What the 60 dB PSRR at 100 Hz means for your rail
The TLE4295GV26 is a fixed 2.6 V output LDO from Infineon's automotive-grade portfolio, rated for 30 mA continuous output. Its headline spec is 60 dB power-supply rejection ratio at 100 Hz — that's the fundamental of a rectified 50/60 Hz line, so the regulator attenuates ripple from an alternator or a switching pre-regulator by a factor of 1000 at that frequency. For a 100 mVpp ripple on the input, the output sees roughly 100 µVpp. The 45 V maximum input voltage covers the full automotive transient envelope — load-dump pulses up to 40 V and cold-crank dips to 4.5 V are within the operating range without an external clamp or pre-regulator. Dropout is 0.4 V max at 20 mA, so a 3.3 V rail feeding this LDO leaves 0.7 V headroom at full load.
Thermal and protection — why this survives an engine bay
The -40 to 150 °C junction temperature rating matches AEC-Q100 Grade 0 — the part is specified for under-hood ambient temperatures that hit 125 °C with self-heating margin. The protection set includes reverse polarity, overcurrent, overtemperature, short-circuit, and antisaturation — the antisaturation feature prevents the pass transistor from entering deep saturation during dropout, which reduces output overshoot when the input rail recovers. Quiescent current is 200 µA typical — not the lowest in class, but low enough for an always-on ECU module that draws microamps in sleep. The 4 mA maximum supply current is the total drawn by the internal bias circuits; it sets the floor for the regulator's own power dissipation at light loads.
Package and PCB integration
The PG-SCT595-5 package is a 5-lead SMD with gull-wing leads, not a standard SOT-223 or DPAK. The lead pitch and pad layout differ from common automotive LDO packages — the PCB footprint must match the supplier device package drawing exactly. The single regulator output is fixed at 2.6 V, so no feedback resistor divider is needed; the Power Fail control feature provides a flag output when the input drops below the regulation threshold.