Non-saturated multivibrator using a Schmitt trigger with a current mirror

The circuit of a bipolar multivibrator which does not include saturated switches is proposed. The circuit is a modification of the multivibrator with a simple (three transistor) Schmitt trigger. An additional current mirror is directly connected to the collector circuit of the Schmitt trigger differential pair. The circuit operation is described and the operation frequency ƒ0 is calculated. The power supply voltage sensitivity and temperature coefficient of ƒ0 are derived. An example of circuit design using integrated transistor arrays is given and the design limitations are introduced. The design was verified experimentally. The clear triangular and rectangular wave shapes are preserved for frequencies up to 300 kHz and the circuit is able to oscillate at frequencies above 2 MHz.