LM339
Typical Applications Circuit
+ V
CC
R3
10k
V
in
+ VCC
Rref
±
+
R2
1.0M
VCCR1
Vref
≈
Rref+ R1
R1
Vin
R2
10k
R3
1.0M
Vref =
VCCR1
Rref+ R1
+V
CC
10 k
VO
Rref
Vref
±
+
10k
VO
Vref
10k R1
≈
R1/ / Rref/ / R2
R1/ / Rref
R1// Rref+ R2
Rref/ / /R1
[V
O(max) -V
O(min)]
VH =
R2
≈
R1/ / Rref
Amount of Hysteresis VH
R2
VH =
[(V
V
]
R2+ R3 O(max) - O(min)
Figure
1
1. Inverting Comparator
with Hystersis
Figure
2
. Noninverting Comparator
with Hysteresis
VCC
VCC
.
4.0V
100k
+
C
VCC
R2
330k
R4
RL
k
Ω
100
10
330k
R1
±
+
R3
330k
VO
VCC
T1
10k
V
in
V ref
RS
+
±
RL
R1
RS = Source Resistance
R1
≈
RS
Logic
CMOS
TTL
Device
1/4 MC14001
1/4 MC7400
VCC
(V)
+15
+5.0
T2
T1 = T2= 0.69RC
7.2
f
=
C( F)
µ
R2= R3= R4
R2// R3// R4
Figure
3.
Driving Logic
Figure
4
. Squarewave Oscillator
BEIJING ESTEK ELECTRONICS CO.,LTD
5
ESTEK [ Estek Electronics Co. Ltd ]
