About the Vcomin of PGA2500

Hi Stone,

Welcome to E2E and thank you for your interest in our products.

Could you provide more information about your application like a schematic or your control description? It would be better to understand this issue.

Thank you.

Best regards,

Luis Fernando Rodríguez S.

Hi Luis Fernando Rodríguez S.

Thanks for your reply.  my application describe as below :

Microph phone + INA110 + PGA2500 + AD7988

AD7988 is single end input, so I want to adjust PGA2500 level shift to match AD7988 input range 0~5v

Hope my description is clear for you.

Thanks

Best Regards,

Stone

Hi Luis Fernando Rodríguez S.

Thanks for your reply. my application describe as below :
Microph phone + INA110 + PGA2500 + AD7988
AD7988 is single end input, so I want to adjust PGA2500 level shift to match AD7988 input range 0~5v
So I want to adjust level shift to 2.5v on PGA2500 to match AD7988
Hope my description is clear for you.
Thanks
Best Regards,

Stone

Hi Stone,

In order to adjust the level shift of the PGA2500 to 0~5, it is necessary to adjust the VcomIN pin level. You may take a look of the Operation with VcomIN=+2.5V Section of PGA2500 datasheet for more details.

I hope this helps you. If you still have questions, please let me know.

Best regards,

Luis Fernando Rodríguez S.

Hi Luis Fernando Rodríguez S.
thanks for your reply. I had read this topic of VcomIN. And I tried.
When I input 2.5v to VcomIN, but it is not work in outside level shift.
So I do not which part have problem. Can you help me to find the point?
Is it setting or other problem?
Thanks
Best Regards,
Stone

Hi Stone,

Could you provide more information about the connection between your components like a schematic or the pins that your routing or using? Have you acquired a signal at the input of PGA2500? If so, could you describe its characteristics? Finally, if you are configuring the PGA with the Serial Port Protocol, could you provide the value of the control word that you wrote?

Thank you.

Best Regards,

Luis Fernando Rodríguez S.

Hi Luis Fernando Rodríguez S.
I am Stone. About you request more information.
I scribe as below
1.first input of PGA2500, I input single end signal(mean In+ is signal+; in- in ground)
out+ i s signal out+; out- is ground); and I try to input 2.5v into Vcomin
for this structure, Is or not I can get a level shift 2.5v in out?
2. microphone + INA110 + PGA2500
about the SPI setting as below:
DCServoEnable = 1;
User_PGA2500.CMServoEnable = 1;
User_PGA2500.OverloadIndicatorBit = 0;
User_PGA2500.GPIO = 1;
AGCgain = User_PGA2500.GAIN = 31;

because this area of discussing can not post circuit map, if it is not clear.
Please give me a reference circuit of PGA2500 which use single-end and with vcomin to level shift.
thanks
Best Regards,
Stone

hi Luis Fernando Rodríguez S.:
sorry, I am stone again. About the detail information as below
1. first my system is
microohone + INA110(pre-amp) + PGA2500 (vcomin inout 2.5v+ AD7988, signal is single-end. So the IN- and out- connect to ground.

2.SPI setting as below
DCServoEnable = 1;
CMServoEnable = 1;
OverloadIndicatorBit = 0;
PGA2500.GPIO = 1;
AGCgain = User_PGA2500.GAIN = 31;

But the out of PGA2500 do not level shift 2.5v.
if my desciption is not clear, please give me reference circuit which use Vcomin to make level shift.
Thanks
Best regards,
Stone