**ADM7155ARDZ-04-R7: A 0V, 500mA Ultralow Noise, High PSRR RF Linear Regulator**

In the demanding world of RF and precision analog circuitry, power integrity is paramount. Noise, ripple, and instability from the power supply can severely degrade the performance of sensitive components like LNAs, PLLs, VCOs, and high-resolution ADCs/DACs. Addressing these critical challenges head-on, the **ADM7155ARDZ-04-R7** from Analog Devices emerges as a premier solution, engineered to deliver pristine, stable power.

This advanced linear regulator is distinguished by its **ultralow output noise of just 4 μV√Hz** at a fixed 4.0V output. This exceptional characteristic is crucial for minimizing phase noise in oscillators and clocking circuits, thereby improving overall signal integrity and system signal-to-noise ratio (SNR). Furthermore, the device boasts an outstanding **power supply rejection ratio (PSRR) of 70 dB at 10 kHz**, effectively filtering out high-frequency noise and ripple originating from upstream switching regulators or other noisy power sources. This high PSRR ensures that the regulator's output remains clean and undisturbed even when the input voltage is not.

The ADM7155ARDZ-04-R7 provides a substantial **output current capability of up to 500mA**, making it suitable for powering multiple blocks or more power-hungry RF ICs. Its **wide input voltage range of 3.3V to 5.5V** allows for flexibility in system design, accommodating common power bus voltages. A key feature for safety-critical and precision applications is its **0V start-up capability**, which guarantees a known, controlled state upon power application.

Housed in a compact, space-saving 8-lead SOIC package, this regulator integrates all necessary features, including a soft-start function to limit inrush current and built-in protection circuits for overcurrent and thermal overload conditions. Its combination of ultra-low noise, high PSRR, and robust current delivery makes it an indispensable component for achieving the highest levels of performance in test and measurement equipment, medical imaging systems, wireless infrastructure, and satellite communications.

**ICGOOFind: The ADM7155ARDZ-04-R7 is an elite ultra-low noise linear regulator that sets the benchmark for powering noise-sensitive RF and analog applications. Its best-in-class combination of 4 μV√Hz noise, 70 dB PSRR, and 500mA output current in a small form factor provides designers with a critical tool for maximizing system performance and reliability.**

**Keywords:** Ultralow Noise, High PSRR, RF Linear Regulator, 500mA, Power Supply Rejection Ratio