• State Resolved
  • Locked Locked
  • Replies 2 replies
  • Subscribers 82 subscribers
  • Views 1471 views
  • Users 0 members are here
Support feedback
Options
Options
Related

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.

How many ADC channels are on LAUNCHXL-F28377S?

BENFEI WANG
Prodigy 190 points

I have implemented my control algorithm on F28335, and now I want to transplant the codes to F28377. Then I find a develop board of  named  LAUNCHXL-F28377S. 

Because I have to utilize up to 7 ADC channels, I want to confirm  how many ADC channels are on  LAUNCHXL-F28377S board. I go through the datasheets of F28335, F28337S and LAUNCHXL-F28377S,  the description are in different formats as follows:

1. F28335: "12-Bit ADC, 16 Channels"

2. F28377S: "Up to Four Analog-to-Digital Converters, Up to 24 External Channels"

3. LAUNCHXL-F28377S: no specified description, but the schematic shows that there are several ADC pins from ADCINA0~A5; ADCINB0~B5.

Moreover, I also look at the description of the ADC in F28346 which is shown below:

3.F28346:"External ADC Interface"

-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

After reading these descriptions, I am confused. My questions are listed as follows:

1. How many ADC channels of F28377s?

2. How many ADC channels of LAUNCHXL-F28377S?

3. What is the difference between "ADC converter" and "ADC channel" ?

4. What is the difference between "external ADC channel" and "external ADC interface"?

It will be very appreciated if you can help me to figure out the answers. Thanks.

  • 0
    TI__Guru 60865 points

    Hi Benfei,

    F28377S device itself has a different number of ADC channels depending on the package selected.  You can see these in the datasheet here:

    The launchpad uses the 100-pin package, so the maximum number of pins would be 14.  Looking at the pinout, you can see that these are all available on the connectors:

    ADC converter is a separate ADC module, while ADC channel is an ADC input pin. 

    The F28335 has a singe ADC, which can do simultaneous sampling.  When simultaneous samples are captured, they are processed through the single ADC sequentially.  

    The F2837x family of devices has as many as 4 separate ADC modules (each can only do single sampling).  This allows up to 4 samples to be captured in parallel, and then the 4 samples can also be processed in parallel. These ADCs are lettered: ADC-A, ADC-B, ADC-C, and ADC-D.  On the 100-pin package, only pins from ADC-A and ADC-B are pinned out, so only 2 ADCs are actually available.  

    External ADC channel refers to an ADC input pin.  In addition to the 14 ADC input pins, there are also internal signals you can sample with the ADCs: temperature sensor and VREFLO.  These use a dedicated mux position for a given ADC, but there is no physical external pin.  

    External ADC interface is a digital interface that allows you to trigger a discrete ADC that you have connected to the device digital pins. 

  • 0 in reply to Devin Cottier
    Prodigy 190 points
    Dear Devin

    Great! Thanks for your patient explanation.