Datasheet

WINDOW COMPARATOR
V =
H
R
2
R + R
1 2
´ V
S
(5)
V =
L
R
4
R + R
3 4
´ V
S
(6)
V
S
A1
A2
D1
(2)
D2
(2)
R
5
10kW
R
6
5.1kW
R
7
5.1kW
R
IN
2kW
(1)
V
S
V
S
Q1
(3)
R
1
V
H
V
L
R
2
1/2
OPA2369
1/2
OPA2369
V
S
V
OUT
V
IN
V
S
R
3
R
4
NOTES: (1)R protectsA1andA2frompossibleexcesscurrentflow.
IN
(2)IN4446orequivalentdiodes.
(3)2N2222orequivalentNPNtransistor.
OPA369
OPA2369
www.ti.com ............................................................................................................................................ SBOS414B – AUGUST 2007 – REVISED DECEMBER 2008
If V
IN
falls below V
L
, the output of A2 is high, current
flows through D2, and V
OUT
is low. Likewise, if V
IN
Figure 26 shows the OPA2369 used as a window
rises above V
H
, the output of A1 is high, current flows
comparator. The threshold limits are set by V
H
and
through D1, and V
OUT
is low. The window comparator
V
L
, with V
H
> V
L
. When V
IN
< V
H
, the output of A1 is
threshold voltages are set as follows:
low. When V
IN
> V
L
, the output of A2 is low.
Therefore, both op amp outputs are at 0V as long as
V
IN
is between V
H
and V
L
. This architecture results in
no current flowing through either diode, Q1 in cutoff,
with the base voltage at 0V, and V
OUT
forced high.
Figure 26. OPA2369 as a Window Comparator
Copyright © 2007 – 2008, Texas Instruments Incorporated Submit Documentation Feedback 11
Product Folder Link(s): OPA369 OPA2369