150 µF bulk cap for low-impedance rails
The TPSE157K010R0100 is a 150 µF molded tantalum capacitor from the TPS series, rated at 10 V with a 100 mOhm ESR. That ESR figure is the one that matters for a bulk decoupling decision — at 100 mOhm it handles ripple current without self-heating that would push the part past its derating curve. In a 3.3 V rail feeding an FPGA core, this cap sits between the regulator output and the local MLCC bank, catching the low-frequency transient energy the ceramics cannot store. The 2917 case (7343 metric) is a standard footprint for high-capacitance tantalums — the same pad pattern used across the TPS family, so a BOM swap between capacitance values within the same case code needs no layout change. Seated height is 4.30 mm max, which clears most 5 mm board-to-board standoffs.
What the 100 mOhm ESR buys you on a real board
100 mOhm ESR at 10 V rated means the capacitor can absorb a ripple current of roughly 1.2 A RMS before the internal temperature rise hits the 125 °C ceiling — assuming the board ambient is below 85 °C. For a buck converter switching at 500 kHz, that ripple current budget covers the inductor ripple plus the output capacitor's share of the AC current. If the load step is faster than the regulator's loop can respond, the 150 µF bank supplies the charge until the loop catches up. Tantalum capacitors need voltage derating — a 10 V part on a 5 V rail gives 50 % margin, which is the rule of thumb for avoiding field failures from surge current. The molded package (EIA case code E) has a solid manganese dioxide cathode; it does not have the ignition failure mode of polymer tantalums, but it still needs the derating headroom.
Active — no end-of-life clock ticking
The 125 °C ceiling is the absolute maximum case temperature — derate the ripple current above 85 °C per the standard tantalum derating curve.