Don't buy any kit with XR2206 WFG - Page 1
Forum section: electronics / general

author: dbctronic
author_rank: Regular Contributor
timestamp: July 04, 2020, 06:25:22 pm
content: Every once in a while, you need to bang up some little analog project and don't want to get stuck programming to drive a digitally controlled thingy. Sure, digital waveform generators there are, aplenty, but...Anybody remember the venerable XR2206? Easy to use, full analog square/triangle/sine generator. Well, after they went out of production, one or more Chinese firms made knockoffs. There are still a few floating around, always with the date code 0489. You may see a little bright red board WFG kit, in particular. DON'T BUY!!!This run of chips has a sine output that is only about 20 mV, with huge switching spikes that are impossible to filter out. I found out that this was a generally known problem.I went on a tear last year looking for XR2206s, and in desperation bought a couple of such kits from several firms just to snag the chip. All had the bogus 0489 b******, and they all had the defective sine output. And the kit was perfectly useless without the 2206, of course. The kits were going for US$4 to 6, but when you add up several of these plus individual shipping and wasted time ...Time marches on...

author: Seekonk
author_rank: Super Contributor
timestamp: July 04, 2020, 09:30:04 pm
content: Like how hard is to copy a chip. I don't mind fakes as long as they work. I use a number of IR2153 self oscillating half bridge drivers. A feature I use is shorting the timing cap to turn both outputs off. This is a stated feature in the pdf. These fakes turn off the hi side driver, but turn on the low side. If just generating AC that isn't a problem. My circuit becomes non functional. Now I never know what I will get when I order.

author: dbctronic
author_rank: Regular Contributor
timestamp: July 04, 2020, 10:26:01 pm
content: Righto, Seekonk. If you stray from buying trustworthy parts, strongly consider playing it as plain vanilla as possible. A knockoff 2N3904 most likely has the standard base-collector-emitter pin order, but don't be surprised if some have a little below the minimum hFE, or burn up a little below VCE(max). These are minor fudges, but a blatant violation of specs such as you experienced is not, and more than once I've had similar designs in mind, especially trick enable/disable techniques such as yours, that would not have worked and would have required more redesign than it's worth.I suspect that trick enable/disable designs are rather often subject to rude surprises. Annoying when making a one-off (), VERY annoying when in the middle of a production run ().

author: Bud
author_rank: Super Contributor
timestamp: July 05, 2020, 12:16:57 am
content: If you need just one IC, drop me a PM. I have a NOS one that i can send.

author: ledtester
author_rank: Super Contributor
timestamp: July 05, 2020, 03:48:41 am
content: When did Exar stop production? I see a lot of photos with a "F0919" date code, eg:And some more variations:And are the ones sold by Jameco fakes?https://www.jameco.com/z/XR2206CP-EXAR-Corporation-IC-XR2206CP-Monolithic-Function-Generator_34972.html

author: Bud
author_rank: Super Contributor
timestamp: July 05, 2020, 06:05:23 am
content: Based on thisQuotemy bet is Jameco is selling chinese fakes. The Exar datasheet specifies no "optimal operation" supply voltage. On the other hand chinese fakes are known for lower max operational voltage.

author: Bud
author_rank: Super Contributor
timestamp: July 05, 2020, 06:09:15 am
content: There you go, a post from 3 years back:Quote from: Conrad Hoffman on August 23, 2017, 04:52:40 pm

author: ledtester
author_rank: Super Contributor
timestamp: July 05, 2020, 11:40:19 am
content: Here's some more info on the operating voltage story:https://youtu.be/ZCdTxRASqiQ?t=4m6sThe Elenco Analog/Digital Trainers (XK-550, XK-700) also use an XR2206 with +/- 12V supplies.

author: dbctronic
author_rank: Regular Contributor
timestamp: July 05, 2020, 12:43:36 pm
content: @Bud: Thanks much for the offer, but the one-off project got done another way, in fact without the oscillator altogether.Yes, I ordered 2206s from Jameco, Mouser, and several other suppliers, all were bad 0489s. Decided not to try my luck on eBay!!! Exar stopped production in the 80s. Surprised to hear of any knockoffs with later date codes, since nobody soldmeany, but I'd be wary of using them, based on my experience and the stories above.Another chip I wanted, but which is long gone, is the Maxim MAX038, a 30 MHz analogue of the 8038/2206 family. I actually talked to a support rep at Exar who had worked for Maxim at the time that one went out of production. The week the discontinuation announcement went out, her phone lit up with "Can't find them! Where are there any???" In less than two weeks they were totally gone except for the occasional popup on eBay or the like. I really wanted that one, and may again next year, time permitting. I have actually tried to design my own discrete knockoff, complete with UHF transistors pressed into service as a high speed bilevel Schmitt trigger, but I suspect it's going to be too much work.

author: wraper
author_rank: Unknown
timestamp: July 05, 2020, 01:10:13 pm
content: Quote from: dbctronic on July 05, 2020, 12:43:36 pmSounds like bullshit. Mind to explain how you managed to order it from Mouser when they are displayed as obsolete for a quite some time?

author: srb1954
author_rank: Super Contributor
timestamp: July 05, 2020, 01:12:32 pm
content: I designed an XR2206 into a product in 1978 and that product stayed in production for 13 yrs to 1991. At that time the factory producing this product would have never used anything from China so I guess the purchasing dept were still able to source the genuine part until 1991.

author: dbctronic
author_rank: Regular Contributor
timestamp: July 05, 2020, 05:39:50 pm
content: Perhaps memory mis-serves me on Mouser. I know I ordered three chips, and two of the stupid WFG kits from, of all places, WalMart online. Tayda was one supplier, my only unhappy purchase from them, and it's the only thing Jameco has sold me that was a dud.Somebody here may want to rein in their trollish posting manner a bit.If they were still being sourced in '91, well, yeah, you could probably still scare them up if they went out in the very late 80s, or in '90. I had been told they went out in the late 80s. Anyway, long ago.

author: kripton2035
author_rank: Super Contributor
timestamp: July 05, 2020, 05:57:20 pm
content: I bought this xr2206 kit on aliexpresshttps://www.aliexpress.com/item/32963105557.htmland the date code is F0918will try to find it in my boxes and test the sinus output voltage.Edit : it outputs a 5v sinus, that is quite distorded, but it is ok until 3v ppI measured @ 700Hz

author: vk6zgo
author_rank: Super Contributor
timestamp: July 05, 2020, 11:59:53 pm
content: Its not always just Chinese "clones" that have problems.Back in the 1990s, I had to pull apart an "in house" made TV transmitter remote controller to change the operating method of one of the emergency programme sources.Part of this device used a couple of National Semiconductor monostable ICs to provide longish delay times.Whilst playing with the unit, I dropped, & lost, one of the monostables-------------bummer!No problems, though, plenty in the store.I grabbed one, checked the operation---------suddenly, it kept timing out early, so the controller function didn't work any more.I borrowed the IC from one of the other functions, & all was well, but when I tried the function the new one was swapped to, it too, failed to work as designed.Must be a bad IC, let's just grab another!After 4, it became obvious that the new devices had a problem the originals did not have.Much research followed----no Google back then, just digging through books.It turned out that NS had been getting complaints that the mono wasn't reliable for short time intervals, so they redesigned it.The problem was, it now didn't work properly for long intervals, so they re-released the original IC under a new part number.We had made just two of these controllers, so it wasn't a major drama ---------we just bought a stock of the new part number ICs, changed the documentation to reflect this, & were good to go.Imagine if we had been a manufacturer with tens of thousands such units out "in the wild"!

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 06, 2020, 12:23:08 pm
content: But does the kit itself work with a real XR2206? Asking for a friend... who buys lots of junk on eBay....

author: dbctronic
author_rank: Regular Contributor
timestamp: July 07, 2020, 01:55:06 am
content: Alex:I didn't try it. It's based on a junk chip (hard to believe they didn't know), so I junked it all. It has a bright red circuit board, about 1-1/2" square, and a screw on lexan front panel, actually pretty attractive. But untrustworthy. Make purchasing decision accordingly, sez I. As has been pointed out here before, eBay and PayPal don't really have your back for these small dodgy purchases.See Kripton2035's post up this thread a few places, purchased on AlieExpress. That's the kit I bought, better sine output but still distorted. Somebody else further up the thread offered to sell a known good 2206, but evidence suggests your friend would best not bother installing it in this kit. Hmm.... keep looking.

author: rsjsouza
author_rank: Super Contributor
timestamp: July 07, 2020, 02:12:29 am
content: Just a warning about the XR2206... Even the original. It suffers from spikes on the sinewave and the fix is somewhat obscure.The discussion below mentions a few detailshttps://www.diyaudio.com/forums/solid-state/129493-xr2206.html

author: Alex Eisenhut
author_rank: Super Contributor
timestamp: July 07, 2020, 02:22:07 am
content: Hey thanks, I might have to update my sig again.I am waiting for two of these little function generators, the other type is based what they claim is a ICL8038.http://www.mit.edu/~6.331/icl8038data.pdfhttps://www.ebay.ca/itm/Professional-ICL8038-Function-Signal-Generator-Sine-Triangle-Kit-NEW-Wave-K7S9/174306174318?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649I mean this isn't some high accuracy thing, but it would be nice if it worked about as well as a late 1960s shoe-box like a Wavetek.Quote from: rsjsouza on July 07, 2020, 02:12:29 amIt's the PWL method of warping a triangle wave into a pseudo-sine. That tip is hard to get rid of, but the ICL8038 seems to have a more complex PWL implementation. (That pile of transistors between pin 3 and 2 in the 8038 vs the much simpler 2206 structure).I hope it'll make a decent waveform.

author: rsjsouza
author_rank: Super Contributor
timestamp: July 07, 2020, 02:37:04 am
content: Quote from: Alex Eisenhut on July 07, 2020, 02:22:07 amYes, that is quite difficult to "purify": I have a signal generator that operates in the same way (BK Precision 3030) and it works well, although the spikes show up depending on the load.

author: AdrianFu
author_rank: Contributor
timestamp: August 05, 2020, 05:01:45 am
content: I bought one of the Chinese XR2206 function generators. It currently sitting in the junque-box. Might use the pots one day. Ended up putting together an Arduino based keyboard input with digital display function generators.Works much better.......well just works unlike the Chinese versionAdrian

author: jewelie
author_rank: Regular Contributor
timestamp: December 09, 2022, 01:51:28 pm
content: Quick update on the cheap Chinese XR2206 signal generator kits.I got one recently, cheap as I could get from AliExpress, for the hell of it, knowing that they were a bit iffy.Mine does have the high frequency spike issues on the sine wave, which I'm not particularly bothered about.Curiously though, unlike all the videos and reports I've seen before, and unlike what the supplied paperwork said,it seems to be stable above 12V!?Additionally, with a little bit of modding using the example circuits from the original chip's data sheet-a 10uF cap between GND and the amplitude pot centre, pluschanging the 330R resistor to a 500R trim pot (the resistor that's in series with the jumper to change between triangle vs sine wave)then I could can get a sine wave that seems to measure less than1% THD(excepting those little spikes) and is stable and otherwiseclean down to 20mA p2p.I get the best sine wave shaping at approx 215R on that 500R trim pot, which makes me wonder if the 330R resistor used by default is a mistake and should actually have been 220R?- Julie

author: Kleinstein
author_rank: Super Contributor
timestamp: December 09, 2022, 01:59:25 pm
content: The best resistance for the sine trim can vary from chip to chip. So some may work better with 220 ohm and others may want 390.The 330 ohm may be taken from a datasheet or testing some prototypes. There is a reason they had the extra timmer in the original and not just a fixed resistance.

author: jewelie
author_rank: Regular Contributor
timestamp: December 09, 2022, 02:13:05 pm
content: Fair enough!BTW For reference the chip in mine that's stable above 12V appears to be this one marked XR2206CP HLF A8http://hlf-ic.cn/en/products/show-134.html

author: jonpaul
author_rank: Super Contributor
timestamp: January 15, 2023, 12:44:35 pm
content: in 1973, I used the very similar Intersil 8038 function generator in my Popular Electronics Super Audio Sweeper.50 years pass, I still have the hand wired prototype. still works, but needed new lytics and contact cleaning of Allen Bradley AB pots and rotary switches.Amazingly it's in cal, but Frequency at high end off 4%, needed a tweak of trim pot.Was an MITS kit, and PE cover.Found spare parts and discovered the super rare orignal ceramic and gold Intersil ICL 8038s as well as vintage Exar 2206s, (second design choices). The bipolar voltage regulator was a Raytheon 4194 in T0-66 métal can. these rare ICS are seen in the photoEnjoy,Jonthe ramblings of an old retired EE

author: Mark0x01
author_rank: Newbie
timestamp: February 10, 2023, 04:36:07 am
content: An old thread, but finally inventoring by stuff and I have 17 new old stock XR2066 dated 8327 if anyone needs one.

author: RandyKeenan
author_rank: Newbie
timestamp: October 09, 2024, 01:25:31 am
content: Bloggers. I have been reading the blog re the XR2206, and have found your entries very interesting and helpful. I have been evaluating XR2206 ICs from various sources and have found their performance unimpressive. Based on this blog, I assume that they are all bogus. Thus, I would like to obtain a few of the original XR2206 ICs made by Exar for comparison.

author: coromonadalix
author_rank: Super Contributor
timestamp: October 09, 2024, 01:48:53 am
content: unless you have some originals stashed somewhere loll witch i have, like the Max038, and xr8038there was a time you could get free samples ...

author: rsjsouza
author_rank: Super Contributor
timestamp: October 09, 2024, 10:08:59 am
content: Amazing photo, Jon Paul! A lot of history there. Thanks for sharing it.Quote from: jonpaul on January 15, 2023, 12:44:35 pm

author: RandyKeenan
author_rank: Newbie
timestamp: October 21, 2024, 03:01:28 pm
content: I would be interested in obtaining a couple of the XR2206 ICs.

author: valcher
author_rank: Contributor
timestamp: October 21, 2024, 04:06:21 pm
content: If my memory serves me right, the analogue of the XR2206 is the Soviet chip К174ГФ2 -https://radio-hobby.org/uploads/datasheets/k/k174gf2.pdf

author: wraper
author_rank: Unknown
timestamp: October 21, 2024, 08:17:48 pm
content: Quote from: valcher on October 21, 2024, 04:06:21 pmSeems to be the same. However it does not seem to be available for purchase either. Also there is XR2206CP from Shenzhen honglifahttp://hlf-ic.cn/en/products/show-134.htmlDunno if it's any good, though. Counterfeits with Exar logo might be just that with fake label (package looks exactly the same).

author: RandyKeenan
author_rank: Newbie
timestamp: January 10, 2025, 06:34:53 pm
content: I have been evaluating XR2206 ICs, both recent versions (allegedly bogus) and original versions. So far, the recent ones seem to work as well as the original.I have also purchased one of the XR2206 waveform generator kits from Amazon. I seems to work as claimed. I have heard that at voltages above 12V that there is instability/jitter. I have been running mine at about 24V and found no problem.

author: RandyKeenan
author_rank: Newbie
timestamp: April 30, 2025, 05:35:45 pm
content: I have continued working with the XR2206, and am working on a circuit that tames some of what I consider its shortcomings for my applications.As I have not been satisfied with the XR2206, however, I have designed and built a waveform generator that I prefer. It is based on generic ICs, namely three opamps (and two volt regs). It provides the usual wave-forms: square/pulse, triangle/ramp, sine. It covers 1Hz to 30kHz and provides duty cycle of <5% to >95% (and corresponding pos and neg ramps) with minimal frequency or amplitude variation.

author: Conrad Hoffman
author_rank: Super Contributor
timestamp: May 20, 2025, 09:41:16 pm
content: Last time I messed with counterfeit 2206 parts, the big problem was getting the original sweep range over the rated supply voltage. Other than that, they seemed to work well enough. Unfortunately, the sweep was the feature I needed.

author: Peter_O
author_rank: Frequent Contributor
timestamp: September 23, 2025, 03:38:03 pm
content: Bought a HYDZ251 kit with a 'HLF XR2206CP 24A8' in December 2024.It kind of worked from the start, but with all the problems mentioned in this thread.If you are on a tight budget and just need some kind of alternating output it's a cheap solution for a price of 3 Euros including some plexyglas housing and shipping.The triangle is better that the sinus of course.I did not spend the time to optimize the sinus.The product insert is attached below.