±20

±15

±10

±5

0

5

10

15

20

25

30

0

50

100

150

200

250

Differential Input Voltage (mV)

C027

IB+

IB-

Figure 7-10. 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 reaches the device is 9.8 mV. A measurement error of 2% is created as a

result of the external input filter resistors. Using 10-Ω input filter resistors instead of the 100-Ω resistors reduces

this added error from 2% to 0.2%.

7.4.4 Using the INA300 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 7-11, 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 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 SOT-523

or SOD-523 packages.

CBYPASS

0.1 µF

+2.7 V to 5.5 V

Power Supply

(0 V to 36 V)

Load

RLIMIT

RPull-up

10 k

VS

IN+

IN–

+

CMP

LIMIT

LATCH

DELAY

TI Device

GND

ENABLE

HYS

RPROTECT

≤100 Ω

–

ALERT

Figure 7-11. Transient Protection

www.ti.com

INA300

SBOS613C – FEBRUARY 2014 – REVISED JUNE 2021

Copyright © 2021 Texas Instruments Incorporated

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