Hi Everybody
this is my first thread on this forum. Im looking for some suggestion for understanding why my simulation is going wrong.
Im designing my own synthetizer , and Im using LM13700 by Texas Instrument for designing all the different block.
Im using a Spice Model (downloaded from TI's website) to simulate everything before solding, and the first simulation of a VCA (voltage controlled amplifier) was perfect. For this first simulation I used the schematic from the application note of Datasheet (so im quite sure it'll work). I did the same for the second simulation of a VCO (voltage controlled oscillator triango/square) but in this case anything look like working. I've double checked the second schematic (from http://www.ti.com/lit/ds/symlink/lm13700.pdf datasheet) , what should I do?
Can anyone help me to find the problem?
Here there are the two simulation: the first is perfectly working ( triangular control of the amplification)
in the second case the output remain all the time constant.
why the first is working and the second one don't?
![upload_2015-3-11_0-8-42.png upload_2015-3-11_0-8-42.png](https://makerv2.webteractive.co/forums/data/attachments/17/17483-bd64662a3c1dcfb64c13f5ea4a167fdf.jpg)
this is my first thread on this forum. Im looking for some suggestion for understanding why my simulation is going wrong.
Im designing my own synthetizer , and Im using LM13700 by Texas Instrument for designing all the different block.
Im using a Spice Model (downloaded from TI's website) to simulate everything before solding, and the first simulation of a VCA (voltage controlled amplifier) was perfect. For this first simulation I used the schematic from the application note of Datasheet (so im quite sure it'll work). I did the same for the second simulation of a VCO (voltage controlled oscillator triango/square) but in this case anything look like working. I've double checked the second schematic (from http://www.ti.com/lit/ds/symlink/lm13700.pdf datasheet) , what should I do?
Can anyone help me to find the problem?
Here there are the two simulation: the first is perfectly working ( triangular control of the amplification)
in the second case the output remain all the time constant.
why the first is working and the second one don't?
![upload_2015-3-11_0-8-42.png upload_2015-3-11_0-8-42.png](https://makerv2.webteractive.co/forums/data/attachments/17/17483-bd64662a3c1dcfb64c13f5ea4a167fdf.jpg)