SNVAA98 January   2024 LM25148 , LM74910-Q1 , TPS38700 , TPS389006 , TPS389006-Q1 , TPS628301 , TPS628302 , TPS628303 , TPS6287B10 , TPS6287B25 , TPS746

 

  1.   1
  2.   Abstract
  3.   Trademarks
  4. 1 Introduction
  5. 2 Design Parameters
  6. 3 Schematics
  7. 4 Design Considerations
  8. 5 Front-End Protection
  9. 6 3.3V Always-ON Bias Supply
  10. 7 5V Pre-Regulator Buck Converter
  11. 8 Low-Voltage High-Current Core Rail Buck Converter
  12. 9 On-Board Core Rail Output Load Transient Stepper
  13. 10Multiple Peripheral Rail Buck Converters Sub-Circuits Schematic
  14. 11Voltage Supervisor and Sequencer
  15. 1212-Channel Sequencer Alternative
  16. 13Summary
  17. 14References

10 Multiple Peripheral Rail Buck Converters Sub-Circuits Schematic

Regulators Reg1 through Reg4 use different variants of the TPS62830x regulators, each with a different current rating: available in 1-A, 2-A, and 3-A capable options. TPS62830x provide a fast transient response with small output capacitance. However, depending on the output ripple and load transient requirements, more output capacitors can be added. The total effective output capacitance for each TPS62830x regulator must not exceed 200μF. See data sheet for alternative inductor options, as well as other details.

Additionally, this device family has an excellent EMI performance due to the integrated on-chip noise-filtering capacitors.

At the point-of-load, it can be desired to populate as many of the 3-terminal output capacitors, as needed. 3-terminal output capacitors are not necessarily required, but these tend to have lower parasitic inductance, which can help with high slew rate load steps. These capacitors should be placed close to the point of load (in this test case, near the load board connectors, J18 and J20).

The total effective output capacitance for each TPS62830x regulator should not exceed 200μF. See data sheet for alternative inductor options, as well as other details.

Currently, the Regulator 5 rail for GTAVCCAUX rail is implemented using the TPS74615 linear regulator. The power loss, which is entirely dissipated in the part, at the full load of 50mA is 175mW. If a lower power dissipation (for example, higher efficiency and lower temperature rise) is desired, two Buck switching regulator alternatives to consider using are: TPS629203DRL and TPS62A01ADRL.