MAX9015AEKA+T Maxim Integrated Products, MAX9015AEKA+T Datasheet - Page 13

• Manufacturer Part Number: MAX9015AEKA+T
• Description: IC COMPARATOR SNGL SOT23-8
• Manufacturer: Maxim Integrated Products
• Series: Beyond-the-Rails™r
• Type: with Voltage Referencer

Specifications of MAX9015AEKA+T

• Number Of Elements: 1
• Output Type: CMOS, Push-Pull, Rail-to-Rail
• Voltage - Supply: 1.8 V ~ 5.5 V
• Mounting Type: Surface Mount
• Package / Case: SOT-23-8
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: MAX9015AEKA+T; MAX9015AEKA+TTR

6) Verify the trip voltages and hysteresis as follows:
The MAX9016/MAX9018/MAX9020 feature a built-in 4mV
hysteresis band. These devices have open-drain outputs
and require an external pullup resistor (Figure 3).
Additional hysteresis can be generated using positive
feedback, but the formulas differ slightly from those of
the MAX9015/MAX9017/MAX9019. Use the following
procedure to calculate resistor values:
1) Select R3. Input bias current at IN_+ is less than
2) Choose the hysteresis band required (V
3) Calculate R1 according to the following equation.
V
times R1 divided by the parallel combination of R1,
R2:
and R3.
V
Hysteresis = V
2nA, so the current through R3 should be at least
0.2µA to minimize errors caused by input bias cur-
rent. The current through R3 at the trip point is
(V
put states in solving for R3 yields two formulas: R3
= V
smaller of the two resulting resistor values. For
example, when using the MAX9018 (V
and V
R4 = 1MΩ, then the two resistor values are 6.2MΩ
and 18MΩ. Choose a 6.2MΩ standard value for R3.
For this example, insert the values:
IN
IN
REF
V
REF
falling: = 2.942V:
rising: = 2.992V, which is equivalent to REF
THR
R
CC
- V
1
/I
V
R3
=
=
OUT
THF
= 5V, and if we choose I
R
V
( .
or R3 = [(V
1
6 2
(MAX9016/MAX9018/MAX9020)
REF
SOT23, Dual, Precision, 1.8V, Nanopower
)/R3. Considering the two possible out-
=
=
THR
M
______________________________________________________________________________________
(
V
R
x R
Ω +
THR
3
- V
1
+
−
⎡
⎢
⎣
1
THF
R
Comparators With/Without Reference
⎛
⎜
⎝
M
CC
4
R
⎛
⎜
⎝
1
Additional Hysteresis
Ω
)
1
R x V
(Open-Drain Outputs)
1
⎞
⎟ +
⎠
= 50mV.
⎛
⎜
⎝
)
- V
V
V
R
⎛
⎜
⎝
HB
CC
50
3
REF
⎛
⎜
⎝
5
CC
R
mV
⎞
⎟
⎠
V
1
2
)/I
⎞
⎟
⎠
⎞
⎟ +
⎠
⎞
⎟ =
⎠
R3
R3
] - R4. Use the
⎛
⎜
⎝
= 0.2µA, and
REF
72
R
HB
1
3
k
⎞
⎟
⎠
).
Ω
= 1.24V)
⎤
⎥
⎦
4) Choose the trip point for V
5) Calculate R2 as follows:
6) Verify the trip voltages and hysteresis as follows:
Figure 3. MAX9016/MAX9018/MAX9020 Additional Hysteresis
R
2
V
V
(V
threshold voltage at which the comparator switches
its output from low to high as V
trip point. For this example, choose 3V:
For this example, choose a 49.9kΩ standard value.
Hysteresis = V
IN
=
IN
V
THR
IN
ri
falling V
⎡
⎢
⎢
⎣
⎛
⎜
⎝
sin :
R
1 24
.
2
is the trip point for V
g V
R1
:
=
V x
3 0
.
THR
V
THF
⎡
⎢
⎢
⎣
THR
V
⎛
⎜
⎝
72
THR
V
REF
k
=
=
=
R2
−
Ω
V
>
V
V
3 043
V
THR
⎞
⎟ −
⎠
REF
R
- V
.
V
REF
REF
3
x R
REF
THF
R
1
+
⎛
⎜
⎝
1
R3
V
x R
x R
72
1
R
⎞
⎟ −
⎠
⎛
⎜
⎝
4
1
= 50mV.
IN
k
1
1
1
V
Ω
V
V
1
EE
CC
+
CC
x V
⎛
⎜
⎝
⎛
⎜
⎝
rising (V
⎞
⎟ −
⎠
⎛
⎜
⎝
⎛
⎜
⎝
IN
⎛
⎜
⎝
MAX9016
MAX9018
MAX9020
V
V
R
R
R
1
1
CC
HB
1
1
CC
1
1
⎛
⎜
⎝
rising). This is the
⎞
⎟ +
⎠
⎞
⎟ +
⎠
IN
⎞
⎟ −
⎠
6 2
OUT
.
⎞
⎟
⎠
=
rises above the
1
M
THR
⎛
⎜
⎝
2 993
⎛
⎜
⎝
⎛
⎜
⎝
Ω
R
.
R
R
1
1
2
2
1
⎞
⎟
⎠
3
) such that:
⎤
⎥
⎥
⎦
⎞
⎟ +
⎠
⎞
⎟ +
⎠
⎞
⎟
⎠
V
=
R4
⎤
⎥
⎥
⎦
51 1
⎛
⎜
⎝
⎛
⎜
⎝
R
R
1
1
.
3
3
k
⎞
⎟
⎠
⎞
⎟
⎠
13
Ω
⎞
⎟
⎠
⎞
⎟
⎠