Product Overview
The ADP124ARHZ-3.3-R7 from Analog Devices is a 3.3V fixed-output LDO regulator delivering 500 mA with only 280 mV dropout and 25 µA quiescent current. The 70 dB PSRR makes it ideal for noise-sensitive RF and analog power rails in portable and battery-powered systems.
Key Specifications
| Function | 3.3V fixed, 500mA LDO |
| Output Voltage | 3.3V fixed |
| Output Current | 500 mA |
| Dropout Voltage | 280 mV at 500 mA |
| PSRR | 70 dB at 1 kHz |
| Quiescent Current | 25 µA |
| Package | MSOP-8 (3x3mm) |
Working Principle
PMOS pass transistor provides low dropout. Internal bandgap reference (1.2V) is divided to set 3.3V output. Error amplifier drives pass gate to maintain regulation under load and line transients. Current limit (800 mA typ) and thermal shutdown protect the device. Ultra-low 25 µA IQ maximizes battery life.
Applications
- RF transceiver LNA/PA power
- Portable instrument analog rail
- Battery-powered MCU supply
- Post-regulation from DC-DC