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xy_283156
Level 2
Level 2

Hi, i have a problem with a opamp:

   

when i don't starting the amp with "opam_start();" in my initialization function there's no problem and it works fine,

   

but if i do including the "opam_start();" the amp don't works. Which components do i have to start explicit with..._start() and which starts automatically?

   

Thank you

   

Im using the Creator 2.1 Pack 4.

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1 Solution
ETRO_SSN583
Level 9
Level 9
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Looks like you are going to use OpAmp for a TIA, so why not use a TIA from Creator ?

   

 

   

   

 

   

 

   

 

   

 

   

Regards, Dana.

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16 Replies
ETRO_SSN583
Level 9
Level 9
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I tried this, and start is required.

   

 

   

You typed "opam_start();", is your Opamp component named opam, or

   

is it named "Opamp" or is it named "Opamp_1" ?

   

 

   

The start commands would look like (associated with above names) -

   

 

   

opam_Start();

   

Opamp_Start();

   

Opamp_1_Start();

   

 

   

Capitaization matters.

   

 

   

Regards, Dana.

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xy_283156
Level 2
Level 2

Thanks,

   

but it seems that this is not the problem. Shouldn't the complier gives a error message, if i do mistakes like this?

   

Which Konfiguration has the opamp (and other components too) if i dont start him explicit (with..._Start();),

   

because then it runs quit good!? I could leave it like this but it concerns me a little bit.

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Most analog  modules and half the digital ones need a Start() - command. Best is to peep into the datasheet, section APIs where the initially necessary calls are listed first.

   

 

   

Bob

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Modules that need a Start() are not working correctly as long as they are not initialized. Their default state is powered off. When you mis-spelled an API you will be informed by the compiler, as you said.

   

To give us the chance to check your complete settings will you please use the "Create Workspace Bundle" (minimal) and upload the resulting archieve here. This may clarify everything for us.

   

 

   

Bob

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xy_283156
Level 2
Level 2

hmm , for me it seems like the opamp is only starting when i add no API-code, if i a add the code he do nothing?

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xy_283156
Level 2
Level 2
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xy_283156
Level 2
Level 2

The "Trigger " is for flashing an LED, on the opamp is an photodiode - it works fine untill i uncommend line:

   

    //Mess_Opamp_Start();    //Here's the Problem!?

   

Thanks for help

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Bob_Marlowe
Level 10
Level 10
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The inside of the PSoC looks OK.

   

what is connected to the 3 pins, any feedback on the OPA1-pins externally?

   

 

   

Bob

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ETRO_SSN583
Level 9
Level 9
250 likes received 100 sign-ins 5 likes given

Looks like you are going to use OpAmp for a TIA, so why not use a TIA from Creator ?

   

 

   

   

 

   

 

   

 

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
Level 9
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Note, you may be able to take enough G in TIA to eliminate PGA, which would

   

enhance noise performance as well.

   

 

   

Regards, Dana.

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ETRO_SSN583
Level 9
Level 9
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I built your design in 2.2 and it compiled properly with Mess_Opamp_Start();

   

 

   

Regards, Dana.

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xy_283156
Level 2
Level 2

Of course i could use a TIA but i need the blocks for Sample&Holds. The opamp with external resistor works fine, untill i start the amp with ..._Start()...?

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ETRO_SSN583
Level 9
Level 9
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Ordinarily I would recommend you post as a tech case at -

   

 

   

www.cypress.com

   

“Support”

   

“Technical Support”

   

“Create a Case”

   

 

   

but where it compiled w/o error in 2.2 you might consider updating

   

to 2.2. I looked at release notes for 2.2 to see if some applicable

   

error was fixed, found none, but did not look at 2.1 known errors,

   

you might look at that.

   

 

   

Regards, Dana.

   

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ETRO_SSN583
Level 9
Level 9
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You can always juggle blocks, by making S/H out of OpAmp as hold

   

cap buffer, 2 in mux, one channel input, other ground to reset cap,

   

output to cap, cap external. Downside is eats up pins, upside longer

   

hold times, less droop.

   

 

   

Just a thought if using internal TIA was more robust solution.

   

 

   

Regards. Dana.

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xy_283156
Level 2
Level 2

It seems that it has something to do with the power mode register,  but i'm not very familiar with the registers. Can anyone tell me how i make sure that the power mode is set to active?

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Bob_Marlowe
Level 10
Level 10
First like given 50 questions asked 10 questions asked

Well, maybe I'm repeating myself, but the powermode will be set automatically when you call the OpAmp:Start() function. This will start the component with the power mode given in the properties of the OpAmp.

   

A second choice would be to use the OpAmp_SetPower() call. There is no need to use access to registers which might have unwanted side-effects.

   

And trust such an often-used component such as the opamp.

   

Take for sure: The component is O.K

   

Your code (as I've seen) is correct.

   

What is left is your schematic which we or (rather: Dana) could check and the actual wiring that you will have to check.

   

 

   

Bob

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