14 June 2016

Just the FAQs: Waveform Averaging

The upper grid displays raw samples directly from the ADC; the lower grid displays the average of 1000  acquisitions.
Figure 1: The upper grid displays raw samples directly from
the ADC; the lower grid displays the average of 1000
acquisitions.
If you've poked around the Teledyne LeCroy website, perhaps you've run across the extensive (and growing) collection of test-related tidbits we call our FAQ Knowledgebase. To highlight some of these helpful hints for making better use of your oscilloscopes, protocol analyzers, network analyzers, etc., we'll post some here on the Test Happens blog from time to time.

02 June 2016

USB Type-C and Dual-Role Port Devices

This protocol analyzer capture shows how a DRP alternates between voltage source and sink until it sees one  or the other at the far end of a link
Figure 1: This protocol analyzer capture
shows how a DRP alternates between
voltage source and sink until it sees one
or the other at the far end of a link
At this juncture in our ongoing series of posts about USB Type-C and power delivery, it's time to acknowledge that some Type-C devices are not strictly a power source or sink. Some are called out in the Power Delivery 2.0 specification as dual-role port (DRP) devices that may act as either a source or sink for power. Note that unlike in the original OTG spec, this applies only to a port's power role, not to being a USB host or connected device.