HA17339A Datasheet, PDF (11/15 Pages) Renesas Technology Corp – Quadruple Comparators

HA17339A Series
4. Basic Comparator
The circuit shown in figure 6 is a basic comparator. When the input voltage V_IN exceeds the reference voltage V_REF,
the output goes to the high level.
V_CC
Vin
V_REF
+
HA17339A
−
3kΩ
Figure 6 Basic Comparator
5. Noninverting Comparator (with Hysteresis)
Assuming +V_IN is 0V, when V_REF is applied to the inverting input, the output will go to the low level (approximately
0V). If the voltage applied to +V_IN is gradually increased, the output will go high when the value of the noninverting
input, +V_IN × R₂/(R₁ + R₂), exceeds +V_REF. Next, if +V_IN is gradually lowered, Vout will be inverted to the low
level once again when the value of the noninverting input, (Vout – V_IN) × R₁/(R₁ + R₂), becomes lower than V_REF.
With the circuit constants shown in figure 7, assuming V_CC = 15V and +V_REF = 6V, the following formula can be
derived, i.e. +V_IN × 10M/(5.1M + 10M) > 6V, and Vout will invert from low to high when +V_IN is > 9.06V.
(Vout
−
V_IN)
×
R₁
R₁ + R₂
+
V_IN
<
6V
(Assuming Vout = 15V)
When +V_IN is lowered, the output will invert from high to low when +V_IN < 1.41V. Therefore this circuit has a
hysteresis of 7.65V. Figure 8 shows the input characteristics.
+V_REF
+Vin
R₁
5.1M
V_CC
−
HA17339A
+
10M
R₂
V_CC
3k
Vout
Figure 7 Noninverting Comparator
20
V_CC = 15 V, +V_REF = 6 V
+Vin = 0 to 10 V
16
12
8
4
0
0
5
10
15
Input Voltage V_IN (V)
Figure 8 Noninverting Comparator I/O Transfer Characteristics
Rev.3.00 Mar 10, 2006 page 11 of 14