Texas Instruments INA168NA/250

Overview

INA168NA/250 from Texas Instruments is a unipolar high-side current shunt monitor IC designed for precision measurement of load current via a sense resistor in systems with up to 60 V common-mode voltage. It features 200 µA/V transconductance, ±1 mV max offset voltage at +25°C, 25 µA typical quiescent current, and operates from –40°C to +125°C in a 5-pin SOT-23 package. It is used in battery chargers and power management circuits where accurate high-side sensing is required without ground-referenced shunt placement.

For engineers reviewing the INA168NA/250 datasheet, INA168NA/250 pinout, INA168NA/250 application, or INA168NA/250 equivalent, key selection considerations include its 2.7 V to 60 V supply range, independent input common-mode voltage capability up to 60 V, single-resistor gain configuration, low quiescent current for battery-sensitive designs, and compatibility with ADC buffering architectures.

Technical Context

The INA168NA/250 implements a high-voltage precision op amp with trimmed thin-film resistors and a low-noise output transistor to convert differential shunt voltage into a proportional output current. Its input stage operates independently of V+ supply, enabling true high-side sensing where VIN+ can exceed V+ by up to 57.3 V (e.g., VIN+ = 60 V, V+ = 2.7 V).

It delivers 200 µA/V transconductance with ±0.1% nonlinearity over 10–150 mV input range, bandwidth of 32 kHz with 125 kΩ load, and maintains <±2.5% total output error across –40°C to +125°C. Output compliance is governed by VOUT ≤ (V+) – 0.7 V – VSENSE and VOUT ≤ VIN– – 0.5 V.

Key Specifications

Pinout & Package

INA168NA/250 is housed in a 5-pin SOT-23 package (DBV), with exposed pad not electrically connected. The package measures 2.90 mm × 1.60 mm × 1.45 mm and is RoHS-compliant.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar high-side current sensing applications.

Compared with INA168NA/250, INA240A1IDR trades 72× higher quiescent current for 12.5× bandwidth and near-zero drift, while MAX4080TASA+ sacrifices gain configurability and package size for reduced design complexity and marginally higher voltage rating.

Availability

INA168NA/250 is available at Aetrix Electronics and suitable for battery chargers, industrial power supplies, and telecom rectifiers requiring stable component supply, long-lifecycle support, and guaranteed traceable sourcing.

Supply support for INA168NA/250 includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets since 1930.

The INA168NA/250 belongs to TI's precision current-sense amplifier product line, engineered specifically for high-accuracy, high-common-mode, unipolar current measurement in space-constrained and thermally demanding environments.

FAQ

What is the maximum common-mode voltage supported by the INA168NA/250?

The INA168NA/250 supports an input common-mode voltage range of 2.7 V to 60 V. This means VIN+ and VIN– can each sit at up to 60 V relative to ground, enabling direct sensing on high-voltage rails such as 48 V battery systems or industrial DC buses. Absolute maximum rating extends to 75 V, but operation beyond 60 V is outside specified performance limits.

Can the INA168NA/250 measure bidirectional current?

No, the INA168NA/250 is a unipolar high-side current shunt monitor and only supports measurement of current flowing in one direction-from VIN+ to VIN–. For bidirectional sensing, two INA168NA/250 devices must be used in opposing configurations with external logic (e.g., comparators or multiplexers), as documented in TI's SBOS122E datasheet Figure 15.

How is gain set on the INA168NA/250?

Gain is set exclusively by the external load resistor R_L connected between the OUT pin and ground. The transfer function is V_OUT = I_OUT × R_L, where I_OUT = 200 µA/V × V_SENSE. For example, a 10 kΩ R_L yields a system gain of 2 V/V; a 50 kΩ R_L yields 10 V/V. No internal resistors or pins configure gain.

Does the INA168NA/250 require a minimum load on its output?

No, the INA168NA/250 does not require a minimum load. Its output is a current source with very high output impedance (>1 GΩ), so it functions correctly with R_L values from 5 kΩ to 500 kΩ. However, using R_L < 5 kΩ reduces bandwidth and increases sensitivity to output capacitance; TI recommends R_L ≥ 5 kΩ for stable operation per SBOS122E Section 7.3.2.

Is the INA168NA/250 pin-compatible with the INA138 series?

Yes, the INA168NA/250 shares identical pinout, package (SOT-23-5), and footprint with the INA138 series. However, the INA138 is rated for 36 V max common-mode and supply, whereas the INA168NA/250 supports up to 60 V-making them mechanically interchangeable but electrically distinct in high-voltage applications.