PicoScope 5000 (5444) Review

If you check out my older blog post, you’ll see a very detailed review of the PicoScope 6000 series device. I also had a chance to use a 5000 series device, specifically the 5444.

The 5444 is a 4-channel scope with a built-in AWG. The sample rate is up to 1 GS/s in ‘normal’ mode, but you can use something called Equivalent Time Sampling (ETS) to boost that up to 10 GS/s in specific cases.

Even if you are looking at the 5000-series device, you should check out my review of the 6000-series one because I won’t repeat everything I covered in that review.

Hardware, etc

The 5000 series is a pretty compact device, so handy if you’ve either got minimal desk space OR if you need to travel with it. You can use USB-only power for a limited number of channels, but I found it easier to just always use the power brick. The power brick is fairly small – it looks like the one on a normal USB hub.

Whilst the 6000-series device comes with nice spring-loaded scope probes, the 5444 device comes with you standard scope probes. If you really wanted the spring-loaded scope probes, you could of course buy them separately.

Important Features

Again you should check out the 6000-series review to see a discussion of features common to all PicoScope devices. I do want to point out three important features on the 5000-series device.

Bits for All

The first is specific to the 5000-series device, and this is the ability to switch between 8/12/14/15/16 bits on the ADC input. There’s some restrictions there – for example if you want 16 bits, you can only use a single input channel. In addition the sample rate decreases to 62.5 MS/s at the 16-bit range.

It’s important to realize this is different from ‘software resolution enhancement’ which most scopes have. You are actually changing the sampling resolution of the ADC. As an example of why this can be handy, see an example of me using the PicoScope differentially:

Or another example of me testing a switching PSU:

External Channel In

Like most scopes, the PS5000 series includes an ‘ext in’ channel. This ‘ext in’ doesn’t display on the screen, but can be used for triggering. Specifically this means your trigger channel then doesn’t count against your ‘ADC Channels’. So if you want to use the 16-bit range which means you only get one ADC channel, you can still have another channel as the trigger. Or if you need the full sample rate on one channel, but want to trigger on another.
On the PS5000 this input is on the ‘front panel’ of the scope. If you’re switching your measurement setup a lot, this is a nice convenience.

FFT Options

If you want to do FFT analysis, the 8/12/14/15/16 bit resolution options can be very handy for a better dynamic range. Here’s an example of different resolutions on a FFT:

These errors will exist on any scope, and are improved by higher resolution. You can simulate these yourself to see how even a pure sine wave is corrupted:

While I’m talking about FFTs: it’s worth mentioning the PicoScope has a huge FFT length. This is handy because remember when doing the FFT to use the scope as a ‘spectrum analyzer’, you are always starting from 0Hz. Thus if you want to measure the bandwidth of a narrow-band signal at 23MHz, you will always need to cover the ‘useless’ range from 0-22MHz. If you’ve only got a 2048 point FFT, this means by the time you ‘zoom in’ on the bandwidth of interest, you’ll have very poor resolution. Here’s an example:

Equivalent Time Sampling (ETS)

The 5444 device does support ETS, which can be used for measuring repetitive signals. As an example here is me sweeping a sine wave along past the 200 MHz analog bandwidth, and note when I enable ETS how the signal improves:

If you check out the PicoScope 6000 review, there’s a bunch more demos of where ETS can be useful!

Quick Conclusions

As mentioned, check out the PicoScope 6000 review for a lot more details of features common to the PicoScope series, including the AWG, the Software, and digital decoding.

The 5000 series is unique due to the ability to increase the hardware ADC resolution. You do run into issues where the standard 8-bit resolution is simply not cutting it. However you rarely want to purchase a higher-resolution scope due to the lower sampling speed, so the dynamic adjustment of resolution is an excellent option here, since you can just enable it when you require that higher resolution. For normal operation where you want maximum sampling rate, you can just leave the system on 8 bits.

Pros

1. Dyanmic adjustment of ADC resolution – see use-cases I posted in my videos.
2. Huge FFT length – handy for real-world scenarios where you want high frequency resolution. Again remember your FFT always starts at 0 (unlike a spectrum analyzer) & spans at least until your frequency of interest.
3. Fairly small, light-weight. Can use USB power in some circumstances avoiding need for power supply, although supply is fairly small.
4. Huge buffer size
5. API Provided, Python library in-progress for super-simple scripting
6. Decodes huge amount of serial protocols & no need to purchase add-ons
7. ETS Mode can be used to give you a faster scope than you would otherwise have in certain situations. Very useful for problems such as phase measurements, which don’t have a huge analog bandwidth, but just need the time resolution.
8. The ‘Ext In’ is on the front side, which makes it easier to use. The ext in gives you a channel dedicated for triggering on, and lets you ‘save’ the ADC channels for actual signals.

Notes

1. Standard scope probes – nothing wrong with them, but nothing special
2. No carrying case provided – considering portability, would be handy to have something like plastic ‘cover’ fitting over all BNC connectors, so you could slip this into your computer bag without worrying about damaging the interior part of the BNC connector. Or even just buy 6x BNC connector dust caps (<$1/each off ebay or similar). PicoTech sells a case it looks like if you wanted one too.
3. USB Ground connected to scope probe ground – should be careful not to have voltage difference between them, or I doubt your scope will be happy. The ‘real’ scopes I’ve tested seem to have all their probe grounds connected to Earth (based on two Agilent ones). So I don’t list this as a ‘con’ for the PicoScope, as it’s basically the same issue.

Cons

1. Cannot trigger on serial protocols
2. Software seems to be missing ‘standard’ feature of average last N traces together in real-time. (NB: This is supposed to be added shortly)