astable_circuits

MICROPOWER C-MOS OSCILLATOR, DRAWS ONLY 0.5uA (6) (500na0) If truly low power oscillators interest you, this circuit draws a mere 2 watts (500nA) from a 6v battery. It uses a very inexpensive C-MOS IC to produce a frequency of 2Hz. However, by changing the component values you can push it to 300Hz. The circuit draws much less current than traditional C-MOS oscillators using a Schmitt trigger inverter. It also produces fast leading edges. However, if you need more drive current, a C-MOS buffer should be included. Published in EDN, September 2, 1993.

PRECISION ULTRA LOWER POWER OSCILLATOR (49) (10secosc) This circuit works much like the classic 555 timer, but draws only about 1.5 microamps from a 3 volt battery. It is highly stable under varying temperature and supply voltages.

VERY LOW POWER ASTABLE MULTIVIBRATOR (53) (astable) This classic circuit draws only 200 nanoamps from a 1.5v supply.

CHEAP LOW POWER 3V 2Hz OSCILLATOR (62) (2hzosc) This is yet another method to generate low frequency output pulses. The circuit uses an inexpensive under-voltage monitor IC and a couple of cheap MOSFETs. It could easily be modified to produce pulse frequencies from about one cycle per minute to a maximum of about 10KHz. It draws only about 1uA from a 3v battery. This circuit should not be used if frequency stability is important, since it will change as a function of supply voltage.

CMOS SCHMITT TRIGGER IC MAKES VCO (124) (4584vco) By changing the supply voltage fed to a classic 4584 Schmitt trigger type oscillator, the oscillator frequency can be changed over a range of 50:1. A 74HCU04 inverter is used at the output of the 4584 to maintain a constant TTL logic level signal.

Astable Multivibrator 1:

Astable Multivibrator 2:

Flip-Flop Flashers, Buzzers, Etc.: