AD8564AR Analog Devices Inc, AD8564AR Datasheet - Page 10
![IC COMPARATOR QUAD 7NS 16-SOIC](/photos/6/56/65617/505-16-soic_n__sml.jpg)
AD8564AR
Manufacturer Part Number
AD8564AR
Description
IC COMPARATOR QUAD 7NS 16-SOIC
Manufacturer
Analog Devices Inc
Type
General Purposer
Datasheet
1.AD8564ARUZ-REEL.pdf
(12 pages)
Specifications of AD8564AR
Mounting Type
Surface Mount
Output Type
CMOS, TTL
Rohs Status
RoHS non-compliant
Number Of Elements
4
Package / Case
16-SOIC (0.154", 3.90mm Width)
Comparator Type
General Purpose
No. Of Comparators
4
Amplifier Case Style
NSOIC
No. Of Pins
16
Peak Reflow Compatible (260 C)
No
No. Of Circuits
4
Leaded Process Compatible
No
Rohs Compliant
No
Lead Free Status / RoHS Status
Contains lead / RoHS non-compliant
Available stocks
Company
Part Number
Manufacturer
Quantity
Price
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AD8564AR
Manufacturer:
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Quantity:
20 000
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Part Number:
AD8564ARUZ
Manufacturer:
ADI/亚德诺
Quantity:
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Part Number:
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ADI
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Part Number:
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AD8564
USING HYSTERESIS
Hysteresis can easily be added to a comparator through the
addition of positive feedback. Adding hysteresis to a comparator
offers an advantage in noisy environments where it is not desirable
for the output to toggle between states when the input signal is
near the switching threshold. Figure 17 shows a method for
configuring the AD8564 with hysteresis.
The input signal is connected directly to the inverting input of
the comparator. The output is fed back to the noninverting
input through R2 and R1. The ratio of R1 to R1 + R2 and the
output swing establishes the width of the hysteresis window,
with V
switching voltage. The output switches high when the input
REF
setting the center of the window or the average
Figure 17. Configuring the AD8564 with Hysteresis
V
REF
SIGNAL
R1
COMPARATOR
R2
C
F
Rev. B | Page 10 of 12
voltage is greater than V
the input voltage is less than V
where V
The C
the feedback network. This has the effect of increasing the
amount of hysteresis at high frequencies. This can be useful
when comparing a relatively slow signal in a high frequency
noise environment.
At frequencies greater than
window approaches V
At frequencies less than f
in Equation 1.
V
V
F
HI
LO
capacitor may also be added to introduce a pole into
+
=
=
is the positive supply voltage.
(
V
V
REF
+
−
⎛
⎜
⎜
⎝
1
1
−
−
V
R1
REF
HI
R1
HI
= V
+
P
)
, the threshold voltages remain as it is
R1
and does not switch low again until
R2
+
f
R1
P
+
– 1 V and V
⎞
⎟
⎟
⎠
LO
=
R2
, as given in Equation 2.
2
V
π
C
REF
1
F
R2
LO
, the hysteresis
= 0 V.
(1)
(2)