USB Power Delivery Tester

USB Power Delivery specification

Was it USB power delivery?

USB-PD (PD stands for Power Delivery) is a universal standard. Devices can request capable currents and supply voltages from compatible USB PD hosts. Understand a phone can request a power of 15 W, listen to a laptop change 45 W.

Was it Quick Charge 4?

Fast charging is a proprietary charging protocol developed by Qualcomm and used to manage the power supply of a number of belongings via USB. This is checked, compensated for these devices with the power supply, which negotiate a fast and increased voltage, has led to faster charging. Fast Charge 4+ is the Lastet version of this technology and carries 3V-21V at 100W (20V / 5A).

Was it PPS?

The PPS function enables incremental rights of voltage and current. With PPS, the adapter can have a variable output voltage, compensate for communication with the device to be charged and thus optimize the charging conditions for each device.

What are e-markers in USB cable?

An E-marked cable is a USB Type-C cable that uses a marking chip to indicate cable pulling rights, e.g. its current carrying capacity, its performance, identification of the supplier, etc. E-known chips are required if:

• The current through the cable follows 3A
• The data must take care of 5 Gbit / s
• alternative modes are required

Specification

• Passmark Power Delivery Tester User Manual
• Download PDTest Application

• USB Power Delivery Tester PM125
• A 1 meter (39inch) USB B (male) to USB A (male) cable. This cable is used to connect the tester to a PC.
• A 40cm (15inch) E-Marked 5A USB Type-C TO Type-C cable. This cable is used to connect the tester to a Type-C USB power source (USB port or wall charger).
• A 40cm (15inch) USB TYPE-C TO USB A (male) cable. This cable is used to connect the tester to a Type A USB power source (USB port or wall charger).

Can I run multiple testers at the same time on one PC?

Yes, you can run multiple testers on one PC. You'll need a USB port per unit. For each unit connected you need to run a separate instance of the software.

Is there a protocol analyzer in the PC software?

No

Can the unit dissipate 100W continuously?

Continuous 100W power dissipation is right at the limit of the fans and heat sink to dump the heat without internal overheating. To be sure it will work, the tester needs to be in cool environment (e.g. 21C) and have some additional airflow across the unit. The unit will auto-shut down if the heat sink temperature reaches 75C, or the internal MOSFET junction temperature reaches 150C. 60W continuous should be possible is nearly all environments.

Is PD3.0 supported?

Yes, we support USB Power Delivery 3.0 for fixed power profile selection.

Does the tester support Programmable Power Supply (PPS)?

Programmable Power Supply (PPS) is one of additions to the USB-C Power Delivery 3.0 standard. A power supply’s output voltage can be programmatically adjusted in small increments (20mv) over its advertised range. The tester doesn't support PPS at the moment due to the need for additional hardware. We had PPS in our list of requested features and have just resleased a newer model (PM125) which supports PPS, shipping early January 2020.

Does the tester support Quick Charge (QC)?

Quick Charge is a Qualcomm’s proprietary technology which allows for the charging of battery powered devices at levels above and beyond the typical 5 volts and 2 amps. QC1, QC2, QC3, QC4 and QC4+ are supported in the new model (PM125) which has just been released, shipping in early January 2020.

Is there a Linux driver for the device?

Not at this time. But see the details about the API below. The device can also be used stand alone without any conenction to a PC.

Is there an SDK / API to use the device from my own software?

Yes. There is a protocol guide showing the commands required to control the to the device and example soure code (in C++ on Windows). See the USB PD Download page for details.

Does the device need to be connected to a PC?

No. You can use the device in a standalone manner. A standard 5V USB power supply is required however, additional functionality such as graphing is available in the PC software however.

How many power profiles can be displayed / selected?

A maximum of 7 profiles (depending on what the device under test supports)

What voltages are supported?

Any voltage between 5V to 20V can be used (depending on what power profiles the device under test supports).

Can I force an overcurrent situation?

Yes, from the PC software you can override the limit advertised by the device. This can simulate a badly behaved / faulty USB device. This can be useful if you are an electrical engineer designing a charging device and need to test the safety of the USB charger. WARNING: While the expected behaviour of USB chargers is to shut down in an over current situation, this might not happen. The consequences of which might be a catastrophic failure of the device under test. Including smoke, fire, short circuits and electrocution hazards.

I get an error message "Rotate Connector" what does this mean?

In theory, the USB Type-C connector is reversible, but the older USB3 port (use for the downstream loopback port link) is not reversible. There is a supporting logic in the USB PD tester to identify whether the Type-C cable is flipped or not. When the loopback port is enabled, the tester will identify the orientation but needs a multiplexer to forward the active USB3 lines to the Loopback port. The tester lacks such a switch, and therefore the cable should be manually flipped from the device side. This will allow the type-c data lines to connect to the USB3 data lines. The reason we didn’t include this switch was that it degrades the signal integrity (switch itself and the extra two ESD protection chips) and also makes our device more susceptible to ESD shocks. Note that this Rotate Connector message only appears when the "Loopback Port" option is enabled, so if you don’t have a device connected to the loopback port, you can disable the "Loopback Port" and as result the tester won’t be sensitive to the orientation.

How can I measure the capacity of USB power banks?

To measure the capacity of a USB power bank or battery pack, first make sure that the battery is fully charged. With the USB Power Delivery Tester switched on and connected to a monitoring machine with the monitoring software running, first click the "Reset Capacity" button in the user interface. Then, connect the power bank to the USB Power Delivery Tester. Then, set the current to a value that fairly demonstrates the power bank's capabilities (e.g. 1000mA or 1500mA). The current can be set precisely using the USBPD Test software user interface. Note that it is not necessary to set the current to the maximum advertised current as higher currents can result in more heat dissipation which will reduce the efficiency of the power bank's output. Then, leave the device running until the voltage is zero. Note that this could take more than an hour. Once the voltage is zero, the powerbank has been fully depleted. Take note of value displayed under "Capacity". The value is given in mAh (milliamp hours). As an example, a capacity value of 2000mAh produced with a current of 1000mA would indicate that the powerbank delivered for a total of 2 hours, and a capacity value of 2250mAh produced with a current of 1500mA would indicate that the powerbank delivered for a total of 1.5 hours. 

Is calibration required?

No calibration is possible in the current software / firmware release. We check the units during production and there aren't really any components that drift out of calibration. So no calibration should be required. If confirmation of the accuracy is required, then we would suggest splitting open a USB cable and measuring the Volts and Amps with a quality multimeter.

Can I test USB Type-C cables using the USB Power Delivery Tester?

Yes, using the USB Power Delivery Tester in conjunction with a Passmark USB3 loopback plug, you can test USB Type-C cables to check the quoted current, voltage drop and data integrity over the cable.

Tools needed

• A USB Power Delivery Tester
• USB3 loopback plug
• A desktop computer with a USB Type-C port (PD support).

The current rating of the Type-C port should be higher than the current capability of the cable being tested.

Set up the test environment

• Power up the USB Power Deliver Tester by connecting the analysis port to the computer
• Attach a USB3 loopback plug to the loopback port of the USB Power Delivery tester
• Run the USBPDTest application
• Enable the loopback port from the Configuration window
• Make sure Current Limit is set to "Enforce Limits"
• Run the USB30Test application
• Select loopback testing and enable the "Check Bus Error" option from the configuration window

How to test a cable

Test the Power Delivery communication

• Connect the USB host port to the "the Device Under Test" port using the USB Type-C cable that need to be tested. If the "Rotate Connector" message appeared on the tester's LCD, flip the cable from where it is attached to the "Device Under Test" port.
• Check the advertised profiles in the log window. You should be able to see all the port power profiles with the current level equal or less than the cable current rating.

Check the maximum voltage drop

• Find the voltage level that corresponds to the highest available current and select it from the "Voltage" drop down list
• Wait for "Port capability changed" message to appear in the log window. This means that the PD communication has been successful and the new profile is selected and provided by the port.
• Move the slider to the maximum current and check the voltage to make sure the voltage remains within the specification. If voltage goes outside the valid range, a log line with red color will appear.

Check data integrity

• On the USB30Test application, click on the "Start" button and monitor the log window to make sure the communication is error-free. The test should run at least for 10 seconds and at the end of the loopback test no error should be reported.