Are Polymer Capacitors Worth Using?

For the last few years, polymer capacitors are getting increasingly popular in electronics. This is not surprising since they have some significant advantages over traditional aluminum electrolytic or tantalum capacitors.

In the case of tantalum capacitors, a major benefit polymer versions provide over standard tantalum capacitors is the extremely low ESR (and high ripple current). They also have lower derating of %20, compared to %50 of regular MnO2 tantalum capacitors. To give an example, for a 5V power rail, it is recommended to use a tantalum capacitor with a 10V rating while this reduces down to 6.3V with tantalum polymer capacitors. These benefits combined with the removal of ignition failure possibility made the tantalum polymer capacitors the preferred choice for power supply output rails for many applications.

                                                                                                 Failure of a tantalum capacitor.

Similar things can be said for aluminum polymer capacitors as well. They have lower ESR and ESL values and significantly higher lifetime (especially at lower temperatures) compared to aluminum electrolytic capacitors.

                                                              From Würth Elektronik Application Note: ANP071

In our designs, we prioritize using polymer capacitors over their regular variants as we think their advantages outweigh their drawbacks. Only polymer capacitors are used in our DSBOARD-NX2 and upcoming DSBOARD-XV2 products.