TCs are electrolytic capacitors that use tantalum as the anode material and passivated tantalum pentoxide as the dielectric. The advantages include greater capacitance per unit area and stabler voltage and temperature characteristics than large capacitance ceramic capacitors.

The cathode terminal material differs between the two. Standard TCs use manganese dioxide (MnO2) while conductive polymer types (i.e. ROHM's TCO/TCTO series) feature an organic substance, which is less combustible and provides much lower ESR (Equivalent Series Resistance) characteristics (typically 1/10^th). This makes them ideal for high frequency and large current applications.

An open-function TC is specially constructed using a thermally sensitive wire to connect the die to the frame that acts like a fuse to prevent smoking and possible flames from being generated due to excessive heat caused by overcurrent.

Since tantalum capacitors are polarity based, smoking or flaming may occur due to short-circuiting, which will generate a significant amount of heat.

The lifetime of TCs is not clearly defined, since the normal factors that contribute to aging – drying up or leaking of the electrolyte in aluminum electrolytic capacitors.

The products are guaranteed for a period of one year from the date of shipment from ROHM, provided they are stored under to following recommended conditions:

Temperature;5 to 40ºC
Humidity;30 to 70%

TCT/TCFG/TC series: Tape and reel (embossed tape)

TCO/TCTO series: Tape and reel (embossed tape), moisture-proof package

Yes. Halogen-free products are available as well.

The terminals of ROHM’s bottom-surface electrode TCs (TCT/TCTO series) protrude slightly from the edge of the package – unlike competitor products – making it possible to form a good fillet, resulting in superior solderability and junction reliability.

Yes, ROHM's TCs must be derated at temperatures exceeding 85ºC (see graph below). Since the voltage supplied to the TC can take many forms and include transients (and possible overshooting), enough margin must be designed in. Many TC manufacturers are recommending using the TCs at 50% of the rated voltage.

The allowable ripple voltage must take a sine wave shape (see below). For other waveform types, please contact a ROHM representative.
The permissible temperature increase due to ripple voltage/current is 5ºC max. At temperatures above this level the dielectric will begin to deteriorate, resulting in possible short-circuits.

The allowable ripple current is calculated from the following formulas, which take into account ESR and power dissipation, which differ depending on the package type.

P=I²R
I = √(P/R)

Please contact us for the ESR and power dissipation values.

Multilayer capacitors tend to decrease in capacitance as the temperature changes. TCs, on the other hand, are extremely stable under temperature fluctuations (see graph below), simplifying designs.

Yes. Since multilayer ceramic capacitors are effectively piezoelectric devices, the capacitance may decrease when certain voltages are supplied. Furthermore, this behavior varies between production lots and manufacturers, making it impossible to predict. This can lead to IC malfunctions – one reason many users are switching to TCs.

No. Multilayer capacitors, being piezoelectric devices, tend to vibrate at specific voltages. This, along with possible sympathetic vibration with the circuit board, can cause sound generation. TCs, on the other hand, do not vibrate at different loads and voltages, making them ideal for audio/visual applications.