JETPERCH JOULESCOPE JS110 User manual

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Joulescope™ JS110 User’s Guide
Precision DC Energy Analyzer
Revision 1.0
Last revised 2020 June 27

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1. Affordable, easy-to-use, accurate and precise
Multimeter view
Oscilloscope view
Applications include:
•Microprocessor and microcontroller power profiling and optimization
•Hardware power optimization
•Sleep current optimization
•Hardware and software troubleshooting
•Software characterization and interrupt service routine profiling
•USB 2.0 inrush and suspend current pre-compliance testing
•General-purpose current, voltage, power, charge, and energy measurement
The Joulescope™ JS110 is the most affordable and easy-to-use precision DC energy analyzer. It
measures current and voltage, then computes power and energy. Many modern battery-powered
devices and IoT devices have a high dynamic current range, which makes accurate measurement
difficult. When “sleeping”the devices consume nanoamps (nA) or microamps (µA), but when active,
they consume milliamps (mA) or amps (A). Joulescope combines high-speed sampling and rapid
dynamic current range switching to provide accurate and seamless current and energy measurements,
even for devices with rapidly varying current consumption. The unprecedented accuracy and low-cost
of Joulescope allows every engineer on the team to measure the energy consumed by the target device
during development. Joulescope provides rapid feedback on how changes affect the overall product
battery life.
Joulescope displays instantaneous voltage, current, power, and energy, like a multimeter. The
multimeter provides a quick and easy summary of the present state of your device.
Joulescope displays waveforms of voltage and current over time, like an oscilloscope. This oscilloscope
view allows you to identify and to troubleshoot dynamic behavior and short events, including inrush
current, event handlers, and tasks.

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2. Key benefits
•Dynamic range: Joulescope accurately measures electrical current over nine orders of
magnitude from amps down to nanoamps. This wide range allows accurate and precise current
measurements for modern devices. Sleep modes are often just nanoamps (nA) or microamps
(µA). Active modes are often milliamps (mA) or amps (A).
•Low voltage drop: Most multimeters and current meters have a significant voltage drop
(sometimes called burden voltage or insertion loss), which affects the actual voltage delivered to
the device under test. Joulescope has a total voltage drop of 25 mV at 1 A, which keeps your
target device running correctly. Joulescope’s extremely fast current range switching maintains
low voltage drop even under rapidly varying current demands.
•Makes the invisible visible:Joulescopes measure current and voltage 2 million times per
second with 250 kHz bandwidth. This high sampling rate makes the power consumption of
interrupt service routines, inrush currents, and other short events visible.
•Easy to use: Joulescope reports cumulative energy consumption along with real-time current,
voltage, and power. The multimeter view clearly shows the most recent value, while the
oscilloscope view allows you to explore changes over time. Much simpler and more accurate
than anything in its class!
•Customizable: The Joulescope host software is open source on GitHub. You can also swap the
banana jack front panel with front panels that have other connector types. The front panels are
open source on GitHub.
•Portable: Joulescope fits in your backpack and only needs a small part of your desk. Take
Joulescope wherever you want to use it!
•Affordable: Joulescope is affordable and priced so that every developer on the team can have
one at their desk. With such convenient access, Joulescope allows developers to see the impact
of their changes on energy consumption immediately. Developers can make informed choices
to account for battery life during design. Eliminate power consumption surprises during final
product testing!

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3. Key features
•-1V to 15V voltage range
•-1A to 3A current range, continuous
•Up to 10A current pulses (<10 ms, < 3A average per second)
•Down to 1.5 nA resolution, equivalent to 32-bits of dynamic range
•Synchronously measures voltage and current at 2 million samples per second, 14-bit
•250 kHz bandwidth
•Rapid 1 μs switching between shunt resistors for seamless dynamic current measurement
•Computes power, total energy, and charge
•Operates with minimal voltage disturbance between IN and OUT ports
•Up to ±48V common-mode voltage between USB ground and IN-, IN+, OUT+, and OUT-
•2 general-purpose inputs and 2 general-purpose outputs
•Programmable on/off for power cycling the target device and measuring inrush currents
•USB 2.0 high-speed host connectivity
•Host software support for Microsoft® Windows®, Apple® Mac® OS X®, and Linux®
•Host software provides real-time graphs of current, voltage, and power over time
•Host software is open source and available on GitHub
•Swappable front panel with open-source designs on GitHub
•Firmware upgradable
See Section 8 for the full specifications.

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4. Table of contents
1. Affordable, easy-to-use, accurate and precise .....................................................................................2
2. Key benefits...........................................................................................................................................3
3. Key features ..........................................................................................................................................4
4. Table of contents ..................................................................................................................................5
5. What comes in the box.........................................................................................................................7
6. Meet Your Joulescope...........................................................................................................................8
7. Quick start.............................................................................................................................................9
8. Specifications ......................................................................................................................................11
8.1. Absolute maximum ratings.........................................................................................................11
8.2. Mechanical..................................................................................................................................11
8.3. Recommended operating conditions..........................................................................................11
8.4. Specification conditions..............................................................................................................11
8.5. Current measurement specifications..........................................................................................12
8.6. Voltage measurement specifications..........................................................................................12
8.7. General specifications.................................................................................................................12
8.8. Parasitic effects specifications....................................................................................................12
8.9. Software-controlled fuse specifications .....................................................................................12
8.10. General Purpose Inputs & Outputs.........................................................................................13
9. Host software......................................................................................................................................14
9.1. Installation ..................................................................................................................................14
9.1.1. Linux....................................................................................................................................14
9.1.2. Windows 7 ..........................................................................................................................14
9.1.3. macOS .................................................................................................................................14
9.2. Multimeter view .........................................................................................................................15
9.3. Oscilloscope view........................................................................................................................16
9.4. Energy and Charge......................................................................................................................19
9.5. Open-source................................................................................................................................19
10. Theory of operation........................................................................................................................21
10.1. Ammeter .................................................................................................................................21
10.2. Voltmeter................................................................................................................................22
10.3. Host Computer........................................................................................................................22
10.4. Power, Energy, Charge, and Statistics.....................................................................................22

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10.5. High impedance / low leakage................................................................................................23
10.6. Electrical isolation...................................................................................................................23
11. How to swap the front panel ..........................................................................................................24
12. GPI & GPO .......................................................................................................................................25
13. Electrical Isolation...........................................................................................................................27
14. Typical Behavior..............................................................................................................................28
14.1. Step Response.........................................................................................................................28
15. Compliance .....................................................................................................................................31
15.1. United States...........................................................................................................................31
15.1.1. FCC Notice...........................................................................................................................31
15.2. Europe.....................................................................................................................................31
15.3. Safety ......................................................................................................................................31
15.4. RoHS Directive 2011/65/EU, 2015/863/EU ............................................................................31
15.5. Country of origin .....................................................................................................................32
16. Maintenance...................................................................................................................................33
16.1. Verification Procedure ............................................................................................................33
16.1.1. Preliminary operations........................................................................................................33
16.1.2. Voltage Validation Process..................................................................................................33
16.1.3. Current Validation Process..................................................................................................34
17. Warranty.........................................................................................................................................37
18. Contact............................................................................................................................................38
19. Glossary...........................................................................................................................................39
20. User’s guide information ................................................................................................................41
20.1. Copyright notice......................................................................................................................41
20.2. Publisher .................................................................................................................................41
20.3. Warranty .................................................................................................................................41
20.4. Change log...............................................................................................................................42

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5. What comes in the box
Your Joulescope JS110 purchase includes:
•Joulescope JS110 instrument
•Banana Jack Front Panel, already installed
•6’ USB 2.0 A to B cable
•T15 Torx screwdriver
•Quick Start Guide
•Joulescope sticker
You will need to provide:
•A host computer which must be running Microsoft® Windows® 10, Window 7, Apple® Mac®
OS/X® or Linux®. Most computers manufactured within the last five years should work. The
computer requires an available USB 2.0 port, at least 500 MB of hard drive / solid state drive
storage space, and 1 GB of available RAM.
•Suitable cable(s) to connect Joulescope to your power source
•Suitable cable(s) to connect Joulescope to your target device.
You need an internet connection to download the free software.

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6. Meet Your Joulescope
The front side of Joulescope has the connectors that connected to your target device and its regular
power supply. Connect your power supply positive output to IN+, and connect OUT+ to your target
device’s positive voltage input. Connect the target device’s ground or negative voltage input to OUT-.
Connect IN- to your power supply ground or negative output.
The LED indicates when your Joulescope is ready to collect measurements.
The backside of Joulescope has the host USB connector, status LED, and GPIO connector:
Use the provided USB cable to connect the USB host computer connector to your host computer. The
status LED indicates when the Joulescope successfully communicates with the host computer. For
Windows hosts, the Status LED illuminates shortly after connecting the Joulescope to the computer. For
Linux and macOS hosts, the Status LED will not illuminate until the Joulescope software attempts to
connect.
The GPIO connector provides two general-purpose inputs and two general-purpose outputs. See
Section 12 for details.

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7. Quick start
Download the host software from http://www.joulescope.com/download. Follow the instructions on
the download page to install the software for your platform. Linux, macOS, and Windows 7 may require
additional steps. See section 9.1 for details.
Start the Joulescope host software.
Connect the Joulescope USB port to the host computer using the provided USB cable.
The host software will automatically detect the connected Joulescope and start displaying data.

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Connect the Joulescope IN port to your power source. If using a configurable power supply, set the
voltage and current suitable for your device under test. The maximum voltage between IN+ and IN-
should never exceed ±15V. IN and OUT are electrically isolated from USB, but the voltage between any
port and USB ground should never exceed ±48V.
Connect the Joulescope “OUT” port to the power input for your device under test.
Operate your device under test. The Joulescope host software starts in the Multimeter view by default.
Use the Multimeter view to measure the current, voltage, power, charge, and energy consumption.
Dive into more detail with the oscilloscope view. Select View →Oscilloscope Default to display
waveforms of voltage, current, and power over time.