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Original question:

DCAP+ mode control

What is the differnce of DCS-control and D-CAP?

TATSU Numa
Intellectual 800 points


Hi team

 I want to know the detail about DCS-control and DCAP.

Coould you let me know following question?

・Diffence of DCS-control and DCAP.

・I would say that Mid voltage(<20V) DCDC buck regulator mainly have D-CAPmode, but low Low voltage(7V) mainly have DSC-mode DCDC.

    Why does the low voltage DCDC mainly have the DSC-mode?

best regards

TATSU 

  • 0
    TI__Guru 56985 points

      

    Both D-CAP and DCS are variations of Direct Capacitor Sensing Control where the output capacitor is charged with a controlled on-time, then allowed to discharge until the output capacitor voltage decays back to a reference voltage, triggering another controlled on-time.

    DCS and D-CAP use alternate methods to cancel the DC-offset induced by the ramp injection and and valley voltage comparator used for controlling the output voltage.  The result is slightly different mid-band frequency response and DC output voltage accurate parameters.

    Yes, most Mid-Vin products use D-CAPx mode control architectures and most low voltage devices use DCS control.  The D-CAP mode IP is better suited for wider input voltage ranges while the DCS IP is better optimized for low input voltage applications, but the performance of DCS and D-CAP3 are generally similar.

  • +1 in reply to Peter James Miller
    TI__Intellectual 800 points

    Hi Peter

    Thank you for your answer. And I'm sorry my typo..

    I want to know the "difference" of these.

    And I understand that the D-CAPx is suited for wider input voltage ranges and ..... Why is the D-CAPx  suited for wider Vin? 

    best regards 

    TATSU

  • 0 in reply to TATSU Numa
    TI__Guru 56985 points

     

    The differences are related to their internal IP implementation, not their loop or control functionality.

    Mid Vin devices uses D-CAPx because we have D-CAPx IP developed using 20V and 30V process nodes that can be easily reused while DCS would require some new internal circuits to be developed.

    Low Vin devices use DCS because because we have DCS IP developed using 5V and 7V process nodes that can be easily reused while D-CAP would require some new internal circuits to be developed.

    Functionally, the two technologies are similar enough that the IP development for DCS at Mid-Vin and D-CAP3 at Low-Vin is not cost effective.

    DCS control does offer advantages versus D-CAP and D-CAP2 controller, with better ceramic capacitor support than D-CAP and more accurate output voltage regulation than D-CAP2, but DCS and D-CAP3's performance is effectively the same.