Datasheet

R
S
A1
0.1 Fm
V+>3V
A2
R
L
Load
V
IN+
-16Vto+80V
Negative
and
Positive
Common-Mode
Voltage
V
IN+
V
IN-
V+
I
L
OUT
INA193-INA198
R
1
R
2
INA193, INA194
INA195, INA196
INA197, INA198
SBOS307F –MAY 2004–REVISED FEBRUARY 2010 www.ti.com
SHUTDOWN voltage loss in the measurement line. High values of
R
S
provide better accuracy at lower currents by
Because the INA193-INA198 consume a quiescent
minimizing the effects of offset, while low values of
current less than 1mA, they can be powered by either
R
S
minimize voltage loss in the supply line. For most
the output of logic gates or by transistor switches to
applications, best performance is attained with an R
S
supply power. Use a totem-pole output buffer or gate
value that provides a full-scale shunt voltage range of
that can provide sufficient drive along with 0.1mF
50mV to 100mV. Maximum input voltage for accurate
bypass capacitor, preferably ceramic with good
measurements is 500mV.
high-frequency characteristics. This gate should have
a supply voltage of 3V or greater because the
TRANSIENT PROTECTION
INA193-INA198 requires a minimum supply greater
than 2.7V. In addition to eliminating quiescent current,
The −16V to +80V common-mode range of the
this gate also turns off the 10mA bias current present
INA193-INA198 is ideal for withstanding automotive
at each of the inputs. An example shutdown circuit is
fault conditions ranging from 12V battery reversal up
shown in Figure 21.
to +80V transients, since no additional protective
components are needed up to those levels. In the
event that the INA193-INA198 is exposed to
transients on the inputs in excess of its ratings, then
external transient absorption with semiconductor
transient absorbers (zeners or Transzorbs) will be
necessary. Use of MOVs or VDRs is not
recommended except when they are used in addition
to a semiconductor transient absorber. Select the
transient absorber such that it will never allow the
INA193-INA198 to be exposed to transients greater
than +80V (that is, allow for transient absorber
tolerance, as well as additional voltage due to
transient absorber dynamic impedance). Despite the
use of internal zener-type ESD protection, the
INA193-INA198 does not lend itself to using external
resistors in series with the inputs because the internal
gain resistors can vary up to ±30%. (If gain accuracy
is not important, then resistors can be added in series
with the INA193-INA198 inputs with two equal
resistors on each input.)
OUTPUT VOLTAGE RANGE
The output of the INA193-INA198 is accurate within
the output voltage swing range set by the
Figure 21. INA193-INA198 Example Shutdown
power-supply pin, V+. This is best illustrated when
Circuit
using the INA195 or INA198 (which are both versions
using a gain of 100), where a 100mV full-scale input
from the shunt resistor requires an output voltage
SELECTING R
S
swing of +10V, and a power-supply voltage sufficient
to achieve +10V on the output.
The value chosen for the shunt resistor, R
S
, depends
on the application and is a compromise between
small-signal accuracy and maximum permissible
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