Noise removal circuit

Abstract

A noise removal circuit. The noise removal circuit comprises a crystal oscillator and a level decision module. The crystal oscillator generates an oscillating signal and an output clock signal. The level decision module detects the signal level of the oscillating signal and outputs the output clock signal when the signal level of the oscillating signal exceeds a first reference level.

1 . A noise removal circuit comprising:
 a crystal oscillator generating an oscillating signal and an output clock signal; and   a timing circuit coupled to the crystal oscillator, receiving the oscillating signal and outputting the output clock signal after a predetermined interval, wherein the timing circuit further comprises a gating logic outputting the output clock signal in response to an enable signal, and wherein the gating logic comprises a logic gate receiving the output clock signal and the enable signal, and a second inverter coupled to the output of the logic gate, outputting the output clock signal.   
   
   
       2 . The noise removal circuit as claimed in  claim 1 , wherein the crystal oscillator comprises a first inverter amplifying the oscillating signal to generate the output clock signal. 
   
   
       3 . The noise removal circuit as claimed in  claim 1 , wherein the timing circuit comprises a counter receiving the oscillating signal for triggering a counting operation thereof and generating the enable signal after the predetermined interval. 
   
   
       4 . The noise removal circuit as claimed in  claim 1 , wherein the logic gate comprises an NAND gate.