**ADP7118AUJZ-5-R7: A Comprehensive Technical Overview and Application Guide**

The **ADP7118AUJZ-5-R7** from Analog Devices is a high-performance, low-noise, CMOS low-dropout (LDO) linear regulator designed to meet the stringent power requirements of modern analog and mixed-signal circuits. This device provides a fixed **5.0 V output** from an input voltage range of **2.7 V to 5.5 V**, delivering a maximum output current of 200 mA. Its exceptional performance characteristics make it an ideal choice for applications such as powering precision analog-to-digital converters (ADCs), digital-to-analog converters (DACs), sensors, and RF circuitry where clean, stable power is paramount.

A defining feature of the ADP7118 is its **ultra-low output noise performance of 9 μV√Hz**, which is crucial for noise-sensitive applications. This is complemented by an outstanding **power supply rejection ratio (PSRR)** of up to 72 dB at 10 kHz, enabling the LDO to effectively attenuate unwanted ripple and noise from upstream switching regulators or other noisy power sources. This combination ensures a pristine supply voltage, free from disturbances that could degrade the performance of sensitive components.

The device is built for stability and reliability, requiring only a small **1.0 μF ceramic output capacitor** for stable operation, which saves valuable board space. It incorporates key protection features including **current limiting and thermal shutdown**, safeguarding both the regulator and the load under fault conditions. The ADP7118AUJZ-5-R7 is offered in a compact **5-lead TSOT package**, making it suitable for space-constrained applications.

**Application Guide and Key Considerations**

For optimal performance, careful design and layout are essential:

1. **Input and Output Capacitors:** While the LDO is stable with just 1.0 μF ceramics, using larger values on the input can further improve transient response and PSRR. Always place these capacitors as close as possible to the device's pins.

2. **Thermal Management:** Although the dropout voltage is a low 175 mV (typical), power dissipation (P_DISS = (V_IN - V_OUT) * I_LOAD) must be calculated to ensure the junction temperature remains within limits. Proper PCB layout with thermal grounding is critical for high load currents.

3. **Noise-Critical Designs:** For the lowest possible noise, bypassing the `NR` (Noise Reduce) pin with a capacitor to ground is recommended. This capacitor forms a low-pass filter with an internal resistor, further reducing the integrated output noise.

4. **Load and Line Transients:** The ADP7118 offers excellent transient response. To enhance it further, ensure low-ESR capacitors are used and minimize parasitic inductance in the power traces.

**ICGOOODFIND:** The ADP7118AUJZ-5-R7 stands out as a premier solution for engineers seeking a **high-PSRR, low-noise LDO** in a miniature package. Its robust feature set and Analog Devices' proven reliability make it a superior choice for purifying power rails in the most demanding precision applications, from medical instrumentation to communications infrastructure.

**Keywords:** **Low-Dropout (LDO) Regulator**, **Ultra-Low Noise**, **High PSRR**, **Precision Analog Power**, **200mA Output Current**