8 Detailed Description

8.1 Overview

The INA296x-Q1 is a high-side, inline, or low-side bidirectional, high-speed current-sense amplifier that offers

a wide common-mode range, precision zero-drift topology, excellent common-mode rejection ratio (CMRR)

and fast slew rate. Different gain versions are available to optimize the output dynamic range based on the

application. The INA296x-Q1 is designed using an architecture that enables low bias currents of 35 µA with a

specified common-mode voltage range from –5 V to 110 V with signal bandwidths up to 1.1 MHz.

8.2 Functional Block Diagram

+

±

+

±

IN+

IN-

GND

V

S

REF1

REF2

OUT

8.3 Feature Description

8.3.1 Amplifier Input Common-Mode Signal

The INA296x-Q1 supports large input common-mode voltages from –5 V to +110 V. The internal topology of

the INA296x-Q1 allows the common-mode range to exceed the power-supply voltage (VS). This allows for the

INA296x-Q1 to be used for low-side, inline, and high-side current-sensing applications that extend beyond the

supply range of 2.7 V to 20 V.

8.3.1.1 Input-Signal Bandwidth

The INA296x-Q1 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.

8.3.1.2 Low Input Bias Current

The INA296x-Q1 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 INA296x-Q1 remains constant over the entire common-mode voltage range.

8.3.1.3 Low VSENSE Operation

The INA296x-Q1 features high performance operation across the entire valid VSENSE range. The zero-drift input

architecture of the INA296x-Q1 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.

8.3.1.4 Wide Fixed Gain Output

The INA296x-Q1 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 INA296x-Q1 is available in multiple gain options of 10

INA296A-Q1, INA296B-Q1

SBOSA32A – FEBRUARY 2023 – REVISED AUGUST 2023

www.ti.com

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