Wide-input LDO for always-on and battery-powered rails
The TPS70918DRVT is a 150 mA low-dropout linear regulator from Texas Instruments, delivering a fixed 1.8 V output from an input range up to 30 V — wide enough to handle unregulated supplies like 24 V industrial buses or multi-cell battery stacks without a pre-regulator. Quiescent current sits at 2.05 µA typical, so the regulator's own draw is negligible in battery-backed applications where every microamp extends sleep life.
What the PSRR figure means for noise-sensitive loads
PSRR is specified as 80 dB at 10 Hz, rolling off to 52 dB at 1 kHz — this means the regulator attenuates low-frequency ripple from the input (like 50/60 Hz rectifier hum or switching pre-regulator ripple) by a factor of roughly 10,000 at 10 Hz, dropping to about 400 at 1 kHz. For a 100 mVpp ripple on the input at 100 Hz, less than 100 µVpp appears on the output — clean enough to power sensitive analog front-ends or RF oscillators without additional post-filtering.
Protection set and temperature range for harsh environments
Built-in protection includes over-current, over-temperature, reverse-current, and under-voltage lockout (UVLO) — the reverse-current block is notable for preventing back-feed into the input when the output is held high by another supply. Operating temperature spans -40°C to 125°C, covering automotive under-hood and industrial enclosure ambient conditions without derating.
Surface-mount assembly with the exposed pad soldered to a PCB copper plane improves thermal dissipation — critical when the 150 mA output is drawn from a high input voltage, where the dropout power is dissipated as heat.