This TPSA335M025R1000 is a 3.3 µF tantalum capacitor rated at 25 V DC, with ±20% tolerance. That 25 V rating gives comfortable headroom on a 12 V or 5 V rail — the derating rule of thumb for solid tantalums is 50% of rated voltage for reliable operation, so you can run it at 12.5 V continuous without stressing the dielectric.
It fits avionics black boxes, downhole instrumentation, and outdoor telecom gear that sees -40°C nights and 85°C days. The molded case keeps moisture out better than a conformal-coated chip, so it's a solid choice for unsealed enclosures.
ESR and ripple current handling
1 Ohm ESR at 25°C means the self-heating under ripple current is manageable — for a 3.3 µF cap on a 100 kHz buck converter output, the ripple current is typically tens of mA, and the internal temperature rise stays under a few degrees. If your design has high-frequency ripple above 500 mA, you'll want a lower-ESR polymer cap, but for general decoupling this is fine.
1206 (3216 Metric) case, size code A. The 3.20 mm x 1.60 mm footprint is a standard size — your existing 1206 pad pattern works, no layout change needed. Height seated is 1.80 mm max, so it fits under low-profile shrouds or mezzanine boards.
No direct equivalent or second-source is listed, but the TPS series is widely stocked.