I am using a DCP020515D to convert 5V to 15V. I would like to minimize the output voltage ripple to under 15 mV if possible. Can TI recommend any output capacitor (possibly 10uF with low ESR from my calculations) that would do the job assuming that the input voltage is perfectly flat. Thanks
I attached a PI filter using ceramic capacitors and ferrite beads( 1-5uH) for this request.The average ripple reduction is 10 -15db.
Thanks for the solution.
1) Is there a maximum ESR that the caps should have.
2) Does the size of the decoupling caps used at the loads matter?
I attached part of the design that uses the output.
Thanks for the response .
1. The ESR on ceramic capacitors at this switching frequency is typically 3-6mΩ.
2.The ideal decoupling capacitors are ceramic types with X5R and X7R tolerance rating with 1.0uf to 4.7uF .Do not use Z5U or lower tolerance ceramic capacitors due their poor temperature ratings.
Ok sounds good. I will try it out. Thanks,
the post is already some months old but I have a question concerning the DCP02 series ripple filtering, too. I already wrote Tom an Email, but maybe it's better if I post it in the forum too:
There is one specific question which wasn't answered in different posts: What's about the Y-Capacitor between input GND and output GND? Other DCDC Manufactures propose this capacitor with high voltage durability and low capacity (2.2nF - 100nF).In our tests it was shown, that this capacitor has much more positive effects than all PI-filtering at the input or output side of the DC/DC-Converter.Does TI also recommend this GND/GND coupling? What's about the galvanic isolation? Are there any side effects that come with this coupling?
Thank you very much for your help!RegardsChristoph
The isolation coupling capacitor between Vin(-) and Vout(-) can be used for reducing EMI and reflected ripple. However, the voltage rating should be equal or greater than the converter 1 second isolation test or 2000V. The design of the DCx converters is fro ground fault isolation applications.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.