AD and DA converter testing
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dScope Series III's ability to generate and analyze signals in both
analogue and digital domains allows easy testing of A/D and D/A
converter products. It can evaluate the audio performance of a
converter, together with characteristics of the digital interface. The
ability of the dScope to present analogue parameters in terms of
digital units (and vice-versa) makes it very powerful when testing
converter equipment – for example, the input to an A/D
Converter can be generated in dBFS.
| QUICK STARTS |
  DA converter test |
| RELEVANT PRODUCTS |
 dScope Series III |
| VSIO Adapter |
| dScope Series IIIE |
A/D Converters
Converters with AES3, SPDIF or TOSLINK outputs can be connected to the Digital Inputs of the dScope. dScope can perform high-performance audio measurements on the converter (for example, frequency response, noise, THD+N, cross-talk etc) as well as full analysis of the Digital Carrier, including display of an Eye Diagram or analysis of both fs and data jitter.
D/A Converters
The dScope’s Digital Outputs can be connected to the inputs of the converter using AES3, SPDIF or TOSLINK outputs. The high analogue performance of the dScope’s analyzer allows analysis of a converter to its full resolution. Again, full audio analysis can be performed, and the dScope’s extensive digital carrier options can be used to determine the effects of a poor carrier on converter performance. For example, parameters such as common-mode interference, jitter or long rise/fall times can be adjusted to see their effects on the performance of the converter.
Serial Digital Buses and Codecs
In many applications, the digital connection of an A/D converter or D/A converter is not easily accessible via a conventional S/PDIF, TOSLINK or AES3 interface, but traverses the PCB of the device on a digital serial bus. Using the VSIO Serial Interface Adaptor the dScope can connect directly into the bus, either from its generator or into its analyzer, making it possible to generate digital audio data directly onto the serial bus, or analyze audio data that is present on the bus with the full range of dScope audio measurement tools.
Windows Sound Devices
With the release of dScope Version 1.20 in May 2007, dScope gained the ability to directly interface with Windows Sound Devices, both as a generator and for analysis. This has made it possible to directly generate audio within the dScope application which is played out through a Windows sound device or receive audio data from a Windows Sound Device directly into the dScope application for analysis. The audio from Windows Sound Devices is received into the dScope application in the same way as the FFT sample buffers, so any measurements that can be performed using the dScope FFT Detectors can be performed on data from a Windows Sound Device. This makes it possible to measure Windows Sound Devices such as sound cards, USB Audio devices etc, directly from the dScope. It also makes it possible to measure with a sound card using the dScope software, although it should be noted that the dScope Software still requires the dScope hardware to be present to do this.
The outputs of many modern converters include a large amount of out-of-band noise which can be filtered out using the dScope's simple-to-use filter options. Digital power amplifiers are a special case of D/A converter, and the output of some of these can affect the auto-ranging of the input gain stages of test and measurement equipment. In this case our passive low-pass filter can be used to filter out these components before reaching the dScope.
App ID: 0001, Resource ID: 73