Other Parts Discussed in Thread: VCA824
Hi,
I would like to ask you to give me your advice about THS3491-VCA824 circuit.
The problem is the gain difference between design value and measured value.
I designed the THS3491 gain as around x4.91 but measured gaind is around x4.5.
(THS3491 gain = 1 + 560/143 = 4.91)
That is to say, input is 0.22Vpp and output is around 0.99Vpp.
And I tried to set register 1K ohm between THS3491 and VCA824.
As a result, THS3491 output became 0.96Vpp and after 1K ohm the voltage became 0.65Vpp.
I do not understand why THS3491 behaves as this.
As I attached my schematics and block diagram, will you check it please?
Thank you very much for your support.
Best Regards,
Takumi