ha17901at Renesas Electronics Corporation., ha17901at Datasheet - Page 11

• Manufacturer Part Number: ha17901at
• Description: Quadruple Comparators
• Manufacturer: Renesas Electronics Corporation.

HA17901A Series
3. Voltage Controlled Oscillator
4. Basic Comparator
Rev.1.00 Mar 10, 2006 page 11 of 15
In the circuit in figure 5, comparator A
A
will go to the low level and the A1 inverting input will become a lower level than the A1 noninverting input. The
A
integrator A
Vout1 and the A
output decreasing towards the low level. Then, when the A
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.
The circuit shown in figure 6 is a basic comparator. When the input voltage V
the output goes to the high level.
+V
Frequency
control
voltage
input
V
+250 mV
700 Hz
CC
3
1
C
operates as the switch that controls the oscillator frequency. If the output Vout1 is at the low level, the A
output will integrate this state and its output will increase towards the high level. When the output of the
= 30 V
/
100 k
+V
1
100 kHz
exceeds the level on the comparator A
C
3
output go to the high level. This causes the integrator to integrate a negative state, resulting in its
+50 V
50 k
20 k
0.1
10
20 k
Figure 5 Voltage Controlled Oscillator
V
+
HA17901A
1
Figure 6 Basic Comparator
REF
Vin
HA17901A
operates as an integrator, A
V
A
CC
3
V
A
CC
500 p
1
+
+
HA17901A
2
inverting input, A
0.01
V
3 k
CC
V
/2
1
CC
output level becomes lower than the level on the A
V
5.1 k
V
CC
CC
2
3 k
/2
operates as a comparator with hysteresis, and
2
inverts to the high level and both the output
IN
+
HA17901A
exceeds the reference voltage V
V
100 k
CC
A
2
3 k
V
CC
Output 1
Output 2
3
output
REF
2
,