PICOSCOPE 2204A -  USB Oscilloscope - Review

Table of contents

RoadTest: PICOSCOPE 2204A -  USB Oscilloscope

Author: ljakes

Creation date: 25 Oct 2017

Evaluation Type: Test Equipment

Did you receive all parts the manufacturer stated would be included in the package?: True

What other parts do you consider comparable to this product?: null

What were the biggest problems encountered?: null

Detailed Review:

Introduction:

Thanks to Element 14 for the opportunity to thoroughly test this product to the best of my capability with the support test equipment and test aids that I have at hand.  In this review I am installing and operating the PicoScope 2204A PC Oscilloscope.  I am demonstrating its capabilities by analyzing the performance of a TDA2030A Single Chip Amplifier Module.

Hardware /Software:

This is the product I received:

Which included:

1 - PicoScope 2204A PC Oscilloscope

1– USB Cable

2 – M1007 60 Hz Oscilloscope Probes

1 – PicoScope 6 Software CD

1 – Quick Start Guide

1 – “An Introduction To PC Oscilloscopes” Poster

These are items used that I had on hand:

Which included:

1 – 10 ohm 10 Watt Variable Resistor

1 – 1to1 Oscilloscope Probes

1 – TDA2030A Amplifier Module

1 – Alligator Clips/Cable

1 – 9 volt Battery

A Closer Look at the TDA 2030A Amplifier Module.

I used a PC with a Phenom II X3 2.8 GHz CPU and 6 GBytes RAM running Windows 7 Professional.

Discussion:

Following the instructions in the Quick Start Quide, I connected the USB Cable, inserted the Installation CD and installed the software. There were no problems and everything was up and running within minutes.  I used the Oscilloscope mode for this review.

I then calibrated each probe by connecting each of them to the signal generator output set to output a 1 kHz 100mV squarewave and the PC Oscilloscope channel controls and trigger mode set to Auto as shown below:

The following screenshot demonstrates Channels A and B superimposed waveforms with the signal generator connected and set to 1 kHz, 1 Volt peak sine wave.  These signals display very nice and sync’d.  The signal generator will also output a triangle, ramp up and ramp down simple signals. 

The following screenshot demonstrates Channels A and B split screen wave forms with the signal generator connected and set to 1 kHz, 1 Volt peak sine wave.  These signals again display very nice and sync’d. 

I connected the variable resistor, set to 8 ohms, to the output of the TDA2030A Amplifer.  I connected the input of the TDA2030A Amplifier to the output of the PicoScope signal generator.  I connected the output of the TDA2030A Amplifier to Channel B of the PicoScope and Channel A to the input to the Amplifier.  I powered the PDA2030A with a 9-volt battery. 

As illustrated below:

I set the PicoScope to present a split screen Channel A and B display and set the Amplifier for a minimum input of 20 mV peak Sine Wave at 1kHz.  It seems that any amplitude less than 20 mV produces a very jittery display.

The resultant presentation is illustrated below:

This shows an amplification of about 4x through the amplifier with very good stability and symmetry.  Also the display seems to reveal some switching points of the generator at every 90 degree increment!

Next I changed the signal generator to a triangular wave with the resultant presentation illustrated below:

Again, an amplification of 4x is shown with very good stability and symmetry with the 90 degree switching points evident.

Next I changed the signal generator to a square wave with the resultant presentation illustrated below:

Again, an amplification of 4x is shown with very good stability and symmetry.  This time the PicoScope reveals some ramping error being produced by the amplifier.  This display now allows one to actually measure the exact error pattern that the TDA2030A Amplifier produces when processing a square wave!

Next I changed the signal generator to a ramp up wave with the resultant presentation illustrated below:

Again, an amplification of 4x is shown with very good stability and symmetry with the 90 degree switching points evident.

Next I changed the signal generator to a ramp down wave with the resultant presentation illustrated below:

Again, an amplification of 4x is shown with very good stability and symmetry with the 90 degree switching points evident.

Next I changed the signal generator back to sine wave, adjusted the amplifier to max and adjusted the signal generator for an amplitude that presents the maximum amount of undistorted output of the amplifier.  The signal generator is thus set at 56 mV peak.

The resultant presentation is illustrated below:

Now an amplification of 33x is shown with very good stability and symmetry but with hardly the 90 degree switching point error being displayed.  It now seems evident that the PicoScope 2204A exhibits a small signal switching error in its output at levels below around 50 mV!

Next I changed the display to overlay channels A and B, increased the signal generator to 10 kHz and reduced the Amplifier Amplitude Adjust for proper display.

The resultant presentation is illustrated below:

Now an amplification of 3.5x is shown with good symmetry being analyzed more closely.  The display, however, is now starting to show some jitter.

Next I changed the display back to split and increased the Amplifier Amplitude Adjust back to maximum.

The resultant presentation is illustrated below:

Now an amplification of 34x is shown with good symmetry and jitter becoming evident.

Next I changed the signal generator frequency to 100kHz, which is the maximum of the PicoScope.

The resultant presentation is illustrated below:

Now an amplification of 35x is shown but with some distortion in both channels.

Next I changed the signal generator back to 1 kHz and increased the amplitude until the output began to clip.  The signal generator is set at 65 mV Peak.

The resultant presentation is illustrated below:

Now an amplification of 33x is shown but with some clipping.

Next I adjusted the signal generator to exhibit severe clipping.  The signal generator is set at 92 mV Peak.

The resultant presentation is illustrated below:

Now an amplification of only 24.5x is shown with severe clipping.  The limits of the Amplifier have been exceeded.

Lastly, in order to demonstrate and measure phase delay, I set the display to overlay, signal generator frequency to 50 Hz, signal generator amplitude to 100 mV Peak and adjusted the Amplifier gain to 2.3x.

The resultant presentation is illustrated below:

Now you can readily see that there is phase delay between the input (Channel A) and output(Channel B) waveforms.

Using the Phase and Vertical Rulers of the PicoScope the phase error can be measured as below:

Markers placed at the peaks of each wave and the end of channel B cycle allow the phase delay of the Amplifier to be measured.  In this case the phase delay of the TDA2030A Amplifier module at 50 Hz is 360-64.84 or  295 degrees.

CONCLUSION:

The PicoScope 2204A worked very well in fully evaluating the TDA2030A Amplifier Module.  I especially like how easily the Windows software loaded and performed.  The "Auto" features worked very well and gave you a quick and accurate starting point for viewing your waveforms.  Phase markers are also a great feature and useful in so many ways.

The only negatives aside from the fact that it is a PC based Oscilloscope and not as convenient to use as a  Stand Alone, is that people have reported having difficulties because the USB port is not ground isolated from the Probe and Generator Grounds and that in my experience it appears that the signal generator exhibits some switching error at low amplitudes below about 50 mV Peak.  However, these are only minor and the PicoScope is still superb.