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

3.1.2 Pin Out

Internal pull-up/pull-down resistors are implemented with weak transistors. As the voltage present on the I/O pin varies the relative gate voltage to this weak transistor changes which will cause the effective pullup/ pull-down resistance to change. Therefore, internal resistors do not have a linear response like external resistors. The non-linearity along with process voltage and temperature variations require internal pullup/ pull-down resistors to be specified with a wide range of resistance or current sourcing/sinking. The input current without a pull-up or pull-down turned on defines the input leakage without any current from internal pull resistors. The input current with a pull-up or pull-down turned on defines a combination of input leakage current and current required to force the internal pull resistors to the opposite voltage rail. For example, if an internal pull-up is turned on the value shown represents the total current required to pull the input to VSS.

When deciding what value of external resistor to use, you must consider the worst case combination of all internal leakage paths of all devices connected to a signal and make sure the external resistor is able to force these internal leakage paths to a potential greater than Vih min, or less than Vil max.