Sawtooth generator circuit II
Posted on Dec 11, 2010 6948
- Oscillator Circuits
Crossing various sawtooth voltage generator, the common denominator is the use of a capacitor charge. Discharge effect to generate a sawtooth voltage of the forward and inverse
process. Simple sawtooth voltage generator circuit is simple, but the output voltage linear sawtooth poor voltage amplitude changes exponentially with time, departing from the linear serious, and power efficiency is not high. To get a good linear sawtooth core voltage crossing, the key is to try to make the scan of the capacitor to maintain constant current charging within, which is the basic point of departure for a constant current source sawtooth voltage generator. Constant is the use of flooded common base connected transistor law in emission current J. Linden Certainly, the collector current is essentially unchanged, maintaining the capacitor charging characteristics to achieve this constant stream of linear scan. But when the constant current circuit with a transistor change after the scan voltage amplitude and is saturated, the scanning voltage will not change, the output voltage waveform appears flattened, therefore, in this circuit, the output amplitude of certain restrictions the most significant v, rhn, only mound -Ut. To make the scanning wave does not appear flattened and distorted, the best period of the scan (ie, the maximum scan cycle) 1, Li; they should charge the capacitor to the output of the transistor VT1 maximum time required for the amplitude of a million, such as circuit FIG. He was excited by the scanning of a sawtooth generator (Tp), quiescent (z,) and period (n), depending on the telogen, pulse width and period of the input signal, only generator retrace period by the circuit itself parameters decision.