Active production — 200 mA LDO with ultra-low noise floor
The LT3042EDD#PBF is an active-production adjustable positive LDO from Analog Devices, rated for 200 mA continuous output. Its defining parameter is the PSRR curve: 117 dB at 120 Hz, tapering to 56 dB at 10 MHz — a noise-rejection envelope that spans the full audio band and well into the switching-frequency range. For a sensitive analog front-end or a precision ADC supply rail, that means the regulator itself contributes negligible ripple from the upstream rail.
Dropout and input headroom — 0.35 V at full load
Maximum dropout is 0.35 V at 200 mA (typical), so the input rail must stay at least that margin above the set output voltage across load and temperature. With a 20 V absolute maximum input, the part can regulate down to 0 V (adjustable) up to 15 V max output.
Control and protection — Enable, Power Good, reverse polarity
Control features include a dedicated Enable pin, a Power Good flag, and current limit. Protection covers over-temperature shutdown and reverse polarity — the latter is unusual for a linear regulator and saves an external Schottky if the input rail can swing negative during power sequencing. The part is ROHS3 compliant per the lifecycle record.