Dual 300mA LDO for noise-sensitive 3V rails
The MIC5331-PPYMT-TR packs two 300mA LDOs in a single 2x2mm 8-MLF package, each delivering a fixed 3V output from a 5.5V max input. The 50µA quiescent current per channel keeps the always-on domain draw low in battery-powered designs, while the 240mV max dropout at full load means a 3.3V rail still holds regulation down to 3.24V input — useful when the front-end buck converter sags under transient. The PSRR profile — 65dB at 1kHz dropping to 45dB at 20kHz — covers the switching-noise band of most DC-DC converters. If the upstream switcher runs at 2MHz, the fundamental ripple sees roughly 50dB of rejection; the 20kHz roll-off matters more for audio-band supplies where the 1/f noise of the switcher couples through.
Package and thermal layout for the 8-MLF
The datasheet's recommended footprint uses a 1.7x1.7mm solder-paste aperture on the pad; without those vias the junction-to-board thermal resistance climbs and the 125°C max junction is reached at lower ambient. Enable pins on both channels let the system power down the radio or sensor chain independently. The over-current and over-temperature protection are self-resetting — a sustained short on one output shuts that channel down until the fault clears, without latching the other rail.
The -40°C to 125°C operating range covers industrial and under-hood automotive ambient. The 5.5V absolute-max input means a 5V rail with 10% tolerance (5.5V peak) is at the limit — a 3.6V or 3.3V rail gives headroom for the input capacitor's ripple voltage.