Tantalum Capacitor Vs Electrolytic Capacitors

[gokugohan]

Hi all,
I need to know whether i can use a tantalum capacitor instead of electrolytic capacitor?
Scenario is, I am getting constant 5V, 2A DC supply from a regulator. Now, i need to use this power supply to power up my micro which works on 3.3V DC. So, i am using a 3.3 Voltage regulator to power up my controller. As i need to make my pcb as small as possible, i though of using 10uF/63V Tantalum Capacitors instead of 10uF/63V Electrolytic capacitors.

Am i in the correct path? Please guide me with this.

 

[barry]

You need to check the specifications of your regulator. Some of them have a minimum ESR requirement on the cap to maintain stability. If the tantalum is suitable in your case, then go for it, but you don't need a 63V part, a 16V part would suffice. Also, you might investigate using a ceramic cap instead of the tantalum.

 

[abhi_tandon80]

i agree with barry ,but normally failure mode of component also need to be verify before applying in power supply ,whether short circuit or open circuit ,tantalum fails as short circuit

 

[schmitt trigger]

To covert from +5 to +3.3 volt you definitively require a low dropout regulator (LDO).
Earlier LDOs were extremely sensitive to output capacitor ESR. They had plots and graphs of the proper capacitance/esr values vs output current before instability occurred.

More modern regulators have alleviated this requirement, although not completely eliminated it.

Some vendors, like TI, offer regulators that are stable with ceramic chip caps, which you'll be able to get them in smaller packages than a tantalum.
for instance:
https://www.ti.com/product/lp38690

There are many more.

 

[crutschow]

To pick a nit, tantalum capacitors are electrolytic capacitors. The two common types of electrolytic capacitors are fabricated with either aluminum or tantalum. Tantalum electrolytics generally have longer life and lower ESR than aluminum electrolytics.

 

[liteon]

Another factor for selecting either tantalum or aluminum is costs.Tantalum caps are costly.And commonly available in low voltage ratings.In fact i personally have never seen one with a voltage rating higher than 16v.Although higher voltage ratings may be available but i am sure they will cost heavily to purchase.
By my experience tantalum caps are bad candidate for use in voltage regulation applications,They require pretty stable filtered voltage for themselves to perform flawlessly.
Spikes are the worst enemy of tantalum caps,They cannot under no circumstances withstand spikes and die for sure.