120 mA LDO with 78 dB PSRR — filtering upstream switcher noise
The MAX8510EXK45-T from Analog Devices is a single-output positive LDO regulator delivering 120 mA at a fixed 4.5 V. Its PSRR of 78 dB at 1 kHz dropping to 54 dB at 100 kHz means it attenuates switching ripple from a preceding buck converter by a factor of several thousand at the fundamental — useful when a clean analog rail is needed from a noisy intermediate bus. Quiescent current is 90 µA — not the lowest for battery-idle designs, but acceptable for always-on industrial sensor nodes where the LDO is fed from a 5 V or 6 V rail.
SC-70-5 footprint and board integration
Housed in a 5-lead SC-70-5 (SOT-353) package, this LDO occupies roughly 2.0 × 2.1 mm of board area — small enough to fit near the load in a space-constrained sensor module or interface circuit. The exposed die attach pad on the bottom is the thermal path; a via cluster under the pad to the ground plane keeps the junction temperature in check at 120 mA continuous. The shutdown control pin (active-low) lets a GPIO or supervisor pull the output to zero and cut the 90 µA quiescent draw. Over-current and over-temperature protection are built in — the regulator folds back current during a short and shuts down if the die exceeds the thermal limit, then auto-recovers when the fault clears.
Active lifecycle and compliance note
No pin-compatible second-source or official successor is recorded for this exact fixed-voltage variant.