HA17901, HA17339 Series

11

2. Pulse Generator

The charge and discharge circuits in the circuit from figure 1 are separated by diodes in this circuit. (See

figure 3.) This allows the pulse width and the duty cycle to be set independently. Figure 4 shows the

waveforms generated by this circuit.

–

+

HA17901

Vout

1M

1M

1M

C

80pF

Figure 3 Pulse Generator

Horizontal: 5 V/div, Vertical: 20

µs/div, V

Horizontal: 2 V/div, Vertical: 20

µs/div, V

Figure 4 Operating Waveforms

3. Voltage Controlled Oscillator

In the circuit in figure 5, comparator A

hysteresis, and A

the low level, the A

level than the A1 noninverting input. The A1 output will integrate this state and its output will increase

towards the high level. When the output of the integrator A

inverting input, A

level. This causes the integrator to integrate a negative state, resulting in its output decreasing towards

the low level. Then, when the A

input, the output Vout1 is once again inverted to the low level. This operation generates a square wave

on Vout1 and a triangular wave on Vout2.