This TAJC476K020RNJ is a 47 µF molded tantalum capacitor rated at 20 V — a common bulk-decoupling value for 12 V intermediate buses and 5 V supply rails, with enough headroom to handle 12 V plus a 10 % tolerance margin.
500 mOhm ESR — ripple-current limit in PSU outputs
At 500 mOhm ESR, this cap dissipates about 0.25 W at 700 mA ripple current — enough for a point-of-load filter on a 3 A regulator, but not for a high-ripple input stage. The ESR also sets the output ripple voltage: 500 mOhm × ripple current gives the AC drop across the cap. For a switching regulator running at 500 kHz, the 500 mOhm ESR dominates the impedance at the switching frequency — the ceramic bypass cap on the output handles the higher-frequency content.
Rated from -55 to 125 °C, this cap lives in the same temperature band as military and aerospace silicon — avionics black boxes, downhole logging tools, satellite power supplies, and engine-bay ECUs all run in this range. The 125 °C ceiling means the cap can sit next to a hot MOSFET or regulator without derating the voltage — tantalum caps do not lose voltage rating with temperature the way ceramics do.
2312 case — common footprint for 47 µF/20 V
The 2312 metric case (6.00 mm × 3.20 mm, 2.80 mm seated height) is a standard tantalum footprint shared across multiple manufacturers — the land pattern matches the EIA 6032-28 pad geometry. Manufacturer size code C confirms the case dimensions; the 0.110-inch seated height fits under most low-profile heatsinks or enclosure lids.