The TPSE687K004R0040: 40 mOhm ESR is the figure that governs ripple current capability and self-heating; for a 680 µF tantalum this is a low-ESR grade, suitable for switching-regulator output filtering where the AC ripple current would overheat a standard-grade part. ±10% tolerance is the standard production band for tantalum electrolytics — adequate for decoupling and most filter poles; a tighter grade would be needed only for precision timing or active-filter poles.
Temperature range and deployment context
Rated -55°C to 125°C operating — this is the full military-temperature band, not a commercial 85°C ceiling. The part can sit on a board in an engine-bay ECU or an outdoor radio head without derating the temperature spec. The E case is the larger body in the TPS series, carrying the 680 µF / 4 V rating without the ESR penalty of a smaller case.
TPS series — what the family tells you
The TPS series from KYOCERA AVX is a low-ESR molded tantalum line positioned for power-supply decoupling and filtering applications where standard tantalums would run hot. The molded case gives consistent dimensions for pick-and-place and good mechanical stability under reflow. Tape & Reel packaging means the part ships on 13-inch or 7-inch reels for automated assembly — no tube or bulk tray handling needed for volume production.