Dave's Circuits:  Astable Oscillator Circuits             Audio Oscillator Circuits             Crystal Oscillators               RF (Radio Frequency) Oscillators         Sine Wave Oscillators              Square Wave Oscillators        
Triangle Wave Oscillators          Voltage Controlled Oscillators (VCO)   
 

• 40KHZ LED TEST SIGNAL GENERATOR
  This 40KHz crystal controlled oscillator circuit drives an infrared LED with powerful 40ma pulses.  The circuit can be used to test optical communications circuits, designed to receive 40KHz modulated light signals.

• Ultra Low Power 32KHz Crystal Oscillator
  I have used this circuit many times when I needed a low frequency reference, which did not draw much power.  With the components show, the current from a 3v battery is less than 1.2 microamps.

• VERY LOW POWER GATED CRYSTAL OSCILLATOR
  The circuit gates the output of a continuously operating 32KHz crystal oscillator to the input of a C-MOS buffer when clock pulses are needed. The technique gets around the problem of a slow starting crystal oscillator by keeping the oscillator going and switching on a transistor power stage only as needed. The method keeps the standby power consumption to a very low 1uA when used with a 3v supply.