Texas Instruments INA168NA/250G4

Overview

INA168NA/250G4 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 delivers 200 µA/V transconductance, ±1 mV max offset voltage at 25°C, 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 supply and input voltages are independent.

For engineers reviewing the INA168NA/250G4 datasheet, INA168NA/250G4 pinout, INA168NA/250G4 application, or INA168NA/250G4 equivalent, key selection considerations include its 2.7 V to 60 V supply range, 25 µA quiescent current, 120 dB CMRR, single-resistor gain configuration, and compatibility with high-common-mode industrial and portable power systems.

Technical Context

The INA168NA/250G4 implements a high-voltage precision op amp with trimmed thin-film resistors and a low-noise output transistor, enabling accurate differential voltage-to-current conversion. Its input common-mode voltage (up to 60 V) is fully independent of its supply voltage (2.7 V to 60 V), supporting true high-side sensing without level-shifting circuitry.

It functions as a transconductance amplifier with fixed 200 µA/V gain (±1% typical), delivering output current proportional to (VIN+ – VIN–). Output compliance is governed by two limits: (V+) – 0.7 V – (VIN+ – VIN–) and VIN– – 0.5 V - both critical for stable operation in wide-input-range applications.

Key Specifications

Pinout & Package

INA168NA/250G4 is housed in a 5-pin SOT-23 (DBV) package measuring 2.90 mm × 1.60 mm, optimized for space-constrained PCB layouts in portable and embedded power systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with INA168NA/250G4, the INA240A1DR adds bidirectional capability at the cost of fixed gain and larger package, while the MAX4080TASA+ matches transconductance and voltage range but trades SOT-23 compactness for SOIC-8 thermal performance and pinout flexibility.

Availability

INA168NA/250G4 is available at Aetrix Electronics and suitable for battery chargers, industrial 48 V power rails, and portable medical device power systems requiring stable component supply, long-term lifecycle support, and guaranteed traceable sourcing.

Supply support for INA168NA/250G4 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, specializing in analog, embedded processing, and power management technologies for industrial, automotive, and communications markets.

The INA168NA/250G4 belongs to TI's high-side current shunt monitor product line, engineered specifically for accurate, low-power, high-common-mode current measurement in space- and energy-constrained systems.

FAQ

What is the maximum common-mode voltage supported by the INA168NA/250G4?

The INA168NA/250G4 supports an input common-mode voltage range of 2.7 V to 60 V. This specification is explicitly confirmed in the Recommended Operating Conditions table of the SBOS122E datasheet. The absolute maximum rating extends to 75 V, but sustained operation above 60 V is outside recommended conditions and may impact accuracy or reliability. The INA168NA/250G4 maintains full functionality across this 60 V range regardless of V+ supply voltage.

Does the INA168NA/250G4 require external components to set gain?

Yes - the INA168NA/250G4 uses an external load resistor (RL) connected between the OUT pin and ground to convert its 200 µA/V transconductance output current into a voltage. Gain is calculated as VOUT = (VIN+ – VIN–) × 200 µA/V × RL. No additional resistors or feedback networks are needed; RL alone determines system gain, enabling simple, predictable scaling from 1× to >100× depending on RL value (5 kΩ to 500 kΩ).

Can the INA168NA/250G4 measure bidirectional current?

No - the INA168NA/250G4 is a unipolar current shunt monitor designed only for positive differential input (VIN+ > VIN–). Applying reverse polarity (VIN– > VIN+) forces output current to zero without damage, but yields no usable signal. For bidirectional measurement, TI recommends using two INA168NA/250G4 devices in opposing configurations with external logic or a comparator, as shown in Figure 15 of the SBOS122E datasheet.

What is the quiescent current of the INA168NA/250G4 at 125°C?

The INA168NA/250G4 has a maximum quiescent current of 60 µA over the full operating temperature range of –40°C to +125°C, as specified in Section 6.5 of the SBOS122E datasheet. At 25°C, typical IQ is 25 µA, rising to ≤60 µA at 125°C. This low, well-bounded current enables reliable use in thermally demanding environments such as enclosed power supplies or automotive under-hood modules.

Is the INA168NA/250G4 pin-compatible with the INA138 series?

Yes - the INA168NA/250G4 shares identical pin configuration, function mapping, and SOT-23 (DBV) package dimensions with the INA138 family. Pin 1 is OUT, Pin 2 is GND, Pin 3 is VIN+, Pin 4 is VIN–, and Pin 5 is V+. However, the INA168NA/250G4 supports up to 60 V common-mode voltage versus 36 V for the INA138, and its absolute maximum ratings differ accordingly. Electrical behavior is otherwise functionally aligned, allowing drop-in replacement where voltage requirements permit.