Some questions about AFE0064.

user3918960

Other Parts Discussed in Thread: AFE0064

Hi, I decided to use afe0064 to design a project. When I go to design the Schematic. I meet a problem.Whether it is diferent that i connect the GND pins to Analog ground or digital ground? The datasheet just tell that "ground for device power supply" .If the AD that I used has analog ground and digital ground ,in order to achievea better performance, should I connect the GND to analog ground or digital ground?

over 10 years ago

0 Adam Sidelsky over 10 years ago

TI__Guru 65420 points

Hello,

I am already researching this for you in another thread, please allow me time to get your answer.

Regards,

-Adam

0 user3918960 over 10 years ago in reply to Adam Sidelsky

Prodigy 180 points

Thanks for your reply.I will be very grateful for your notification when you get my answer.

0 Adam Sidelsky over 10 years ago in reply to user3918960

TI__Guru 65420 points

Hello,

It is better to connect all the grounds of the afe0064 to the analog ground. By that, it means “not the FPGA or PC ground”. It is assumed that all other critical circuitry (like references, power supplies, sensors) are referenced with respect to this analog ground.

Regards,

-Adam

0 user3918960 over 10 years ago in reply to Adam Sidelsky

Prodigy 180 points

Thanks for your answers. I have another question about afeoo64.That is the afe0064 is operated at Higher Scan Times as shown in Figure 7 in the datasheet, if the device ouput stays at 3-state or keeps outputing the analog signals during the 'Additional 133 clocks" ,if I tie ENTRI pin to a high level?

0 Adam Sidelsky over 10 years ago in reply to user3918960

TI__Guru 65420 points

I am looking into this and will get back to you.

0 Adam Sidelsky over 10 years ago in reply to Adam Sidelsky

TI__Guru 65420 points

Hello,

The ENTRI pin only tri-states the output while the EOC pin is also HIGH. This means that during the "additional 133 clocks" when EOC is LOW, the ENTRI pin will have no effect. The output during the 133 clocks will not be tri-stated and the data will also not be valid and needs to be ignored.

Regards,

-Adam

0 user3918960 over 9 years ago in reply to Adam Sidelsky

Prodigy 180 points

Hi,Adam. I am testing an AFE0064 now . I met one question .First ,I show the output of AFE0064 in the follow picture. The AFE0064 is setted as flow: ENTRI = 1;NAPz =1; SMT_MD =1; PDZ= 1;INPUTz =1; PG2-0=011 (1.2pC).The input current is none. From the datasheet I konw the output should be that OUTM1 =2.25V,OUTP1 = 0.85V. But from the output of AFE0064,it sames that only the first 16 pionts is right (OUTM1 - OUTP1 =1.4V). the other 16 pionts is very strange. Specially, the OUTP1 is strange. Once I have tested other AFE0064. the two chips have the same setting and use the same code, the other one is OK. I find the the OK one is OAADSRW AFE0064 .The one that have problem is 13AN6DW AFE0064.The two have different model. I Wonder if it have samething with the model of AFE0064 ?

0 Adam Sidelsky over 9 years ago in reply to user3918960

TI__Guru 65420 points

I have seen your post in another thread and will answer there: e2e.ti.com/.../480179

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Some questions about AFE0064.