**ADP1707ARDZ-8-R7: A Comprehensive Technical Overview of the 200 mA, 8 V Low-Noise CMOS LDO Regulator**

In the realm of power management, the demand for clean, stable, and efficient voltage regulation is paramount, especially for noise-sensitive applications like RF transceivers, precision analog sensors, and high-fidelity audio equipment. The **ADP1707ARDZ-8-R7** from Analog Devices stands out as a exemplary solution, engineered to meet these critical demands. This article provides a detailed technical examination of this high-performance, low-dropout (LDO) linear regulator.

The ADP1707 is a **200 mA maximum output current** LDO regulator built on a CMOS process. The specific part number **ADP1707ARDZ-8-R7** denotes a fixed **8.0 V output voltage** version in a compact 4-lead LFCSP_WD package supplied on a 7-inch reel. Its primary defining characteristic is its exceptionally low noise performance, making it an ideal choice for powering the most sensitive circuit components.

**Key Technical Features and Performance**

* **Ultra-Low Output Noise:** A standout feature of the ADP1707 is its ability to generate an incredibly clean output voltage. It achieves **just 9 μV RMS of output noise** (integrated from 10 Hz to 100 kHz) without requiring an external bypass capacitor. This is crucial for preventing noise from the power supply from degrading the signal-to-noise ratio (SNR) in communication and measurement systems.

* **Excellent Power Supply Rejection (PSRR):** The regulator effectively attenuates ripple and noise coming from the input supply. It boasts a **high PSRR of 70 dB at 1 kHz**, which remains above 40 dB at 100 kHz. This ensures that fluctuations on the input rail, common in systems with switching regulators upstream, are prevented from reaching the sensitive load.

* **Low Dropout Voltage:** The CMOS architecture enables a **low dropout voltage of typically 110 mV at 200 mA load**. This allows the regulator to maintain regulation with a very small headroom between the input and output voltages, enhancing efficiency and enabling operation in low-input-voltage scenarios.

* **High Accuracy and Stability:** The device features a **tight output voltage accuracy of ±0.8%** over line, load, and temperature variations. It is stable with a small, space-saving 1.0 μF ceramic output capacitor, simplifying board design and reducing the overall bill of materials (BOM).

* **Robust Protection Features:** The ADP1707 incorporates comprehensive protection mechanisms, including **current limiting and thermal shutdown**, which safeguard the regulator and the downstream circuitry under fault conditions such as short circuits or excessive power dissipation.

**Typical Applications**

The combination of low noise, high PSRR, and low dropout makes the ADP1707ARDZ-8-R7 exceptionally suited for a wide range of applications:

* Powering **RF and Mixed-Signal Circuits** (PLLs, VCOs, ADCs, DACs)

* **Precision Analog Sensors** and Measurement Equipment

* **Medical Instrumentation** and Imaging Systems

* **Portable Battery-Powered Equipment** where clean power is essential

* **Post-Regulation** for switching power supplies (SMPS) to achieve a low-noise final output

**ICGOODFIND**

The **ADP1707ARDZ-8-R7** establishes itself as a superior component in the LDO market. Its **best-in-class low-noise performance and high PSRR** directly address the core challenges in designing advanced electronic systems. For engineers tasked with optimizing the performance of noise-sensitive subsystems, this regulator offers a reliable, high-accuracy, and robust solution that significantly contributes to achieving superior overall system performance.

**Keywords:**

1. **Low-Noise LDO Regulator**

2. **High PSRR**

3. **200 mA Output Current**

4. **CMOS Process**

5. **Thermal Shutdown Protection**