7 Detailed Description

7.1 Overview

The INA293 is a high- or low-side current-sense amplifier that offers a wide common-mode range, precision

zero-drift topology, excellent common-mode rejection ratio (CMRR), high bandwidth and fast slew rate. Different

gain versions are available to optimize the output dynamic range based on the application. The INA293 is

designed using a transconductance architecture with a current-feedback amplifier that enables low bias currents

of 20 μA with a common-mode voltage of 110 V.

7.2 Functional Block Diagram

IN+

IN±

OUT

-

+

Buffer

Current

Feedback

VS

GND

RL

R1

R1

Bias

Load

RSENSE

ISENSE

Load

Supply

7.3 Feature Description

7.3.1 Amplifier Input Common-Mode Signal

The INA293 supports large input common-mode voltages from –4 V to +110 V. Because of the internal topology,

the common-mode range is not restricted by the power-supply voltage (VS). This allows for the INA293 to be

used for both low and high side current-sensing applications.

7.3.1.1 Input-Signal Bandwidth

The INA293 –3-dB bandwidth is gain dependent, with several gain options of 20 V/V, 50 V/V, 100 V/V, 200 V/V,

and 500 V/V. The unique multistage design enables the amplifier to achieve high bandwidth at all gains. This

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

of overcurrent events.

The bandwidth of the device also depends on the applied VSENSE voltage. Figure 7-1 shows the bandwidth

performance profile of the device over frequency as output voltage increases for each gain variation. As shown

in Figure 7-1, the device exhibits the highest bandwidth with higher VSENSE voltages, and the bandwidth is

higher with lower device gain options. Individual requirements determine the acceptable limits of error for high

frequency current-sensing applications. Testing and evaluation in the end application or circuit is required to

determine the acceptance criteria, and to validate that the performance levels meet the system specifications.

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INA293

SBOS470B – DECEMBER 2019 – REVISED AUGUST 2022

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