Time (1

s/div)

-20

0.25

-10

0.5

0

0.75

10

1

20

1.25

30

1.5

40

1.75

50

2

60

2.25

70

2.5

80

2.75

90

3

100

3.25

Common-mode Voltage

Output Voltage

Figure 8-1. Enhanced PWM Rejection Performance

Figure 8-1 shows the INA241x PWM enhancement performance. When INA241x senses the large common-

mode ΔV/Δt transients, it holds the output for 1 μs, thereby preventing the common-mode disturbance from

propagating to the output. If another common-mode transient occurs during the following 3 μs, INA241x relies

on high BW and AC CMMR to attenuate the effect of common-mode transient. The enhanced PWM rejection

is achieved up to a PWM frequency of 125 kHz or if common-mode transient edges are separated by a 3 μs

interval or more.

8.3.1.2 Input-Signal Bandwidth

The INA241x is available with several gain options including 10 V/V, 20 V/V, 50 V/V, 100 V/V, and 200 V/V.

The unique multistage design enables the amplifier to achieve high bandwidth of 1.1 MHz at all gains. This high

bandwidth provides the throughput and fast response that is required for the rapid detection and processing of

over-current events.

8.3.1.3 Low Input Bias Current

The INA241x inputs draw 35 µA (typical) bias current per input pin at common-mode voltages as high as 110 V,

which enables precision current sensing on applications that require lower current leakage. Unlike many high

voltage current sense amplifiers whose input bias currents are proportional to the common-mode voltage, the

input bias current of the INA241x remains constant over the entire common-mode voltage range.

8.3.1.4 Low VSENSE Operation

The INA241x features high performance operation across the entire valid VSENSE range. The zero-drift input

architecture of the INA241x provides the low offset voltage and low offset drift needed to measure low

VSENSE levels accurately across the wide operating temperature of –40°C to +125°C. Low VSENSE operation

is particularly beneficial when using low ohmic shunts for low current measurements, as power losses across the

shunt are significantly reduced.

8.3.1.5 Wide Fixed Gain Output

The INA241x maximum gain error is ±0.01% at room temperature, with a maximum drift of ±1 ppm/°C over the

full temperature range of –40°C to +125°C. The INA241x is available in multiple gain options of 10 V/V, 20 V/V,

50 V/V, 100 V/V, and 200 V/V, which the system designer should select based on their desired signal-to-noise

ratio and other system requirements, such as the dynamic current range and full-scale output voltage target.

8.3.1.6 Wide Supply Range

The INA241x operates with a wide supply range from 2.7 V to 20 V. While the input common-mode voltage

range of the INA241x is independent of the supply voltage, the output voltage is bound by the supply voltage

INA241A, INA241B

SBOSA30A – MARCH 2022 – REVISED AUGUST 2022

www.ti.com

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