What this LDO brings to an automotive rail
The Texas Instruments TPS74634PQWDRBRQ1 is a 1-A low-dropout linear regulator with a fixed 3.4 V output, designed for automotive power systems that need clean, regulated voltage from a 6 V max input rail. Its headline feature is a PSRR of 53 dB at 1 kHz, rolling off to 30 dB at 1 MHz — enough to suppress switching-ripple from a preceding DC-DC converter feeding a noise-sensitive load like an analog sensor or CAN transceiver. Quiescent current sits at 36 µA, making it viable for always-on modules where battery draw matters. The part is AEC-Q100 qualified and rated over -40°C to 125°C, so it fits under-hood or cabin-ambient environments without derating surprises.
Protection and control — standard automotive set
Enable and Power Good pins give sequencing flexibility for multi-rail power-up schemes. Internal protection covers over-current, over-temperature, and under-voltage lockout (UVLO). No reverse-polarity protection on-chip — if the supply can be reversed, add an external diode.
Lifecycle and sourcing posture
The TPS74634PQWDRBRQ1 is listed as Active and ROHS3 compliant. No end-of-life notice or last-time-buy window is in effect.