The LMC555 is a CMOS version of the industry standard 555 series general purpose timers. In addition to the standard package (SOIC, MSOP, and MDIP) the LMC555 is also available in a chip sized package (8 Bump micro SMD) using National's micro SMD package technology.
The LMC555 offers the same capability of generating accurate time delays and frequencies as the
LM555 but with much lower power dissipation and supply current spikes. When operated as a one-shot, the time delay is precisely controlled by a single external resistor and capacitor. In the stable mode the oscillation frequency and duty cycle are accurately set by two external resistors and one capacitor. The use of National Semiconductor's LMCMOS™ process extends both the frequency range and low supply capability
In this mode of operation, the timer functions as a one-shot. The external capacitor is initially held discharged by internal circuitry. Upon application of a negative trigger pulse of less than 1/3 VS to the Trigger terminal, the flip-flop is set which both releases the short circuit across the capacitor and drives the output high.
circuit so long as the trigger input is returned high at least 10μs before the end of the timing interval. However the circuit can be reset during this time by the application of a negative pulse to the reset terminal. The output will then remain in the low state until a trigger pulse is again applied. When the reset function is not use, it is recommended that it be connected to V+ to avoid any possibility of false triggering.