INA193,INA194

INA195,INA196

INA197,INA198

SBOS307B − MAY 2004 − REVISED JUNE 2004

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7

APPLICATIONS INFORMATION

BASIC CONNECTION

Figure 1 shows the basic connection of the INA19x. The

as possible to the shunt resistor to minimize any resistance

in series with the shunt resistance.

Power-supply bypass capacitors are required for stability.

Applications with noisy or high impedance power supplies

may require additional decoupling capacitors to reject

power-supply noise. Connect bypass capacitors close to

the device pins.

Load

−16Vto+36V

V

IN

−

+2.7V to +13.5V

V+

OUT

INA193 −INA198

5k

Ω

5k

Ω

Figure 1. INA19x Basic Connection

POWER SUPPLY

The input circuitry of the INA19x can accurately measure

beyond its power-supply voltage, V+. For example, the V+

power supply can be 5V, whereas the load power-supply

voltage is up to +36V. The output voltage range of the OUT

terminal, however, is limited by the voltages on the

power-supply pin.

the application and is a compromise between small-signal

accuracy and maximum permissible voltage loss in the

accuracy at lower currents by minimizing the effects of

supply line. For most applications, best performance is

voltage range of 50mV to 100mV. Maximum input voltage

for accurate measurements is 500mV.

TRANSIENT PROTECTION

The −16V to +36V common-mode range of the INA19x is

ideal for withstanding automotive fault conditions ranging

from 12V battery reversal up to +36V transients, since no

additional protective components are needed up to those

levels. In the event that the INA19x 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 INA19x to be exposed to transients greater than +36V

(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 INA19x does not lend itself to using external

resistors in series with the inputs since the internal gain

resistors can vary up to

±30%. (If gain accuracy is not

important, then resistors can be added in series with the

INA19x inputs with two equal resistors on each input.)

OUTPUT VOLTAGE RANGE

The output of the INA19x is accurate within the output

voltage swing range set by the power supply pin, V+. This

is best illustrated when 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 swing of +10V, and a power-supply voltage

sufficient to achieve +10V on the output.