3.0 V fixed LDO in a TSOT-23-5 — what the ratings mean for the rail
The ADP1712AUJZ-3.0-R7 from Analog Devices is a single-output, positive fixed LDO regulator delivering 3.0 V at up to 300 mA. It comes in a TSOT-23-5 package — five pins, no exposed pad, so the thermal path is through the leads and the board copper. The 65 dB PSRR at 1 kHz is the headline number for anyone cleaning a switching-regulator ripple off a 3.0 V analog rail; that rejection drops with frequency, but at 1 kHz it gives about a 1.8 mV ripple attenuation from a 1 Vpp input. The 70 µA quiescent current keeps the always-on budget tight for battery-powered or standby supplies. Enable and soft-start are on-chip, so you get controlled ramp-up without an external cap. Over-current, over-temperature, and UVLO protection are built in — no extra supervisor needed for basic fault coverage.
Dropout and input range — sizing the headroom
Maximum dropout is 0.27 V at the full 300 mA load. That means a 3.3 V input rail — common after a 5.0 V to 3.3 V buck — still holds regulation through a 300 mV dip. The maximum input is 5.5 V, so a 5.0 V ±10% rail is fine, but you cannot run it from a 12 V intermediate bus. For a 3.0 V output, the practical input floor is about 3.27 V at full current; below that you start dropping out. The 420 µA maximum supply current is the total drawn from the input, including the pass-element drive — useful for estimating total power dissipation in a sealed enclosure.
Temperature grade and where it fits
Rated for junction temperature from -40°C to 125°C, so this LDO suits industrial control cabinets, outdoor telecom gear, and under-hood automotive modules that see under-bonnet heat. The TSOT-23-5 package is small — about 2.9 mm × 2.8 mm — which helps on dense boards, but the lack of a thermal pad means the PCB copper area does the heat sinking. At 300 mA with a 1.0 V drop (3.3 V in, 3.0 V out), dissipation is 300 mW; in still air at 85°C ambient, that needs about 1 in² of 1 oz copper to keep the junction below 125°C. The ROHS3 compliance covers the current EU exemption set.
Lifecycle and sourcing reality
ADI lists the ADP1712AUJZ-3.0-R7 as Active — no last-time-buy notice, no NRND flag. If you need cut tape or smaller quantities, the same die in the same package is also offered as cut tape.