TLC3578

raquib akolawala

Intellectual 280 points

Other Parts Discussed in Thread: TLC3578, REF5040

Hi,

I am currently designing a circuit using TLC3578 where I have bipolar inputs of range +5V to -5V

In TLC3578 there is REFP REFM which are to connected as per datasheet via 3 capacitors

In the datasheet of TLC3578 it also states to give VREF of 4V (3.96-4.04 range)

Also in the TLC3578EVM family user guide (slau110.pdf) it is mentioned (table2-2) to give 3.3V as reference voltage

This anomaly I have not understood, as to which reference voltage to connect?

Also there is LM4030C-4.096 which can be used for 4.096V reference voltage can this be directly connected or is there any other part I am suppose to use? (i.e. is the VREF strictly required to be in 3.96-4.04 range)

Please can someone clarify the following issues?

Thanks Regards

Raquib Akolawala

over 12 years ago

0 Kevin Duke over 12 years ago

TI__Mastermind 46290 points

Hi Raquib,

For the TLC3578 the reference voltage should be between 3.96-4.04 V, meaning V_REFM is tied to AGND and V_REFP is tied to your reference source. The EVM violates this specification, this is one of the reasons that evaluation kit is no longer orderable.

If you apply 4.096 V and violate the datasheet specification the device should continue to function, but you can expect to see a loss in INL/DNL performance and some potential degradation in other specs.

0 raquib akolawala over 12 years ago in reply to Kevin Duke

Intellectual 280 points

Hi,

Thanks Kevin

PS: sorry for posting in the wrong thread

0 raquib akolawala over 12 years ago in reply to Kevin Duke

Intellectual 280 points

Hi,

Also I was searching for 4.0v reference voltage for TLC3578 but i have found every where 4.096V Voltage reference

can you also please tell how I can solve this?

Or do you have some other evaluation board schematics I can refer?

Thanks Regards

Raquib Akolawala

0 Kevin Duke over 12 years ago in reply to raquib akolawala

TI__Mastermind 46290 points

Raquib,

You could look at using the REF5040 or other similar parts with a trim pin to try to bring the voltage down to the range the TLC3578 is expecting. Or, you could consider using an op amp to buffer the REF5040 (or other reference device) output and apply some attenuation in this phase.

0 raquib akolawala over 12 years ago in reply to Kevin Duke

Intellectual 280 points

Kevin,

Thanks For Reply

using the same

Raquib Akolawala

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