Dual channel vs more Frequency Function generator? - Page 1
Forum section: electronics / beginners

author: Zx Spectrum
author_rank: Contributor
timestamp: January 02, 2018, 04:31:00 pm
content: i am a computer engineering student, totally new electronics; so far, i have been more inclined toward software aspect of CE but now i am planning to change that. so i decided to buy some devices in order to practice electronics. currently i am about to buy function generator. where i live i can buy either dual-channel 10 MHz (Siglent SDG1010) OR single-channel 30 MHz (Siglent SDG830) and both have the same price. put in mind that i will NEVER work in audio neither radio applications. my goal of electronics is Micro-controller, digital design and FPGA applications. so what do you think is more appropriate for my situation more channel or more frequency? and No i cannot have both features it will be very expensive

author: Terry01
author_rank: Frequent Contributor
timestamp: January 02, 2018, 04:55:47 pm
content: Post a link to each of the FG's you are looking at so the guys who know better can see some specs. Then they can tell you which will be best. I am still very new so can't help.Hope you get the help selecting the best unit to suit your needs.

author: taydin
author_rank: Frequent Contributor
timestamp: January 02, 2018, 05:10:14 pm
content: For digital application it will be very valuable to have more than one channel. Imagine needing to generate an I2C test signal. You will need the clock and the data. Or imagine needing to create a chip select or enable signal and then following it up with a stream of data on another pin.

author: IonizedGears
author_rank: Regular Contributor
timestamp: January 02, 2018, 05:14:12 pm
content: I don't think he should get a signal generator for test data, the buspirate is a much better buy for that.However, a signal generator would be good for producing a clock signal.Sent from my Pixel XL using Tapatalk

author: Zx Spectrum
author_rank: Contributor
timestamp: January 02, 2018, 05:14:58 pm
content: i think you are right. this means i am left with Siglent SDG 1010 which has only (10 MHz) frequency.do you think that is enough

author: taydin
author_rank: Frequent Contributor
timestamp: January 02, 2018, 05:28:25 pm
content: I think it will be sufficient for most learning applications. And many times, a digital circuit can be operated at a lower clock speed without any issues. Let's say you are working with an SPI EEPROM. The device might be rated up to 50 MHz, but it will work at 10 MHz as well, just slower.

author: taydin
author_rank: Frequent Contributor
timestamp: January 02, 2018, 05:44:57 pm
content: Quote from: IonizedGears on January 02, 2018, 05:14:12 pmThis is a great tool to have as well. I knew about the bus pirate as a simple logic analyzer, but didn't know that it could also generate digital signal patterns.

author: IonizedGears
author_rank: Regular Contributor
timestamp: January 02, 2018, 06:17:05 pm
content: Quote from: taydin on January 02, 2018, 05:44:57 pmYeah! The buspirate lets you communicate with a bunch of different protocols (I2C, SPI, 1-wire, etc.) up to I think 400kHz and it was an indispensable tool when I was trying to configure and troubleshoot some no-name Chinese ADCs I got.It's a surprisingly versatile tool:http://dangerousprototypes.com/docs/Bus_Pirate

author: Terry01
author_rank: Frequent Contributor
timestamp: January 02, 2018, 06:47:17 pm
content: Quote from: Terry01 on January 02, 2018, 04:55:47 pmSorry, just noticed my DOH!!Ejit!I see you gave all the info needed in your 1st post. My head is full of flu and swimming with flu pills! Maybe more swimming than I 1st thought!

author: exe
author_rank: Unknown
timestamp: January 02, 2018, 07:10:17 pm
content: I'm not sure how a signal generator would help with digital circuits. Anyway, I'd go for something like analog discovery: scope, AWG, logic analyzer and pattern generator in one device. It doesn't go too high in frequency, specs are not impressing, but I like it (although yet to test its digital functions).

author: tautech
author_rank: Super Contributor
timestamp: January 02, 2018, 07:11:22 pm
content: Quote from: Zx Spectrum on January 02, 2018, 05:14:58 pmIt should be.I've got a 1010 that I've had for years and if I was to replace it I'd get one of the newer X series.All the X models have the same specs for both outputs, something the earlier 1000 series doesn't.The 2042X while probably more than you want to spend is higher signal fidelity product but a cheaper and nearly as capable unit is SDG1032X.This is the link for all Siglent AWG's:http://www.siglent.com/ENs/pd.aspx?tid=16&T=1

author: Zx Spectrum
author_rank: Contributor
timestamp: January 02, 2018, 07:54:44 pm
content: Quote from: tautech on January 02, 2018, 07:11:22 pmi got the feeling that you think that dual channel is more appropriate than a single channel function generator.could you clarify why dual channel is betterthanks

author: tautech
author_rank: Super Contributor
timestamp: January 02, 2018, 08:13:36 pm
content: Quote from: Zx Spectrum on January 02, 2018, 07:54:44 pmFor one, you can use the second or first as a low power DC supply which for breadboard use might be all you need.I have on occasion used a second channel in logic design checks when you need inputs in different states and different levels. There's a # of features in the Siglent's were you can tie/link outputs in configurations that help.Sure, with a few 4000 logic IC's you can achieve the same result be it's easier to have it built into the AWG.I hankered for a function gen for years and the first I had was a Philips 2 MHz single channel job that now would be the last thing I'd use. You will start out thinking one channel is enough and for a while it is, but as knowledge and needs develop it won't be long until you want/need more.A SDG1032X is a good choice and has plenty of capability to grow into.SDG2042X is better signal quality as mentioned and some have found ways to improve them to SDG2122X and you can read about that in the SDG2042X thread.I've heard SDG1032X can beimprovedto SDG1062X in a similar way.

author: rstofer
author_rank: Super Contributor
timestamp: January 02, 2018, 09:04:34 pm
content: Quote from: Zx Spectrum on January 02, 2018, 07:54:44 pmI bought the Siglent SDG 2082X so I could duplicate the Valentine Day heart here:https://www.eevblog.com/forum/chat/a-valentine's-day-activity-for-your-scope-and-function-generator/msg1136847/#msg1136847Read the specs carefully! It puts out 80 MHz sine wave but only 25 MHz square wave.https://www.batronix.com/pdf/Siglent/SDG2000X/SDG2000X-Datasheet.pdfNotice that the project requires an X and Y signal output to the scope. Thus 2 channels. Notice also the ability of each channel to stack in harmonics at phase shifts relative to the dialed in fundamental. I think the 2082 will go up to 8 harmonics. In other words, it will build some very sophisticated signals. Plus it has a lot of built-in signals, RTFM.But all of that stuff is analog and you're interested in digital. So, build the digital signals with an Arduino or an FPGA (depending on speed). It's pretty easy to create a 100 MHz chain of logic signals with an FPGA. Similarly, it's easy to implement SPI or I2C with an Arduino and only slightly more difficult with an FPGA (actually, SPI is easy, it's I2C that's a PITA).Probably the best tool for digital work is the new Digilent Digital Discoveryhttp://store.digilentinc.com/digital-discovery-portable-logic-analyzer-and-digital-pattern-generator/This thing will Do Everything But Eat (DEBE device) and it's fast! In a more analog environment, the Analog Discovery 2 is magnificent.I have only had crappy signal generators for decades. My interest is digital and I can generate just about anything I need. It is absolutely true that I bought the 2082 for the Heart project but it is pretty nice to have a real signal generator when testing analog kinds of circuits. Transistor amplifiers, op amp circuits, filters, etc. Of course, the Analog Discovery 2 does a better job within it's range but adding harmonics isn't one of its capabilities. It will produce a Bode' plot of a filter with no external gadgetry. Download the Waveforms software and run some of the demos, see what you think.I really like my SDG2082X!

author: xani
author_rank: Frequent Contributor
timestamp: January 03, 2018, 06:09:51 am
content: Quote from: Zx Spectrum on January 02, 2018, 04:31:00 pmThe more important question is "what gear you actually have and what would adding a signal generator to it allow you to do?". Do you have scope ? Logic analyzer ?.If you don't know what you'd even use it for I'd recommend just getting one of those $50-$100 chinese DDS-based generators, they look like toys but actually are not bad at their job and it might be enough for what you doOther option I'd suggest looking into is something like Analog Discovery 2http://store.digilentinc.com/analog-discovery-2-100msps-usb-oscilloscope-logic-analyzer-and-variable-power-supply/(it has education discount too). It is basically a bunch of entry level test equipment crammed into tiny package, that's also scriptable so you can do neat things like generate digital pattern, feed it to your circuit and look what it is outputting, or vice versa.You can do a ton of stuff with that little box and even stuff that normally would require pretty pricy gear, like network analyzer (altho only to about ~10MHz range)

author: Zx Spectrum
author_rank: Contributor
timestamp: January 03, 2018, 12:27:34 pm
content: Ok i got it the analog discovery is more suitable.But still in case the only devices available to get are:Siglent SDG 1010Siglent SDG 830Siglent SDG 805Which one is suffecient for my needs.

author: pigrew
author_rank: Frequent Contributor
timestamp: January 03, 2018, 04:40:46 pm
content: I'd lean towards the extra features of the SDG1010, assuming that it's high enough frequency for your needs.It has an extra channel, 10 MHz ref in, a basic frequency counter, and a modulation input. These things can come in very handy. It looks like most of the specifications are identical between these models.I wouldn't use it to generate digital signals. Also note that with very low frequencies (1 Hz or lower), the output frequency becomes inaccurate (at least on the SDG2042X).Use another micro or a bus pirate or whatnot to generate digital test signals.

author: bson
author_rank: Unknown
timestamp: January 04, 2018, 10:13:18 pm
content: Quote from: exe on January 02, 2018, 07:10:17 pmTo see how your circuit responds to say a group delayed clock, like one distributed over a cable? Or one with -30dB of the commercial FM band on top of it? Or signals through an isolator or pulse magnetics?Digital is only digital when it works correctly; when not it becomes analog.

author: Zx Spectrum
author_rank: Contributor
timestamp: January 04, 2018, 11:28:21 pm
content: So at the end of the day which one of this EXECLUSIVE group should i buy???Siglent SDG 1010Siglent SDG 830Siglent SDG 805Please don't say ( depending on what you want) i have explained what i want in the question description and mind you i dont need extra features i just need suffecient one ( for ecenomic reasons) as long as i won't have to by an upgrade very soonSo a minimalist but yet suffecient choice (for the next 5 years) is better than an overkill choice

author: tautech
author_rank: Super Contributor
timestamp: January 04, 2018, 11:43:47 pm
content: Quote from: Zx Spectrum on January 04, 2018, 11:28:21 pmThese are all entry level AWG's and any of them will meet your humble requirements.If you'll only ever need one channel you won't likely ever need more than 30 MHz.But so often choice to a firm budget in years to come was the wrong choice therefore get the 805 and live with the knowledge that you may need to upgrade at some time in the future but not so much for BW but for additional features.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 04, 2018, 11:53:26 pm
content: Quote from: Zx Spectrum on January 02, 2018, 04:31:00 pmNeither will help much. Not for that kind of projects.How exactly do you want to use a signal generator for digital projects?Give 3-5 examples of signals that you think you will need, and what for.

author: Zx Spectrum
author_rank: Contributor
timestamp: January 05, 2018, 03:47:08 am
content: Currently i just want to use it to learn basic AC circuit analysis from this book:Introductory Circuit Analysis by Robert BoylestadAnd later on to learn basic electronic circuits from atext book like:Electronic Principles by Albert Paul MalvinoAnd i don't know which of the previously mentioned AWGs is suffecient to cover the material and experiments in these books

author: tautech
author_rank: Super Contributor
timestamp: January 05, 2018, 07:25:22 am
content: Quote from: Zx Spectrum on January 05, 2018, 03:47:08 amThere's nothing very challenging in Malvino for a 5 MHz AWG..........just checked.I think I have Boylestad too, I'll have to find where I put it.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 05, 2018, 01:11:24 pm
content: Since you don't need a specific range of frequency, then any soundcard from a PC/laptop/phone is more than enough to understand and learn AC circuits.A soundcard can be used as a dual channel generator + oscilloscope. There are many free programs that can generate any waveform and act as an oscilloscope at the same time. I like this one:https://www.zeitnitz.eu/scope_en

author: rstofer
author_rank: Super Contributor
timestamp: January 05, 2018, 03:22:26 pm
content: Quote from: Zx Spectrum on January 05, 2018, 03:47:08 amThat's an entirely different application than you stated in your OP. Now you want to work with AC circuits and a signal generator will be very important. For digital circuits, a signal generator isn't nearly as important.I would go for dual channels. It may come to pass where you want to model one of the circuits from the analysis portion of the book where they use 2 signal sources. Or maybe you want to work on some kind of modulator requiring a carrier and a modulation signal.A scope will be much more useful than a signal generator so make sure you have that covered first. In the audio spectrum, there are a lot of DIY signal generators and even the cheap Chinese SGs will work although they will tend toward single channel.Here is one example and there are many more:http://www.ebay.com/bhp/function-generator-kit

author: Zx Spectrum
author_rank: Contributor
timestamp: January 05, 2018, 03:58:03 pm
content: Quote from: tautech on January 05, 2018, 07:25:22 amThank you for your answer. So i understand from you that no need for dual channel for the material in both books

author: RoGeorge
author_rank: Super Contributor
timestamp: January 05, 2018, 04:55:58 pm
content: Since you look eager to buy something (I know that buying fever too), then pick the dual channel. Heaving 2 channels available will help with a lot of experiments you may want to try, even if the experiments are not from those books. 3MHz or 5 or 30 MHz, that number doesn't really matter for you, because you will not do RF in that range anyway, and after all, they are almost the same frequency: under 100 MHz.One more thing. I was looking briefly over the two books.If you want to start from electricity basics and AC circuits just because you want to finally work with microcontrollers and FPGAs, then I don't think this is the right path.Those books are NOT for learning MCUs and FPGAs, in fact they are almost unrelated with digital circuits. Those are books for analog electronics, not digital.

author: Zx Spectrum
author_rank: Contributor
timestamp: January 05, 2018, 05:32:56 pm
content: Thank you for your answer.Of course i know that these books don't cove my microcontrollers , fpga or digital design ( i am not that newbie)Actually i am very good at ARM7TDMI assembly and VHDL i love digital design and i am good at it.But you see the thing is that i recently i asked the following question:https://electronics.stackexchange.com/questions/347387/do-i-need-to-learn-ac-circuits-for-working-with-micro-controller-projectsAnd everybody assured me that i need a lot of AC skills (honestly i am not very convenced) but it seems like i gotta do what i gotta do so i grabed my old, circuit analysis book and now i am getting ready for some very boring study in the next 10-18 months

author: RoGeorge
author_rank: Super Contributor
timestamp: January 05, 2018, 09:25:02 pm
content: I see. TBH, I've never been a big fan of electronics stack exchange.Indeed, you will need some AC understanding as soon as you want to transmit an edge (in fact, any other form of a variable signal) over a wire.- I am thinking here mostly about understandingtransmission linesandreflections.Any wire is also a transmission line. When the signal arrive to the end of the transmission line, it will reflect back and forth many times between the two ends of the transmission line. Depending on the impedance matching and the length of the wires, this can be so bad that the digital circuit at the other end of the wire will not be able to distinguish between 0 and 1. Another problem can be when multiple signals are routed together (with multiple transmission lines) for a longer distance, like in a data bus for example. If the transmission lines are not the same, different data bits will arrive at different moment. Some of them might arrive too late and miss the sampling edge of the receiving data bus.- Another 'must know about' isFourier, especially the equivalence between time domain and frequency domain. For an EE, this is nothing new, I don't know if a CE is familiarized with that. Roughly saying, any waveform signal can be decomposed to (or reconstructed from) a sum of constant sinusoidal signals (each with its own constant amplitude, frequency and phase). As soon as you want to do DSP, then expect lots and lots of Fourier topics and heavy math.If you think you know enough AC to continue with the above 2 topics, then the books can be entirely skipped. Otherwise, go ahead with those books, but not too deep. They look to me more like reference books. Way too broad for what you need, they cover almost anything an EE will ever need.For transmission lines, I found these EE lectures ofGreg Durginas very good:For AC circuits and learning experiments I will go for adual channelsignal generator rather than a higher frequency. Dual channel will allow experiments about phase shift and signal mixing, experiments that can't be done with only one channel. From my personal experience, a sound card can be enough for the purpose.Why I keep mentioning the sound card? TBH, I have a Rigol DG4102 signal generator (dual channel/100MHz/DDS), but I didn't use it at all for MCUs or FPGAs design/debug.

author: Zx Spectrum
author_rank: Contributor
timestamp: January 05, 2018, 10:16:44 pm
content: Thank you for the detailed answerDon't you think that i will need more than 10 MHzAWG once i wil start studying about high speed digital designI know that when i will study high speed digital design i will need high freq pattern generator not AWG, but i dont know whether for that later study i will have to simulate high freq sine waves as that what will happend with square signal under high freq conditionsAnd thus i would need more than 10 MHz AWG.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 05, 2018, 11:18:06 pm
content: Quote from: Zx Spectrum on January 05, 2018, 10:16:44 pmNot at all. 1 or 10 or 100 MHz are almost the same. They are all good enough for learning and understanding AC circuits basics. Once you did that, you can simply discard the signal generator, because it won't serve you much for digital design even if it was 1 GHz.After all, for digital design, the clock frequency doesn't matter. What it really matters is howfastare the edges. You can have exactly the same problems with a square 100 KHz as with a square 100 MHz. It's all about edges. As a gross over simplification, you can think about digital signals as being nothing more than just edges followed by long periods of constant DC, so edges rise time is critical, how far apart are two edges (that gives the frequency) is not so critical.Now, if you look at the rise time specifications for a 10 or 100 MHz generator in order to compare the two, you will see that the rise time (how fast are the edges) are basically the same, while the maximum frequency is 10 times bigger.By high speed digital design I understand GHz range clocks and Gbps transfer speeds. No signal generator in that price range will be of any help in high speed digital. If you think about debugging for high speed, you will most probably use another SERDES from a FPGA anyway.

author: Zx Spectrum
author_rank: Contributor
timestamp: January 05, 2018, 11:23:05 pm
content: Ok thank youSo i will go for the Siglent SDG 1010You have benn a lot of help

author: Electro Fan
author_rank: Super Contributor
timestamp: January 06, 2018, 12:21:24 am
content: The SDG1010 sells for about $329. It has a max output frequency of 10 MHz. It samples up to 125 MSa/s. It includes 46 built-in arbitrary waveforms. It has a 3.5" display.The SDG1032X sells for about $359. It has a max output frequency of 30 MHz. It samples up to 150 MSa/s. It also offers Siglent's EasyPulse. It includes 196 built-in arbitrary waveforms. It has a 4.3" display.(These are the prices at Siglent America; they might offer a discount for EEVblog members, or perhaps there are better prices somewhere else. The prices might be different in your area.)There are probably some other differences you can find in the data sheets and manuals:http://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDG1000_DataSheet_DS02010-E08A.pdfhttp://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDG1000_UserManual_UM02010-E08B.pdfhttp://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDG1000X_DataSheet_DS0201X_E01E.pdfhttp://www.siglentamerica.com/wp-content/uploads/dlm_uploads/2017/10/SDG1000X_UserManual_UM0201X-E01D.pdfFor about $30 more you might want to consider the SDG1032X.

author: tautech
author_rank: Super Contributor
timestamp: January 06, 2018, 01:24:32 am
content: Quote from: Electro Fan on January 06, 2018, 12:21:24 amMore than might !I have it on good authority they can beimprovedto the 60 MHz version, SDG1062X.But of course take no notice of me, I'm just a seller and sellers are always trying to up-sell, right.IF the OP takes this road he can be fairly confident that he'll never need anything better for maybe his life.

author: RoGeorge
author_rank: Super Contributor
timestamp: January 06, 2018, 01:58:57 am
content: Quote from: Electro Fan on January 06, 2018, 12:21:24 amIndeed, SDG1032X looks like a much better choice.