TI E2E Community
Linear Regulators - Forum
LM117 - output capacitor question
LM117 Protection Diodes The LM117 datasheet states the following "When an output capacitor is connected to a regulator and the input is shorted, the output capacitor will discharge into the output of the regulator. The discharge current depends on the value of the capacitor, the output voltage of the regulator, and the rate of decrease of VIN. In the LM117, this discharge path is through a large junction that is able to sustain 15A surge with no problem. This is not true of other types of positive regulators. For output capacitors of 25 μF or less, there is no need to use diodes." Does this apply to all types of capacitors including those with virtually no ESR, such as ceramics, or does it only apply to types of capacitors with an appreciable amount of ESR such as tantalums?
LM317-n; Literature Number: SNVS774L
This applies to all capacitor types.
The lit # points to the datasheet. Did you intend to point to an applicaion note?
"... Did you intend to point to an application note? ..."
No. My intent was only to specify which of the several LM317 datasheets this is for, so that there is no confusion.
Datasheet SNVS774L contains the quote, that's the literature # that I referenced.
Datasheet SLVS044U does not contain the questioned quote, so anyone looking at SLVS044U, and believing that SLVS044U is the only LM317 datasheet available, will not have any idea what this thread is about.
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.