the Texas Instruments
  NanoFree™ Package
• Supports 5-V V_CC Operation
• Inputs Accept Voltages to 5.5 V
• Max t_pd of 8 ns at 3.3 V
• Supports Mixed-Mode Voltage Operation on
  All Ports
• Supports Down Translation to V_CC
• Schmitt-Trigger Circuitry on A and B Inputs for
  Slow Input Transition Rates
• Edge Triggered From Active-High or Active-Low
   Gated Logic Inputs
• Retriggerable for Very Long Output Pulses, Up to
  100% Duty Cycle
• Overriding Clear Terminates Output Pulse
• Glitch-Free Power-Up Reset on Outputs
• I_off Supports Live Insertion, Partial-Power-Down
  Mode, and Back-Drive Protection
• Latch-Up Performance Exceeds 100 mA Per
  JESD 78, Class II
• ESD Protection Exceeds JESD 22
  • 2000-V Human-Body Model (A114-A)
  • 200-V Machine Model (A115-A)
  • 1000-V Charged-Device Model (C101)

The SN74LVC1G123 device is a single retriggerable monostable multivibrator designed for 1.65-V to 5.5-V V_CC operation.

This monostable multivibrator features output pulse-duration control by three methods. In the first method, the A input is low, and the B input goes high. In the second method, the B input is high, and the A input goes low. In the third method, the A input is low, the B input is high, and the clear (CLR) input goes high.

The output pulse duration is programmed by selecting external resistance and capacitance values. The external timing capacitor must be connected between C_ext and R_ext/C_ext (positive) and an external resistor connected between R_ext/C_ext and V_CC. To obtain variable pulse durations, connect an external variable resistance between R_ext/C_ext and V_CC. The output pulse duration also can be reduced by taking CLR low.

Pulse triggering occurs at a particular voltage level and is not directly related to the transition time of the input pulse. The A and B inputs have Schmitt triggers with sufficient hysteresis to handle slow input transition rates with jitter-free triggering at the outputs.