# XR2206 fuction generator amplitude adjustment (2)

#### Ben Reji

Joined Mar 9, 2023
9
Hello Guys, so is there any other way through which we could actually change the amplitude for square wave. Thanks

Moderator edit: new thread created from this and this.

Joined Jan 15, 2015
7,192
Sure. What amplitude would you like a square wave to be? What do you have now and what would you like to have? Also what is your source now?

Ron

#### Dodgydave

Joined Jun 22, 2012
10,826
Are you talking about the XR2206 chip, if so it has an open collector output for the square wave.

#### Ben Reji

Joined Mar 9, 2023
9
Sure. What amplitude would you like a square wave to be? What do you have now and what would you like to have? Also what is your source now?

Ron
Right now its 9.60V, I'm seeing if its possible to go from 0V- 9.0V
Also, the amplitude for my sine/Triangle wave is clipping at the top after 2V, so im not able to go till 3.0V which is what i needed. Im using 9V for the circuit. The following is my circuit.

#### Ben Reji

Joined Mar 9, 2023
9
Are you talking about the XR2206 chip, if so it has an open collector output for the square wave.
Yes, can you tell me in more detail

#### Dodgydave

Joined Jun 22, 2012
10,826
Yes, can you tell me in more detail
The Square wave output is on pin 11 , it has an open collector output, which means you have to provide a pull up resistor to the positive supply the to create a full square wave, read the datasheet.

#### Ben Reji

Joined Mar 9, 2023
9
The Square wave output is on pin 11 , it has an open collector output, which means you have to provide a pull up resistor to the positive supply the to create a full square wave, read the datasheet.
do you know of the clipping issue for triangle wave, after 2V, the wave is clipping, so its not going above 2.4V.

#### LowQCab

Joined Nov 6, 2012
3,059
The External Controls must be duplicated as in the Spec-Sheet ..........
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#### Ben Reji

Joined Mar 9, 2023
9
The External Controls must be duplicated as in the Spec-Sheet ..........
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View attachment 290241
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Thanks, i will try that, also I am using a 10uF cap for the frequency range of 1-10Hz, but im getting till 19Hz, any idea how to fix this issue?
Like for all the Frequency range, im getting either higher or lower than what i have stated.
Thanks,,,

#### Dodgydave

Joined Jun 22, 2012
10,826
Thanks, i will try that, also I am using a 10uF cap for the frequency range of 1-10Hz, but im getting till 19Hz, any idea how to fix this issue?
Like for all the Frequency range, im getting either higher or lower than what i have stated.
Thanks,,,
You adjust the frequency with the Variable resistor on pin 7 to ground, have you got the right values?

Post pictures of your circuit board.

#### sarahMCML

Joined May 11, 2019
242
You will also get a better output voltage swing if you run the circuit from 12 volts rather than 9 volts, so remove the 7809 regulator. If you have a REAL XR2206, rather than a fake one, they will take any supply voltage from 10 volts up to 26 volts. They start to get poor below 10 volts, depending on the individual I.C, at least, my 6 real ones do!

#### Ben Reji

Joined Mar 9, 2023
9
Thanks, i will try that, also I am using a 10uF cap for the frequency range of 1-10Hz, but im getting till 19Hz, any idea how to fix this issue?
Like for all the Frequency range, im getting either higher or lower than what i have stated.
Thanks,,,
You will also get a better output voltage swing if you run the circuit from 12 volts rather than 9 volts, so remove the 7809 regulator. If you have a REAL XR2206, rather than a fake one, they will take any supply voltage from 10 volts up to 26 volts. They start to get poor below 10 volts, depending on the individual I.C, at least, my 6 real ones do!
Awesome, thanks man, im getting above 3V now, so should i use any other regulator which will provide 12V?. Also do you have any idea on the frequency range cap. For 1-10Hz im getting 1-19Hz and others are also bit off. Thanks

#### sarahMCML

Joined May 11, 2019
242
Awesome, thanks man, im getting above 3V now, so should i use any other regulator which will provide 12V?. Also do you have any idea on the frequency range cap. For 1-10Hz im getting 1-19Hz and others are also bit off. Thanks
Your diagram showed you using a 12V supply into the 7809 regulator. Is this not stable enough for you to use as it is? If not , you can use any of the 7812 variants (LM7812, uA7812, L7812 etc) in place of the 7809, but you will need to supply it with at least 15V DC for it to regulate properly.

Electrolytic capacitors have a rather large tolerance for their values, so C5 could be lower than 10uF, allowing the frequency to go higher. Best to use a polyester or other plastic type there.
You can also change R6 if all the frequencies are going higher than you wish.

#### LowQCab

Joined Nov 6, 2012
3,059
Don't bother with a Voltage-Regulator,
just improve the Filtering of the 12-Volt Supply with a large Bulk-Storage-Capacitor, ( ~1000uF or more ).
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#### Ben Reji

Joined Mar 9, 2023
9
Your diagram showed you using a 12V supply into the 7809 regulator. Is this not stable enough for you to use as it is? If not , you can use any of the 7812 variants (LM7812, uA7812, L7812 etc) in place of the 7809, but you will need to supply it with at least 15V DC for it to regulate properly.

Electrolytic capacitors have a rather large tolerance for their values, so C5 could be lower than 10uF, allowing the frequency to go higher. Best to use a polyester or other plastic type there.
You can also change R6 if all the frequencies are going higher than you wish.
So if i give 12V input, the square wave will get the same output right, is there any way to reduce that get below 10V output for the same.

#### Ben Reji

Joined Mar 9, 2023
9
Your diagram showed you using a 12V supply into the 7809 regulator. Is this not stable enough for you to use as it is? If not , you can use any of the 7812 variants (LM7812, uA7812, L7812 etc) in place of the 7809, but you will need to supply it with at least 15V DC for it to regulate properly.

Electrolytic capacitors have a rather large tolerance for their values, so C5 could be lower than 10uF, allowing the frequency to go higher. Best to use a polyester or other plastic type there.
You can also change R6 if all the frequencies are going higher than you wish.
So if i give 12V input, the square wave will get the same output right, is there any way to reduce that get below 10V output for the same.

#### Dodgydave

Joined Jun 22, 2012
10,826
Yes as said before, the square wave output is an open collector output, so if you use a 1K pull up resistor and a Zener diode across the output say 9V , then it will be limited to that voltage.

#### Ben Reji

Joined Mar 9, 2023
9
Yes as said before, the square wave output is an open collector output, so if you use a 1K pull up resistor and a Zener diode across the output say 9V , then it will be limited to that voltage.
Thanks, I will try this