# Triangle wave (170Hz) generator's circuit requirement

#### Nomi 1114

Joined Dec 4, 2017
103
Dear All,

Hope you all are fine. Here i would like to ask onequestion, from last 4 days i am working and thinking for triangle wave generator (holding output frequency of 170 or 180 Hz) by using the crystal oscillator (Frequency = 32.768 Khz). But i am unable to draw and also didn't find such circuit. By using 74HC40103 and 74HC74 i tried to draw and get some suitable results as per requirement, but failed (for simulation purpose i am using LTspice software). If someone can help me in this regard then i shall be highly grateful to you in this act of kindness.

Anxiously waiting for your kind and positive response.

Regards
nomi

#### ci139

Joined Jul 11, 2016
1,538

#### Marley

Joined Apr 4, 2016
353
Generating an accurate triangle wave from a crystal oscillator usually requires the triangle slope to be created from a series of steps. These steps are then smoothed out using a filter.
A triangle is analog - because it is a slowly changing linear voltage. A crystal oscillator output is digital square wave.
So normally a logical circuit drives an analog-to-digital converter (DAC) to produce the triangle wave.
The DAC can be as simple of a chain of resistors.
Depending on the DAC, the crystal oscillator is normally 2^8 or 2^16 or some other multiple of the triangle frequency.

#### atferrari

Joined Jan 6, 2004
4,003
You could do it (I did) with a dual opamp: square signal integrated to get the triangles.

Many results handy if you search.

#### Nomi 1114

Joined Dec 4, 2017
103
Dear all,

Thank you very much for your help and kind cooperation. Actually i am new in this area as well new for using LTspice software. I am unable to generate frequency of 32.768 KHz ... i used crystal oscillator can generate the frequency of 24 MHz .. so how can i generate exactly the desired frequency ? For your reference circuit sis attached, Please suggest me which parameter is required to change to get desired freq ???

#### atferrari

Joined Jan 6, 2004
4,003
Dear all,

Thank you very much for your help and kind cooperation. Actually i am new in this area as well new for using LTspice software. I am unable to generate frequency of 32.768 KHz ... i used crystal oscillator can generate the frequency of 24 MHz .. so how can i generate exactly the desired frequency ? For your reference circuit sis attached, Please suggest me which parameter is required to change to get desired freq ???

View attachment 199128
Come on!
That program is good for you to try things with no risk of damaging anything.
Do not be lazy. Do some efforts first.

#### Alec_t

Joined Sep 17, 2013
11,388
I've never been able to get that LTspice oscillator working properly. Whatever values I choose for the xtal properties (series inductance, parallel capacitance) the resulting frequency is always about 4MHz. Member @Bordodynov may have a solution? In the meantime you could just use a voltage source to provide the 32768Hz signal.

#### peterdeco

Joined Oct 8, 2019
183
Do a google for "triangle wave schematic". A bunch of diagrams come up, some as simple as a 555 timer to produce triangle waves.

#### Nomi 1114

Joined Dec 4, 2017
103
I've never been able to get that LTspice oscillator working properly. Whatever values I choose for the xtal properties (series inductance, parallel capacitance) the resulting frequency is always about 4MHz. Member @Bordodynov may have a solution? In the meantime you could just use a voltage source to provide the 32768Hz signal.
Dear Alec_t,

Thanks for your reply. i spend almost whole day to get such desired result, honestly speaking i am not a lazy guy, i worked hard but unfortunately to get desired value of frequency. so please suggest me further !!!

Thanks

#### Nomi 1114

Joined Dec 4, 2017
103
Do a google for "triangle wave schematic". A bunch of diagrams come up, some as simple as a 555 timer to produce triangle waves.
Dear peterdeco,

Thanks for your kind reply, i just wanna ask that i had tried to find such a circuit, but fail to get it. by using Xtal oscillator of 32.768KHz i wanna produce a triangle wave form of 170/180 hz, if you have please refer me. I shall be highly grateful to you for this act of kindness....

Thanks

#### Nomi 1114

Joined Dec 4, 2017
103
Come on!
That program is good for you to try things with no risk of damaging anything.
Do not be lazy. Do some efforts first.
Dear atferrari,

Thanks for your reply. i spend almost whole day to get such desired result, honestly speaking i am not a lazy guy, i worked hard but unfortunately to get desired value of frequency ( by changing series inductance, parallel capacitance, resistance, etc but some time i found 11Khz and mostly time 23 MHz, other no values, i am stuck here !!!) . so please suggest me further !!!

I shall be highly grateful to you for this act of kindness...

Thanks

#### Bordodynov

Joined May 20, 2015
2,623
For oscillators on the inverter, inverters with suffix "U", i.e. non-buffered inverters, must be used. It is also necessary to improve the accuracy of the quartz oscillator calculation for reliable calculation, which I did (reltol=10u).

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#### atferrari

Joined Jan 6, 2004
4,003
For oscillators on the inverter, inverters with suffix "U", i.e. non-buffered inverters, must be used. It is also necessary to improve the accuracy of the quartz oscillator calculation for reliable calculation, which I did (reltol=10u).View attachment 199137View attachment 199138
Aren't unbuffered versions of most of CMOS ICs a thing of the past?

#### Bordodynov

Joined May 20, 2015
2,623
See

#### atferrari

Joined Jan 6, 2004
4,003
I've checked two catalogs and effectively there are few different ICs unbuffered.

#### Nomi 1114

Joined Dec 4, 2017
103
Dear All,

Thank you very much for your positive response and kind help. Everyone give me suggestions and some good ideas, i am working on it and hope fully achieve good results soon. Maybe later i will ask something related to Integrator circuit by using LF353 op-Amp IC.

Once again Thank you very much for your kind cooperation.

Regards
Nomi

#### Nomi 1114

Joined Dec 4, 2017
103
Dear all,

Once again i am here asking for one question related to subject topic, as i asked previously asked previously that i am interested to design a 170 Hz triangle waveform generator by using 32.768Khz crystal oscillator, by your instructions and kind help i am success fully generated 170 Hz wave form but the shape of wave form is not pure triangular, Please find the attached cct and suggest me how can i get pure triangular wave with amplitude 0 ~ 4.5V/5V, what values and topology for RC network is good to achieve desired results. At f2 frequecny is 170 Hz and manitude is 0 ~5V but at output of LF353 (opamp) magnitude is bit lower. already spend too much time but didn't find the solution. please suggest me with your kind recommendations.
Thanks

#### atferrari

Joined Jan 6, 2004
4,003
Dear all,

Once again i am here asking for one question related to subject topic, as i asked previously asked previously that i am interested to design a 170 Hz triangle waveform generator by using 32.768Khz crystal oscillator, by your instructions and kind help i am success fully generated 170 Hz wave form but the shape of wave form is not pure triangular, Please find the attached cct and suggest me how can i get pure triangular wave with amplitude 0 ~ 4.5V/5V, what values and topology for RC network is good to achieve desired results. At f2 frequecny is 170 Hz and manitude is 0 ~5V but at output of LF353 (opamp) magnitude is bit lower. already spend too much time but didn't find the solution. please suggest me with your kind recommendations.
Thanks

View attachment 199866
Dare to suggest you read what I posted here . It is running on my bench right now.

Do calculate or tweak the values to get your desired frequency yourself.

#### Nomi 1114

Joined Dec 4, 2017
103
Dear Respected atferrari,

Thank you very much for your kind reply. I had reviewed and designed the circuits in LTspice tool, referred by you in above mention post. in that ckt you used TL072, but i replace this IC with LF353, coz it's replacement each other. but unfortunately didn't found good results what i need. I think the values of RC not suitable selected by me. if you help me in this regards then i shall be highly grateful to you for this act of kindness. (If you need Schematic of the ckt i can provide you)

Regards
Nomi