Rigol MSO1000z Pulse Output - Page 1
Forum section: electronics / testgear

author: 9tenths
author_rank: Newbie
timestamp: January 05, 2021, 02:56:16 pm
content: Noob question here...I am trying to configure Source1 on my Rigol MSO1000z to output a 0 to 3.3V pulse waveform. In the source menu, I have selected 'Pulse' with an amplitude of 3.30Vpp and an impedance of HighZ. The maximum offset the scope will allow me to select is 850mV (trying to go higher than that gives me a Parameter Limited error). I could very well be missing something here, but to get the waveform that I want, I need to set the offset to 1.65V. Does anyone know why this happening and how to configure the output to get the waveform I'm looking for?

author: hexreader
author_rank: Frequent Contributor
timestamp: January 05, 2021, 03:21:00 pm
content: Maximum output is +2.5 Volts, minimum is -2.5 Volts.There is no way to get a higher voltage than 2.5V whatever you do.I rarely use the sig gen in this scope for exactly this reason. You simply cannot generate useful signals for micro-controller use.

author: Martin72
author_rank: Super Contributor
timestamp: January 05, 2021, 03:35:13 pm
content: For elder printed circuit boards, which really need CMOS level (15V), we use this one here:https://www.tequipment.net/TTi/WA301/Waveform-Amplifiers/Pros are the relative low price and small form factor and of course the output of max. 30Vpp.Cons are permanent on after plug in the mains (no switch) and the Bandwith of 1Mhz.

author: Fungus
author_rank: Super Contributor
timestamp: January 05, 2021, 03:37:30 pm
content: The manual says this:Using the formula: 2.5V - (3.3V/2) = 850mV

author: Fungus
author_rank: Super Contributor
timestamp: January 05, 2021, 03:40:08 pm
content: Quote from: Martin72 on January 05, 2021, 03:35:13 pmHow does that answer a question about a MSO1000Z ?

author: Martin72
author_rank: Super Contributor
timestamp: January 05, 2021, 03:41:00 pm
content: Seriously?

author: Kean
author_rank: Unknown
timestamp: January 05, 2021, 03:59:31 pm
content: Yep, a limitation of the Rigol. You might be able to get away with just a 0-2.5V swing for your pulse waveform? It depends on the device you are driving with it.Alternatively you could use a small buffer circuit on the signal - e.g. 74HC logic such as 74HC125 breadboarded and powered from 3.3V, or maybe an OpAmp circuit with a gain of 2 or 4. A simple little project that is very useful to enhance the waveform gen.Juntek and Feeltech sell similar waveform power amplifiers to the TTi mentioned by Martin72 but at a lower price point which again may be useful for a hobbyist. Prices depend on bandwidth.

author: Martin72
author_rank: Super Contributor
timestamp: January 05, 2021, 04:01:49 pm
content: QuoteOh, interesting!

author: Kean
author_rank: Unknown
timestamp: January 05, 2021, 04:05:09 pm
content: There are a few posts here about them - Juntek DPA-1698 or DPA2698, Feeltech FPA-301e.g.https://www.eevblog.com/forum/testgear/juntek-dpa-2698-10mhz-signal-amplifier-digilent-analog-discovery/andhttps://www.eevblog.com/forum/testgear/whats-inside-a-feeltech-fpa-301-better-than-juntek-dpa-2698/Overkill for OP use case, but a useful device nonetheless.I've currently got a DPA-2698 on order from AliExpress along with a Juntek PSG9080. Just to full the gap between my other HP & Rigol AWGs.

author: 9tenths
author_rank: Newbie
timestamp: January 05, 2021, 05:09:51 pm
content: Thanks for all the great information and suggestions!