HA17901 查看數據表（PDF） - Hitachi -> Renesas Electronics

零件编号

产品描述 (功能)

生产厂家

HA17901

Quadruple Comparators

Hitachi -> Renesas Electronics 

HA17901, HA17339 Series

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.

VCC

R1 1M D1 IS2076

R2 100k D2 IS2076

C

80pF

VCC

–

HA17901

VCC

+

1M

1M 1M

Vout

Figure 3 Pulse Generator

Horizontal: 2 V/div, Vertical: 20 µs/div, VCC = 5 V Horizontal: 5 V/div, Vertical: 20 µs/div, VCC = 15 V

Figure 4 Operating Waveforms

3. Voltage Controlled Oscillator

In the circuit in figure 5, comparator A1 operates as an integrator, A2 operates as a comparator with

hysteresis, and A3 operates as the switch that controls the oscillator frequency. If the output Vout1 is at

the low level, the A3 output will go to the low level and the A1 inverting input will become a lower

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 A1 exceeds the level on the comparator A2

inverting input, A2 inverts to the high level and both the output Vout1 and the A3 output go to the high

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

the low level. Then, when the A1 output level becomes lower than the level on the A2 noninverting

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.

11

Share Link: