**ADP151ACBZ-0-R7: A Comprehensive Technical Overview of the 0V, 200mA Ultralow Noise LDO Regulator**

In the realm of power management, achieving clean, stable, and precise voltage regulation is paramount for the performance of sensitive analog and RF circuits. The **ADP151ACBZ-0-R7** from Analog Devices stands out as a premier solution, engineered to deliver exceptional performance in a miniature footprint. This article provides a detailed technical examination of this advanced linear regulator.

The ADP151 is a high-performance, **ultralow noise (0.8μVrms typical) CMOS low-dropout (LDO) linear regulator** capable of supplying up to 200 mA of output current. The specific part number **ADP151ACBZ-0-R7** denotes a device with a fixed 0V output voltage. This unique feature is designed specifically for **use as a high-performance shunt regulator or a low-noise bias supply** for components like GaAs FETs, where a negative gate bias (e.g., -3 V) is required. By grounding the VOUT pin and using the VIN pin as the output, the ADP151 can efficiently sink current, providing a stable, low-noise reference point.

A defining characteristic of the ADP151 is its **exceptional noise performance**. It integrates a proprietary internal band gap reference architecture that minimizes inherent noise. Furthermore, it includes a dedicated **noise reduction (NR) pin**. Connecting a small external capacitor (typically 10 nF) to this pin effectively bypasses the internal reference, reducing the output noise to the remarkably low level of **0.8 μVrms** (integrated from 10 Hz to 100 kHz). This makes it ideal for powering noise-sensitive components such as **RF transceivers, precision ADCs/DACs, oscillators, and sensors**.

Despite its tiny 0.5 mm x 0.4 mm WLCSP package, the regulator delivers outstanding power supply rejection (PSRR). It maintains **over 70 dB of PSRR at 1 kHz and greater than 40 dB at 100 kHz**, effectively filtering out high-frequency ripple and noise from upstream switching regulators or other noisy power sources. This high PSRR ensures a clean output even when the input supply is significantly contaminated.

The device operates with a very low dropout voltage of **typically 110 mV at 200 mA load**, enhancing power efficiency and allowing operation with lower input voltages. It also features a low quiescent current of 725 μA (typical) at full load, which helps in prolonging battery life in portable applications. Comprehensive internal protection circuits, including **current limiting and thermal shutdown**, ensure robust and reliable operation under fault conditions.

**ICGOOODFIND**: The ADP151ACBZ-0-R7 is not a standard LDO but a highly specialized component that excels in niche applications requiring ultralow noise and precise current sinking. Its unparalleled noise performance, high PSRR, and unique 0V output capability make it an indispensable solution for advanced RF and analog systems where power integrity is non-negotiable.

**Keywords**:

Ultralow Noise LDO

High PSRR

Shunt Regulator

RF Power Management

Current Sink