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TMS320F28379D: Can we use TPS7A88-Q1 to power TMS320F28379D?

Prodigy 40 points

Replies: 5

Views: 61

Part Number: TMS320F28379D

Hi,

We are planning a custom board for BLDC motor drive application.

1. Can we use TPS7A88-Q1 to power TMS320F28379D? Is there any reference schematic with 5VDC i/p and 3.3VDC & 1.2VDC outputs. 

2. Also can we use the same 3.3V power to level translation IC SN74LVC8T245/ crystal oscillator/ TPD4E001/ Quad opamp and THVD1452 transceiver?

  • In continuation to above,

    3. How is the accuracy of ADC impacted if we use the same 3.3VDC power to VREFHIA/B/C/D? Given that all possible measures as suggested in F28379D control card and launchpad (inductors and decoupling capacitors) will be taken.

  • In reply to Sandhya Bhagvath:

    Hi Sandhya,

    For (3), if you connect VDDA to VREFHI, the ADC will work.  PSRR will become 0dB and the ADC results will in general be pretty noisy.  Accuracy will be accuracy of your LDO + accuracy of the ADC. 

    In general, this is OK if you are just using the ADC for some rough system monitoring type sensing where timing and accuracy aren't critical and you can just average-out the additional noise by massively over-sampling all the ADC inputs.  I wound't recommend this if you need the DS rated ADC speed + performance; in that case you'll definitely want to use something similar to the circuit suggested in the TRM section "Designing an External Reference Circuit".   

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  • In reply to Devin Cottier:

    Thanks Devin. Since I am using the ADCs for current sensing, I will go for external reference as suggested. Thanks again.

    Can someone please comment on:

    1. Can we use TPS7A88-Q1 to power TMS320F28379D? Is there any reference schematic with 5VDC i/p and 3.3VDC & 1.2VDC outputs. 

    2. Also can we use the same 3.3V power to level translation IC SN74LVC8T245/ crystal oscillator/ TPD4E001/ Quad opamp and THVD1452 transceiver?

  • In reply to Sandhya Bhagvath:

    Hi Sandhya,

    Please refer to the control card design in C2000Ware

    C:\ti\c2000\C2000Ware_3_01_00_00\boards\controlCARDs\TMDSCNCD28377D\R1_1_A\F2837x_180controlCARD_R1_1_a_SCH_09May2014

    Regards,

    Nirav

  • In reply to Nirav Ginwala:

    Thank you Nirav.

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