• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Answers 1 answer
  • Subscribers 99 subscribers
  • Views 448 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

AM3354: IO questions

Jan Volkering
Expert 8190 points
Part Number: AM3354
Other Parts Discussed in Thread: LM45, , OPA320

Hi,

 

A customer I support is using  an AM3354 on a board and uses one of the analog inputs to read out a LM45 temp sensor.

There is no buffer amplifier (charge bucket) in between. Do the analog inputs of the AM3354 have internal buffers or is it advicable to add an external buffer?

 

Secondly, what is the maximum sink current of the AM3354 IO pins?

  • 0
    TI__Guru**** 393215 points
    Hi,

    I'm not acquainted with the LM45 output properties, but you must be aware that the AIN pins should not be driven with voltages higher than VDDA_ADC at any time. This is 1.8V maximum input voltage in the standard use case.

    On your second question, please check the DC Electrical Characteristics in the device datasheet. Pin output voltages (Voh and Vol) are specified at certain sink/source currents.
  • 0 in reply to Biser Gatchev-XID
    TI__Expert 8190 points

    Biser,

    I checked the TRM of the AM3554.

    Page 1829 shows a blovk diagram of the ADC.

    There is no internal buffer amplifier in front of the ADC so I recommended to my customer to plase an external buffer amplifier (OPA320)

    THis opamp works from 1V8.