INA200A BURR-BROWN [Burr-Brown Corporation], INA200A Datasheet - Page 11

• Manufacturer Part Number: INA200A
• Description: High-Side Measurement Current-Shunt Monitor with Comparator and Reference
• Manufacturer: BURR-BROWN [Burr-Brown Corporation]

In the Typical Characteristics, the Output Error vs
Common-Mode Voltage curve shows the highest
accuracy for the this region of operation. In this plot,
V
This case is also used to create the V
specifications in the Electrical Characteristics table.
Normal Case 2: V
This region of operation has slightly less accuracy than
Normal Case 1 as a result of the common-mode operating
area in which the part functions, as seen in the Output Error
vs Common-Mode Voltage curve. As noted, for this graph
V
becomes less than 12V, with a typical maximum error of
0.005% at the most negative V
Low V
V
Low V
V
Although the INA200 family of devices are not designed for
accurate operation in either of these regions, some
applications are exposed to these conditions. For
example, when monitoring power supplies that are
switched on and off while V
INA201, or INA202, it is important to know what the
behavior of the devices will be in these regions.
As V
device output accuracy degrades. A larger-than-normal
offset can appear at the current shunt monitor output with
a typical maximum value of V
V
returns to the expected output value with accuracy as
specified in the Electrical Characteristics. Figure 3
illustrates this effect using the INA202 (Gain = 100).
Low V
This region of operation is the least accurate for the
INA200 family. To achieve the wide input common-mode
voltage range, these devices use two op amp front ends in
Figure 3. Example for Low V
S
S
SENSE
SENSE
SENSE
= 12V; for V
= 12V; for V
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SENSE
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
SENSE
SENSE
0
SENSE
= 0mV. As V
< 20mV, −16V ≤ V
< 20mV, V
0
approaches 0mV, in these V
2
Case 1:
Case 3:
Case 2: V
CM
CM
(INA202, Gain = 100)
< 12V, the Output Error increases as V
4
≥ 12V, the output error is at its minimum.
SENSE
S
Actual
< V
6
SENSE
SENSE
CM
V
8
≥ 20mV, V
S
SENSE
CM
is still applied to the INA200,
≤ 80V
approaches 20mV, V
10
CM
< 0; and
< 20mV, 0V ≤ V
(mV)
Ideal
SENSE
= −16V.
12
SENSE
OUT
CM
14
Cases 1 and 3
CM
< V
= 300mV for
≥ 20mV output
16
regions, the
S
18
CM
≤ V
20
OUT
CM
S
parallel. One op amp front end operates in the positive
input common-mode voltage range, and the other in the
negative input region. For this case, neither of these two
internal amplifiers dominates and overall loop gain is very
low. Within this region, V
linear operation levels for Normal Case 2. This deviation
from linear operation becomes greatest the closer V
approaches 0V. Within this region, as V
20mV, device operation is closer to that described by
Normal Case 2. Figure 4 illustrates this behavior for the
INA202. The V
by maintaining a constant V
sweeping V
peaks during this test varies from part to part, but the V
maximum peak is tested to be less than the specified V
tested limit.
SELECTING R
The value chosen for the shunt resistor, R
the application and is a compromise between small-signal
accuracy and maximum permissible voltage loss in the
measurement line. High values of R
accuracy at lower currents by minimizing the effects of
offset, while low values of R
supply line. For most applications, best performance is
attained with an R
voltage range of 50mV to 100mV. Maximum input voltage
for accurate measurements is 500mV.
TRANSIENT PROTECTION
The −16V to +80V common-mode range of the INA200,
INA201, and INA202 is ideal for withstanding automotive
fault conditions ranging from 12V battery reversal up to
+80V
components are needed up to those levels. In the event
that the INA200, INA201, and INA202 are exposed to
transients on the inputs in excess of their ratings, then
external transient absorption with semiconductor transient
absorbers (such as zeners) will be necessary. Use of
NOTE: (1) INA200 V
2.4
2.2
2.0
1.8
1.6
1.4
1.2
1.0
0.8
0.6
0.4
0.2
Figure 4. Example for Low V
0
0
INA202 V
transients,
V
CM4
2
CM
4
from 0V to V
OUT
OUT
OUT
V
(INA202, Gain = 100)
Tested Limit
CM3
6
S
S
V
from part to part of the V
maximum V
Tested Limit = 0.4V. INA201 V
maximum peak for this case is tested
V
CM2
value that provides a full-scale shunt
CM2
8
since
, V
V
OUT
CM3
10
SENSE
V
V
(1)
S
, and V
OUT
SENSE
OUT
. The exact V
S
12 14 16 18 20 22
approaches voltages close to
S
, setting V
(mV)
minimize voltage loss in the
no
V
with V
tested limit at
CM1
= 0mV, 0 ≤ V
CM4
SBOS374 − NOVEMBER 2006
illustrate the variance
SENSE
additional
CM
SENSE
that can cause
< 20mV.
SENSE
SENSE
S
OUT
CM
CM1
provide better
S
Tested Limit = 1V.
at which V
≤ V
, depends on
Case 2
Ideal
approaches
= 0mV and
S.
protective
INA200
INA201
INA202
24
SENSE
OUT
OUT
OUT
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