2.2 µF, 16 V — the bypass capacitor for 12 V rails
The TPSA225K016X1800: Rated at 2.2 µF with a 16 V working voltage, this molded tantalum capacitor fits 12 V power rails with 33 % derating margin — standard practice for tantalum to avoid surge failures. The ±10 % tolerance keeps the effective capacitance within 1.98–2.42 µF over the operating range. The 1.8 Ohm ESR at 100 kHz sets the ripple current ceiling: for a 100 kHz switching regulator, the self-heating from ripple current stays manageable below ~200 mA RMS. Higher ripple demands a lower-ESR part or a larger case size.
Capacitance drift over this range is typically within ±10 % of the 25°C value for the TPS series.
1206 case — board layout fit
Housed in a 1206 (3216 metric) molded case measuring 3.20 mm x 1.60 mm with a seated height of 1.80 mm, the TPSA225K016X1800 uses the standard A-size code footprint. The molded construction provides mechanical stability and moisture resistance for reflow soldering.