**ADP7142ARDZ: A Comprehensive Technical Overview of the Low-Noise, High-PSRR LDO Voltage Regulator**

In the realm of power management for sensitive analog and RF circuits, the performance of the voltage regulator is paramount. The **ADP7142ARDZ from Analog Devices** stands out as a high-performance, low-dropout (LDO) linear regulator engineered specifically to meet the stringent requirements of noise-sensitive applications. This article provides a detailed technical examination of its architecture, key features, and typical use cases.

The ADP7142ARDZ is a negative-voltage LDO regulator capable of delivering a fixed or adjustable output voltage from -1.9 V to -5.5 V with a maximum output current of **200 mA**. Its core value proposition lies in its exceptional ability to provide a clean, stable output voltage from a noisy input supply. This is achieved through two defining characteristics: **ultra-low noise and high power supply rejection ratio (PSRR)**.

A critical feature of the ADP7142ARDZ is its impressively **low output noise of 9 μV√Hz** (integrated from 100 Hz to 100 kHz). This ultra-low noise floor is crucial for powering components like voltage-controlled oscillators (VCOs), phase-locked loops (PLLs), analog-to-digital converters (ADCs), and high-fidelity audio circuits, where any supply-borne noise can directly degrade signal integrity and overall system performance.

Complementing its low-noise performance is an outstanding **high PSRR of up to 75 dB at 10 kHz**. The PSRR metric quantifies the regulator's ability to reject ripple and noise originating from the input power supply. A high PSRR ensures that fluctuations on the input rail, common in systems with switching regulators upstream, are attenuated before they reach the sensitive load. This makes the ADP7142ARDZ an ideal choice as a point-of-load regulator following a noisy switching converter, effectively cleaning the power rail.

The device requires only a small **1.0 μF ceramic output capacitor** for stability, which minimizes the solution footprint and bill-of-materials cost. Its **low dropout voltage of 190 mV** (at 200 mA load) enhances power efficiency by allowing operation with a smaller voltage differential between the input and output. Furthermore, the ADP7142ARDZ incorporates essential protection features such as **current limiting and thermal shutdown**, safeguarding both the regulator and the load under fault conditions. It is offered in a compact 8-lead SOIC package, suitable for space-constrained PCB designs.

Typical applications span a wide range of industries and products, including:

* **Communication Infrastructure:** Powering low-noise amplifiers and RF transceivers.

* **Medical Instrumentation:** Supplying clean power to sensitive sensors and measurement front-ends.

* **Test and Measurement Equipment:** Ensuring accuracy in high-precision data acquisition systems.

* **Industrial and Automotive Systems:** Providing stable voltage references for control systems.

**ICGOOODFIND:** The ADP7142ARDZ is a premier solution for designers seeking to eliminate power supply noise in critical negative-voltage rails. Its best-in-class combination of **ultra-low noise and high PSRR** makes it an indispensable component for maximizing the performance of noise-sensitive analog and RF subsystems, ensuring superior signal clarity and system accuracy.

**Keywords: Low-Dropout (LDO) Regulator, Ultra-Low Noise, High Power Supply Rejection Ratio (PSRR), Negative-Voltage Regulator, RF/Analog Power Management**