**ADP7142AUJZ-0-R7: A Comprehensive Guide to the 0V, 200mA Low-Noise LDO Regulator**

In the world of precision electronics, where clean and stable power is non-negotiable, Low-Dropout (LDO) regulators are indispensable components. Among them, the **ADP7142AUJZ-0-R7** stands out as a premier solution for applications demanding ultra-low noise and high power supply rejection. This article provides a deep dive into its features, operation, and ideal use cases.

The ADP7142 is a high-performance, low-noise CMOS LDO linear regulator from Analog Devices. The specific part number `ADP7142AUJZ-0-R7` denotes a device with a fixed **0V output voltage** and a capable **200mA output current**. This 0V output version is uniquely designed to serve as a high-performance negative voltage regulator or an active load for sinking current, a feature that sets it apart from standard positive LDOs.

**Key Features and Advantages**

* **Ultra-Low Noise Performance:** The ADP7142 excels in its primary function of noise suppression. It achieves an impressively low output noise of **just 5.8 µV√Hz (typ) at 10 kHz**. This is crucial for powering sensitive analog circuitry like RF transceivers, precision sensors, and high-fidelity audio components, where noise can severely degrade signal integrity.

* **Excellent Power Supply Rejection (PSRR):** The regulator effectively filters out ripple and noise originating from the input power source. It boasts a high PSRR of **70 dB at 10 kHz**, ensuring that disturbances on the input line do not appear on the regulated output. This is particularly valuable in mixed-signal systems where noisy digital circuits share a power bus with analog components.

* **Low Dropout Voltage:** With a typical dropout voltage of only **120 mV at 200 mA load**, the ADP7142 can maintain regulation even when the input voltage is very close to the output voltage. This enhances efficiency and allows operation in low-input-voltage scenarios, extending battery life in portable devices.

* **Wide Input Voltage Range:** The device supports an input voltage range from **2.3 V to 20 V**, offering significant design flexibility for a variety of power rails, including 3.3V, 5V, 12V, and higher.

* **Compact Package:** Housed in a tiny **5-Lead TSOT** package, the ADP7142AUJZ-0-R7 is ideal for space-constrained PCB designs common in modern portable and compact electronics.

**Application Circuits and Usage**

The `-0-R7` variant's ability to sink current makes it exceptionally versatile. A common application is generating a clean, negative bias voltage. For instance, it can be configured to regulate a positive input voltage (e.g., +3.3V) down to a precise negative output (e.g., -3.0V). This is invaluable for biasing components like GaAs amplifiers, op-amps, and data converters that require a negative supply rail.

Furthermore, its current-sinking capability allows it to be used as an active load, providing a stable, low-noise path to ground for other parts of a circuit, which can be essential for testing and precision current management.

**Design Considerations**

While implementing the ADP7142, careful attention must be paid to external component selection. **Stable operation requires specific output capacitance**; Analog Devices recommends a 2.2 µF ceramic capacitor on the output for stability. Proper PCB layout is also critical—placing the input and output capacitors as close as possible to the regulator's pins is essential to minimize parasitic inductance and realize the full benefits of its high PSRR and low-noise performance.

**ICGOODFIND**: The ADP7142AUJZ-0-R7 is a superior choice for engineers designing systems where pristine power quality is paramount. Its combination of **ultra-low noise, excellent PSRR, and unique current-sinking functionality** makes it an indispensable component for powering sensitive analog and RF circuits, generating negative voltage rails, and ensuring signal integrity in the most demanding applications.

**Keywords**:

1. **Low-Noise LDO Regulator**

2. **Negative Voltage Regulation**

3. **Power Supply Rejection Ratio (PSRR)**

4. **Current Sink**

5. **Precision Analog Power**