Because of the Thanksgiving holiday in the U.S., TI E2E™ design support forum responses may be delayed from November 25 through December 2. Thank you for your patience.

  • State Resolved
  • Locked Locked
  • Replies 1 reply
  • Subscribers 64 subscribers
  • Views 93 views
  • Users 0 members are here
Support feedback
Options
Options
Similar topics

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TPS51518: D-CAP and D-CAP2

R.Fukunaga
Expert 1545 points
Part Number: TPS51518
Other Parts Discussed in Thread: TPS51219

Tool/software:

Hi all,

I would like to compare the advantages and disadvantages of D-CAP and D-CAP2.

I couldn't understand by looking at the data sheet and previous thread on E2E below.

(+) What is the differnce of DCS-control and D-CAP? - Power management forum - Power management - TI E2E support forums

1) What is the difference between D-CAP and D-CAP 2? Should I choose TPS51518 or TPS 51219?

2) D-CAP is described as "for Fast Transient Response". Is D-CAP2 inferior in transients? Or is it equivalent?

3) D-CAP2 is described as "for Ultra-Low/Low ESR Output Capacitor". Can't D-CAP use a high ESR capacitor? Can't D-CAP use a low ESR capacitor?

Best Regards,

Ryusuke

  • +1
    TI__Intellectual 1680 points

    Hi Ryusuke,

    1. D-CAP is a more basic control loop with just one transconductance amplifier. D-cap2 builds upon D-cap and adds a phase compensation network. This network will scale the ripple component of the inductor information and use it in conjunction with the voltage feedback to achieve loop stability. 

    2. Both are good for transients, D-cap2 is better. 

    3. D-cap and D-cap2 can be used with both high and low ESR caps so long as the design requirements described in the datasheet are met. This is to help ensure loop stability and reduce jitter. D-cap2 is meant to be used with MLCC's since MLCC's typically have very low ESR.

    FYI, both TPS51518 and TPS51219 have both D-cap and D-cap2 operation modes. Primary difference between these two parts is the operation frequency. 518 is 350kHZ for both D-cap and D-cap2 modes while 219 will operate at 250kHz in D-cap mode and 500kHz in d-cap2 mode.

    Hope this helps.

    Best Regards,

    Nash