150 mA fixed 1.5 V LDO — the dropout and the thermal pad
The Texas Instruments LP3995ILD-1.5/NOPB is a single-output, positive-voltage linear regulator delivering a fixed 1.5 V at up to 150 mA. The 6-WDFN exposed pad package (supplier device package 6-WSON, 2.92x3.29 mm) requires a thermal land on the PCB to pull heat out of the die.
PSRR profile and quiescent current — the noise-vs-battery trade
Power supply rejection ratio is 60 dB at 1 kHz, rolling off to 50 dB at 10 kHz. This means the regulator attenuates upstream ripple by a factor of 1000 at audio frequencies, but the rejection drops above 100 kHz — switching converter noise at several hundred kilohertz passes through unless filtered ahead of the LDO. Quiescent current is 150 µA typical, with a maximum supply current of 200 µA. For a battery-powered sensor waking up briefly to take a reading, the 150 µA Iq is the floor the system draws even when the load is light — it sets the sleep-mode current budget.
Protection, enable, and temperature range
The part includes over-temperature shutdown and short-circuit current limiting. The enable pin lets an upstream GPIO or power-management IC gate the output — when pulled low, the regulator shuts down and draws near-zero current from the input. The input voltage range goes up to 6 V, so it handles a 5 V rail with margin.
Active production — compliance and sourcing
It is ROHS3 compliant. No official successor or pin-compatible alternative is recorded — the 1.5 V fixed output and 6-WSON footprint are the binding constraints for a drop-in replacement.