Blog Entries

QA350 gets True RMS

QA350 gets True RMS

by site admin
The QA350 thus far has been a high-resolution DC volt meter, with a bandwidth of 1.1 Hz (slow sampling) or 441 Hz (fast sampling). Release 1.70 cha...
A CMOS Pre-Amp for Hi-Z sources

A CMOS Pre-Amp for Hi-Z sources

by site admin
A few posts back we took a look at the challenges of measuring high-Z sources with audio analyzers than have a bi-polar based front-end. The big tr...
User Weighting and RIAA

User Weighting and RIAA

by site admin
A new feature in release 1.6 allows you to specify an arbitrary user weighting to the displayed data. This came as a request from those that are us...
Input Current Noise Density

Input Current Noise Density

by site admin
One of the new features in the QA401 1.6 release is the ability to display noise density. A user was curious why the noise density calculations cou...
Characterizing LDOs: Part 1

Characterizing LDOs: Part 1

by site admin
This is Part 1 of 3 parts.Part 2 of this article is located here.Part 3 of this article is located here. LDOs might seem to be interchangeable. An...
Quick Look: A Generic TPA3255 Design

Quick Look: A Generic TPA3255 Design

by site admin
This time, we purchased a TPA3255-based no-name class D amp that is commonly seen on E-bay or Amazon for around $60 or $70.
ASIO and Hypermiling THD

ASIO and Hypermiling THD

by site admin
Hypermiling is the act of driving a car with extreme efficiency so as to maximize the miles per gallon achieved. It requires a careful understandin...
Swept Measurements

Swept Measurements

by site admin
The QA401 software supports the ability to make swept measurements. You can even write your own measurements in DotNet (C++, C# or Visual Basic) an...
Simple Isolated +/-15V Split Rail

Simple Isolated +/-15V Split Rail

by site admin
There are a lot of solutions out there for generating split +/-15V from a single DC voltage, but all are lacking in some way or another. Either the...
QA401 and USB Noise

QA401 and USB Noise

by site admin
The QA401 relies on USB power. This is a great convenience because it means setup and making a measurement is quick and easy. But not all USB power...
QA401 Update 1.50

QA401 Update 1.50

by site admin
We’ve had some features in the queue for a while on the QA401 that made it out in the 1.50 release. Remember, the goal with the QA401 isn’t the be-...
Ultra-low Current Measurements with the QA150

Ultra-low Current Measurements with the QA150

by site admin
This post looks at how the QA101B Mixed Signal Oscilloscope and QA150 High Side Current Sense Amp can be used together to help the engineer underst...