cancel
Showing results for 
Search instead for 
Did you mean: 

PSoC™ 5, 3 & 1

Anonymous
Not applicable

Dear community,

I have been working with ADC D-S of psoc5lp with no success to amplify 2 diferential signals with 5mVpp as maximum. I have read different documents and I'm very confused about this.

In page 9 of reference document of ADC Delta-Sigma 3.30 the range with Input ± Vref with Vref=1.024V should be: -1.024±1.024= 0V to 2.048. Why in example of CE95271 with the same condition Vref=1.024 on negative pin of ADC, in page 2 says that if positive enter of ADC is 0 the converted value is -1.024 or if is 1.024 the value is 0; so the range doesn't go from 0V to 2.048 as page 9 of ADC Delta-Sigma 3.30 established? then the range to work can support until 2.048 V as a valid value to work???? 2.048 -> 1.024V? Or can I even enter 3V signal with no problem at all? with VDD=5V?

This is very confused, please any help you can provide me will be very appreciated, thanks in advance.

0 Likes
1 Solution
EvPa_264126
Valued Contributor II

It is better to touch once than see 100 times)))

View solution in original post

12 Replies
Vasanth
Moderator
Moderator

Hello Omar

The range can go upto 2.048( 2.044,Vdac max 1.020+1.024). Currently Vdac voltage is 1V. So the maximum value will be 2.024V. The description does not specify about that range. But it is a usable range. Input voltage range is 0-2.024V.

Best Regards,
VSRS

0 Likes
Anonymous
Not applicable

Thanks Vsrs,

With these conditions, ADC with VREF=1.024 and ADC- input=1.024  ADC SIGMA-DELTA  will work like this:

With 0 at ADC+ conversion will be signed to -0.1024V

with 1.024 at ADC+ conversion will be signed to 0

And here is the confusion: if I enter at ADC+ = 2.048V , Can I expect signed result of +1.024V????? or is this out of range???

What happen if I enter 4V at ADC+ input? ADC conversion value will goes to hexadecimal value of 8000 with 16 bits of resolution?

Please help me I'm very confused. Thanks in advance.

0 Likes
Anonymous
Not applicable

Hi Again Vsrs,

So with differential mode and Vref=1.024V but with ADC- input in 0 the range will be 0±1.024 so-----> -1.024 to 1.024 then:

with ADC+ input in 0 result conversion will be 0?

with ADC+ input in 1.024 result conversion will be 1.024?

Then how to get -.1024 value conversion???? what condition produce this? a negative value????

Thanks.

0 Likes
Anonymous
Not applicable

Many thanks for your response, your schematic was very illustrative.

But what happen if Vref=1.024V with ADC- input in 0 the range will be 0±1.024 so-----> -1.024 to 1.024 then:

with ADC+ input in 0 result conversion will be 0?

with ADC+ input in 1.024 result conversion will be 1.024?

Then how to get -.1024 value conversion???? what condition produce this? a negative value????

Thanks.

0 Likes
EvPa_264126
Valued Contributor II

It is better to touch once than see 100 times)))

View solution in original post

Anonymous
Not applicable

Thanks Evgeniy, consider this question solved.

0 Likes
HaHE_2860291
New Contributor II

Hey Evgeniy,

sorry my stupid question, but what is the "RunMean" component in your schematic.

Is this a filter or funktion?

can  you PLEASE  make a short explaination for me as super noob here...

thanks Harry

greetings from Vienna

0 Likes
EvPa_264126
Valued Contributor II

this Simple moving average.

double click on the component:  set Range_of_Filter

Range_of_Filter -determines the buffer size  as a power of 2 (n = 2^Range_of_Filter)

function:

int32 RunMean_Get(int32 Sampl,int32 SIGNAL_SLOPE);

Sampl - new data

SIGNAL_SLOPE - filter re-initialization threshold ( SIGNAL_SLOPE==0 - forced reinitialization )

p.s. I am pleased to remember Vienna - a very beautiful city.

HaHE_2860291
New Contributor II

thanks Evgeniy,

I ´m a little bit overcharged .... , but I will go through....

I meant, how you create the component "RunMean", with what kind of component or so...if I want to do so like you?

thanks Harry

0 Likes
EvPa_264126
Valued Contributor II

you are asking about the creation of a component?

like here:   Creating New component

HaHE_2860291
New Contributor II

omg...

heavy duty

0 Likes