Otii Arc Pro

High-precision energy consumption analysis & optimization tool.

The Otii Arc Pro is a compact and portable tool with comprehensive technical features for energy optimization of battery-driven and energy-harvesting devices. As a multi-purpose tool, it serves as a power supply, measurement unit, analyzer and debugger, making it the must-have addition for everyday use on any hardware, firmware and software developer’s desktop.

With Otii Arc Pro and Otii 3 Desktop App, you can source the voltage of the device under test (DUT) up to 5V while simultaneously measuring and recording current, voltage, and power data in real-time for further analysis to optimize battery life throughout the development cycle, supporting a sample rate up to 4ksps for main current channel, plus a wide dynamic current measurement range (nA-5A) with 5nA resolution, and accurate current measurement (±0.1% + 50nA) for currents below 19mA and (±0.1% + 150uA) for higher currents.

To elevate the Otii Arc Pro's capabilities for product development, test and verification, quality assurance, and maintenance, explore Otii Toolbox, a set of specialized licenses that can be purchased as perpetual or subscribed to on yearly or monthly basis.

Key benefits

  • All-in-one functionality: Otii hardware and Otii software integrates power supply, real-time monitoring, and detailed analysis in a single, compact, user-friendly product.

  • Quick installation & easy to use: Download Otii 3 Desktop app, plug the Otii Arc Pro to your device under test (DUT) and start measuring energy data in less than a minute.

  • Optimal power alternatives: Power up Otii Arc Pro based on your solution setup and power requirements via USB or an external DC adapter.

  • Versatile connection: Power source your device under test using the Otii Arc Pro, which can deliver up to 5V at high voltage/current resolution. The DUT can be connected either through its DC input or battery connectors.

  • Real-time measurements & analysis: Analyze and compare charts and measurements in real-time, covering currents, voltages, and power within the Otii 3 Desktop App – it allows scrolling, zooming, and selecting current consumption and debugging logs during measurement.

  • Continuous serial synchronization: Measurements are continuously synchronized with debug logs from the device under test via UART.

  • Responsive UI: Ensure smooth performance under heavy data measurements loads, supporting multiple streams and long recordings – optimized for high-definition displays to enhance user experience during analysis.

  • Collaborative features: Share recordings and analyses with team members to get insights and feedback for further product releases on a recurring basis.

  • Upgradeable software: Unlock a wider range of features and specialized functionalities, including battery profiling and automation tools.

Key features


Current and voltage measurement

  • ±(0,1% + 50nA) accuracy below 19mA and +-(0.1%+150uA) above 19mA

  • 5nA current measurement resolution

  • 24 bit ADC with automatic switching between ranges

  • No burden voltage

  • Voltage measurement accuracy ±(0.1% + 1.5 mV)

Sample rate

  • Up to 4ksps for main current channel

  • 1ksps for all other channels (main voltage, ADC current, ADC voltage, SENSE+, SENSE-, UART RX, GPI1, GPI2)

Power supply

  • 0.5V - 5.0V.

  • USB only (0.5V - 3.75V in auto range mode, 0.5V - 4.2V in high range mode)

  • DC plug supply (0.5V - 4.55V in auto range mode, 0.5V - 5.0V in high range mode)

  • -2.5A to 5A (depends on available current from USB or DC plug)

Digital interface

  • Digital IO voltage 1.2V - 5.0V

  • Max 10mA source and sink in total


  • Otii software support for Microsoft Windows, Apple macOS, and Linux Ubuntu.

  • Real-time graphs of currents, voltages, power measurements and digital inputs.

  • Analyze statistics and measurements while recording continues in the background.

  • Connect multiple Otii Arc Pro to manage and sync multiple recordings at the same time.

  • Record and manage multiple recordings for unlimited time.

  • Record and sync data with UART logs.

  • Customize recordings and channels names to make the change logs easy to trace during your solution's development cycle.

  • Save, load, and export projects as a zip-archive, or recording data as CSV for further analysis in collaboration with your team.

  • In-line and 4-wire measurement support.

  • Unlimited changes with undo/redo functionality.


Use Otii Arc Pro every day to:

  • Power your devices under development

  • Energy profile microcontrollers, sensors and devices in real-time and over time

  • Optimize sleep current and extend battery life

  • Design power-efficient hardware, firmware and software through regression testing

  • Troubleshoot your hardware, firmware and software

  • Sync UART logs with power measurements to see what drains the energy





15°C / 60°F

30°C / 86°F


30 %

60 %



Output voltage (auto range)

0.5 V

3.75 V

Output voltage (locked to high current range)

0.5 V

4.2 V

Output voltage setting resolution

Output current

250 mA

up to 1A ⁽¹⁾


Output voltage (auto range)

4.55 V

Output voltage (locked to high current range)

0.5 V

5.0 V

Output voltage setting resolution

1 mV

Output current, max continuous ⁽³⁾

2.5 A

Output current, max peak ⁽³⁾

5 A

PROGRAMMABLE CURRENT SINK (requires an Otii Toolbox)MinTypicalMax

Sink current

0 A

2.5 A

Sink current, setting resolution

39 µA

Sink voltage, USB power supply

0.85 V ⁽⁴⁾

4.2 V

Sink voltage, external power supply

0.85 V ⁽⁴⁾

5.0 V



±(0.1% + 50 nA)⁽⁵⁾

Sample Rate in ±19 mA range

4 ksps

Sample Rate in ±2.7A range

1 ksps

Sample Rate in ±5.0 A range

1 ksps

Analog bandwidth (3 dB)

400 Hz


Total accuracy

±(0.1% + 1.5 mV)

Sample rate

1 ksps

Expansion port



110 bps

5.25 Mbps

DIGITAL I/OMinTypicalMax

Digital IO operating voltage

1.2 V

Vio ⁽⁷⁾

5 V ⁽⁸⁾

VIL Low-level input voltage. VIL


VIH High-level input voltage


Imax, Max sink/source current (total for GPIOs)

-10 mA

10 mA

Differential ADC, pins ADC- and ADC+MinTypicalMax

Voltage input

0 V

5 V

Shunt voltage range

-81.9175 mV

81.2 mV


2.5 µV


±(0.1% + 10 µV)

Input impedance

220 kΩ

Single ended ADC, pins ADC- and ADC+MinTypicalMax

Voltage input

0 V

5 V


1.25 mV


±(0.1% + 7.5mV)

Input impedance

830 kΩ

SENSE, pins SENSE- and SENSE+MinTypicalMax

Voltage input

0 V

5 V


1.5 mV



Input impedance

1 MΩ


Output voltage

5 V

Output current

500 mA


DC JACKMinTypicalMax

Input voltage

7 V

9 V

Input current

5 A


VBUS voltage ⁽⁴⁾

4.75 V

5.25 V

VBUS current ⁽⁴⁾

3 A

⁽¹⁾ USB power capacity and reliability in laptops and desktops greatly depend on host USB port/cable design. ⁽²⁾ See list of recommended external power supplies and powered USB hubs at our FAQ. ⁽³⁾ Depends on chosen power supply. Otii Arc Pro will monitor internal temperature and cut off if temperature limit is reached. ⁽⁴⁾ Sink voltage can go below this specification if locked to high range. It is possible to go down to 0.5 V if the sink current is below 1.9 A. For currents below 19 mA, the measurement will have a lot more noise when locked to high range than in auto range. ⁽⁵⁾ Up to 19 mA current in auto range, for higher currents, the accuracy is ±(0.1 % + 150 µA). Average > 1s. ⁽⁶⁾ See Nexperia SN74LVC8T245 for details. ⁽⁷⁾ Expansion Port Digital voltage level is set by user in Otii SW. ⁽⁸⁾ Maximum voltage will depend on your USB power supply and USB cable. ⁽⁹⁾ See TI INA226 for details.

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