0.1 µF

+2.7 V to 5.5 V

Power Supply

(0 V to 36 V)

Load

10 k

IN+

IN

+

-

CMP

LIMIT

LATCH

DELAY

ALERT

INA300

GND

ENABLE

HYS

”100

±20

±15

±10

±5

0

5

10

15

20

25

30

0

50

100

150

200

250

Differential Input Voltage (mV)

C027

IB+

IB-

21

INA300

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SBOS613B – FEBRUARY 2014 – REVISED APRIL 2016

Product Folder Links: INA300

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Copyright © 2014–2016, Texas Instruments Incorporated

Figure 31. Input Bias Current vs Differential Input Voltage

For example, with a differential voltage of 10 mV developed across a current-sensing resistor and using 100-

Ω

resistors, the differential signal that actually reaches the device is 9.8 mV. A measurement error of 2% is created

as a result of these external input filter resistors. Using 10-

Ω input filter resistors instead of the 100-Ω resistors

reduces this added error from 2% down to 0.2%.

7.4.4 Using the INA300 With Common-Mode Transients Above 36 V

With a small amount of additional circuitry, the device can be used in circuits subject to transients higher than

36 V. Use only zener diodes or zener-type transient absorbers (sometimes referred to as Transzorbs). Any other

type of transient absorber has an unacceptable time delay. Start by adding a pair of resistors, as shown in

Figure 32, as a working impedance for the zener diode. Keeping these resistors as small as possible is best,

preferably 100

Ω or less. Larger values can be used with an additional error induced resulting from a reduced

signal that actually reaches the device input terminals. Because this circuit limits only short-term transients, many

applications are satisfied with a 100-

Ω resistor along with conventional zener diodes of the lowest power rating

available. This combination uses the least amount of board space. These diodes can be found in packages as

small as SOT-523 or SOD-523.

Figure 32. Transient Protection