TS472

[DSchi.1]

Hi!

I'm want to use the component TS472. When I use an input signal -30dBu and a gain 40db it's work fine. When I use an input signal

with 0dBu and a gain 0dB it doesn't word. I don't know why. The outputsignal is less then 1Vpp and not the wave from the input.

According data sheet the inputsignal could be +-0,3V from Vss.

What can I do that this issue is working fine?

[Jiri HLADIK]

Hello,

Do you use eval board or your own PCB? Possibly can you share the schematic and how do you set the gain? (by resistor?). It would be also helpful to get oscilloscope traces when working correctly and when failing.

[DSchi.1]

Hi Jiri,

I use the eval board. I shwitch the jumper to 0dB and on the input is a signal 1kHz with 2Vpp.

On the output is a signal less than 1Vpp.

When i reduce the input Signal to less 1Vpp then on the output i have a signal more than 2Vpp (Gain 6dB Jumper).

Is there a limit for the input voltage?

I want to use the TS472 for a microphon signal -30dBu and an aux signal +3dBu. Micrphon works fine but aux doen't work.

Kind regards

Dieter

[Jiri HLADIK]

Dear Dieter,

can you specify which evaluation board do you use? Is it  STEVAL-CCA023V1?

Regarding to input voltage range. The maximum range is 70mVrms (see table 5. in datasheet) so sine signal 1Vpp is certainly above this value.

Please note that signals above 0.1Vpp causes high THD so output signal might be distorted. (this is shown in Figure 22 and following).

This device is only preamplifier so it is designed to work with signals coming from microphones which usually provide several mV range. Can I ask why do you need such high input voltage range? Does your microphone really generate signal above 100mVpp?

Best regards

Jiri