Part Number: INA138NA

Manufacturer: Texas Instruments

Description: IC Current Monitor 0.5% SOT23-5

Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of INA138NA/250

Datasheet  INA138NA/250 datasheet
Category Integrated Circuits (ICs)
Family PMIC – Current Regulation/Management
Manufacturer Texas Instruments
Packaging Tape & Reel (TR)
Part Status Active
Function Current Monitor
Sensing Method High-Side
Accuracy ±0.5%
Voltage – Input 2.7 V ~ 36 V
Current – Output
Operating Temperature -40°C ~ 125°C
Mounting Type Surface Mount
Package / Case SC-74A, SOT-753
Supplier Device Package SOT-23-5

INA138NA/3K Introduction

Unlock the Power of INA138NA: Your Full High-Side Current Shunt Monitor Solution

Find out how the INA138NA and INA168 (INA1x8) are changing the game. These high-side, unipolar current shunt monitors are changing the way accurate current measurement is done. With a wide common-mode input voltage range, low idle current, and a small SOT-23 package, these devices can be used in a wide range of applications. In our complete guide, you’ll learn how to bring out their full ability.

What is a current shunt monitor?

A current shunt monitor is a special piece of electronic equipment used to measure the amount of current in electronic systems. It works with the help of a shunt resistor, which is put in the path of the electricity. Since the drop in voltage across the shunt resistor is related to the amount of current going through it, it can be used to measure the amount of current.

Accurate current measurement and monitoring

Accurate current measurement and tracking are very important in a number of situations, including:

  • System Performance Optimisation: Current is a very important part of many electronic systems, such as those that handle power, motors, and batteries. Engineers can improve the performance of a system by making sure that currents are within the ranges they want and that it isn’t overloaded or underused.
  • Power Efficiency: Keeping an eye on the current helps you get the most out of your power. By measuring current consumption very carefully, engineers can find places where power is being wasted, take steps to save energy, and improve the general efficiency of the system.
  • Fault Detection and Protection: Unusual currents can show that something is wrong with a device. By keeping an eye on the current levels, engineers can find situations where there is too much current or a short circuit. This sets off safety measures that keep components or circuits from getting damaged.
  • Safety: In some uses, like electric vehicles or industrial equipment, it’s important to measure current accurately to make sure it works safely. By keeping an eye on the current, any dangerous situations can be found and fixed quickly. This keeps users safe.
  • System Diagnostics and Troubleshooting: Accurately measuring current is a useful diagnostic tool that can be used to figure out what’s wrong with a system. By looking at current patterns and how they change, engineers can find trouble areas, find broken parts, and make debugging easier.

Overall, reliable current measurement and monitoring are needed to improve system performance, save power, keep people safe, and make it easier to find and fix problems. Current shunt monitors like the INA138NA and INA168 let engineers get the most out of their computer systems by letting them measure current accurately.


Wide Input Common-Mode Voltage Range: Both the INA138NA and the INA168 have a wide input common-mode voltage range, which lets them work well even when measuring current on top of a high common-mode voltage. This function gives you flexibility and makes it work with different ways of setting up your system.

Low Quiescent Current: The INA138NA and INA168 both have low quiescent current, which means they use the least amount of power and save the most energy. This is especially helpful in battery-powered systems or other situations where power loss needs to be kept to a minimum.

Small Form Factor: Both the INA138NA and the INA168 have a small form factor. The INA138NA comes in a small SOT-23 package, and the INA168 can come in a DIP or SOIC package. This makes it easy to put them into designs with limited room, which makes them good for uses where size and weight are important.

Engineers can use the INA138NA or INA168 because of their wide common-mode input voltage range, low idle current, and small size. These qualities make it possible to measure current in a wide range of high-side applications in an accurate and efficient way, which improves the performance and reliability of electronic systems.

INA138NA/3K Key Features and Specifications

Wide Input Common-Mode Voltage Range: The input common-mode voltage range for the INA138NA and INA168 is usually from -0.3V to VCC + 0.3V. Because of this, they can handle high common-mode voltages, which makes them good for situations where the current being measured is added to a high voltage level. It’s flexible and works with a wide range of system setups.

Low Quiescent Current: Both the INA138NA and the INA168 have a low quiescent current, usually around 60 A.Quiescent current is the amount of current that a gadget uses when there is no load connected. Because these gadgets use less power when they are not doing anything, they can be used with batteries. It helps the battery last longer and generally uses less energy.

precision and linearity: The INA138NA and INA168 measure current with high precision and good linearity. They have a low offset voltage and a low gain error, so they can measure current accurately and reliably.

Wide Bandwidth: These devices have a wide bandwidth, which is usually between a few kHz and a few MHz. This lets them correctly measure currents that change quickly and record dynamic current events in real time.

External Gain Configuration: The INA138NA and INA168 can be set up with external gain configuration, which lets users change the gain of the current measurement to meet their own needs. This allows the sensitivity and resolution to be optimised based on the needs of the programme.

Frequently Asked Questions (FAQs)

● Can I measure AC currents with the INA138NA or INA168?

No, these tools are made to measure DC currents that only flow in one direction. You can’t use them to measure AC currents.

● What is the maximum voltage that these gadgets can handle in common mode?

Most of the time, the INA138NA and INA168 can handle common-mode values between -0.3V and VCC +0.3V. But if you want to know the exact specs, it’s best to look at the manual.

● How do I figure out the output voltage if I know the current?

The formula Vout = (Ishunt * Rshunt) * Gain can be used to figure out the output voltage, where Ishunt is the recorded current, Rshunt is the value of the shunt resistor, and Gain is the current shunt monitor’s gain setting.

● Can I change the INA138NA/INA168’s gain while it is running?

No, a constant-gain resistor is usually used to set the gain of these devices from the outside. During operation, the gain cannot be changed on the fly.

● Should I be careful about anything when I’m making the PCB plan for the INA138NA/INA168?

To reduce noise and interference, it is important to keep signal traces and sensitive analogue components away from traces that carry a lot of current or have a high frequency. Follow the planning suggestions for the PCB that are given in the device datasheet.

● Can I use the INA138NA or INA168 for apps that use a lot of current?

Yes, these gadgets are able to measure high currents. But make sure that the device’s highest current rating is not exceeded and that the right steps are taken to get rid of heat.


The INA138NA and INA168 are high-side, unipolar current shunt monitors with a wide input common-mode voltage range, low idle current, and small SOT-23 packaging. These gadgets are great for a wide range of uses because they can measure current accurately. They improve system performance, save power, make sure the system is safe, and allow designs with limited room. Explore the possibilities of the INA138NA and INA168 in your projects to see how they can help you measure current accurately. Contact ICRFQ, a trusted seller of electrical parts in China, to find out more or to place an order.

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