SPRAC31 February   2019 TMS320C5505 , TMS320C5515 , TMS320C5535

 

  1.   TMS320C5505/15/35/45 schematic checklist
    1.     Trademarks
    2. 1 Introduction
      1. 1.1 Device Applicability
      2. 1.2 Links to TI Hardware Designs Based on C5505/15/35/45
        1. 1.2.1 C5505 eZdsp
        2. 1.2.2 C5515 eZdsp
        3. 1.2.3 C5515 EVM
        4. 1.2.4 C5535 eZdsp
        5. 1.2.5 C5535 Audio Capacitive Touch BoosterPack
        6. 1.2.6 C5545 BoosterPack (BOOST5545ULP)
      3. 1.3 EVM vs Data Sheet
    3. 2 Complimentary Resources
    4. 3 Recommendations Specific to C5504/05/14/15/32/33/34/35/45
      1. 3.1  Before You Begin
        1. 3.1.1 Documentation
        2. 3.1.2 Pin Out
      2. 3.2  Unused Pins
      3. 3.3  Unused Power Rails
        1. 3.3.1 If USB is not Used
        2. 3.3.2 If RTC is not Used
        3. 3.3.3 If EMIF is not Used (not applicable to C5532/33/34/35 or C5545)
        4. 3.3.4 If an On-Chip LDO Output is not Used
      4. 3.4  Clocking
      5. 3.5  OSC Internal Oscillator Clock Source
      6. 3.6  Power
        1. 3.6.1 CVDDRTC Must be Always Supplied - [0.998 V - 1.43 V]
        2. 3.6.2 LDOI Must be Always Supplied
        3. 3.6.3 On-Chip LDOs
        4. 3.6.4 Recommended PMIC
        5. 3.6.5 DVDDIO Supply ON While CVDD OFF
        6. 3.6.6 Power Sequencing
        7. 3.6.7 Voltage Rails of IO Pins
      7. 3.7  Decoupling Capacitors
      8. 3.8  LDO Output Decoupling Capacitors
      9. 3.9  Digital GND, Analog GND, Local GND
        1. 3.9.1 Recommended USB Supplies
      10. 3.10 Reset
      11. 3.11 USB
      12. 3.12 I2C
      13. 3.13 I2S
      14. 3.14 RTC
      15. 3.15 SAR ADC
      16. 3.16 Pin Muxing
      17. 3.17 Signal Visibility
      18. 3.18 EMIF (not applicable to C5532/33/34/35 or C5545)
      19. 3.19 JTAG
      20. 3.20 Bootloader
    5. 4 References

3.6.3 On-Chip LDOs

  • Pros: Included in DSP package (reduced board size and cost), On-chip POR voltage monitor and POWERGOOD holds RESET, ability to switch CVDD voltage by writing to LDOCNTL register
  • Cons: Better conversion power efficiency available with off-chip regulators (switching), LDOO cannot supply CVDDRTC - still need external [0.998 - 1.43] supply (or voltage divider/diode)
  • Before reset is released, LDOs ramp up to an untrimmed value. After reset is released, the bootloader trims the LDO outputs to their target voltage. Untrimmed voltages are screened to allow bootloader execution, but may be as low as 1 V. Take this into consideration if monitoring LDO output voltages before releasing reset. Consider asserting RESET for a fixed delay to allow for bandgap and LDOs to ramp to untrimmed values.
  • If not using DSP_LDOO to supply CVDD...

  • Warning: If DSP_LDOO does not supply CVDD (DSP_LDO_EN = HIGH), then no Power-On-Reset logic to hold RESET low internally while CVDD ramps
  • RESET must be held low externally until all power supplies are up and stable
  • Consider POWERGOOD signal timing and tolerance during CVDD ramp - when RESET released, CVDD must be > 0.998 V with margin

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