Noise rejection for sensitive 1.8V rails
The MIC5309-1.8YD6-TR is a fixed-output LDO from Microchip Technology, delivering 300 mA at 1.8 V with a maximum dropout of 0.2 V at full load — the headroom between the input rail and 1.8 V must stay above 200 mV to maintain regulation. Its PSRR of 90 dB at 1 kHz (dropping to 70 dB at 1 kHz) means upstream switching noise is attenuated by a factor of ~30,000 at 1 kHz — critical for powering analog front-ends, sensor bias, or RF VCO supplies where ripple couples directly into the signal path.
Temp grade and protection set
Built-in over-current and over-temperature protection means the regulator survives a short on the output or a stalled load without external crowbar circuitry — the die self-limits and recovers when the fault clears. The enable pin allows the downstream rail to be sequenced — pulling EN low drops the output to zero and reduces quiescent current to near zero, useful for power-gating in battery-operated designs.
Housed in a TSOT-23-6 (thin SOT-23-6) with a 0.95 mm pitch — the compact footprint fits into space-constrained designs like wearables or sensor modules, but the thermal pad on the PCB must be sized for the 300 mA load at elevated ambient; the RthJA depends on the copper area under the package. Surface-mount assembly with standard reflow profiles — no special handling beyond the MSL rating typical of this package class.
ROHS3 compliant, with no restricted substances above the threshold — no exemption expiry to track for EU-market shipments.