**ADM7172ACPZ-0-R7: A Comprehensive Guide to the 5V, 2A Ultra-Low Noise LDO Voltage Regulator**

In the world of high-performance electronics, power integrity is paramount. Sensitive components like RF transceivers, high-speed data converters, and precision analog circuits demand a clean, stable, and noise-free supply voltage to function at their peak. This is where ultra-low noise, high-current Low-Dropout (LDO) regulators become critical. The **ADM7172ACPZ-0-R7** from Analog Devices stands out as a premier solution, engineered to meet the most demanding power supply requirements.

**What is the ADM7172ACPZ-0-R7?**

The ADM7172ACPZ-0-R7 is a specific model in the ADM7172 family of LDO voltage regulators. This variant is fixed to provide a **precise 5V output** from a higher input voltage source. It is capable of delivering a substantial **continuous output current of up to 2A** with a remarkably low dropout voltage of only 175 mV at full load. Housed in a compact, thermally efficient 6-lead LFCSP package (3mm x 3mm), it is designed for space-constrained applications. The "R7" designation indicates it is supplied on a 7-inch reel for volume manufacturing.

**Key Features and Technical Superiority**

The ADM7172 is packed with features that make it an exceptional choice for noise-sensitive applications:

* **Ultra-Low Output Noise:** This is its defining characteristic. The regulator achieves an incredibly low output noise of **4.5 μV rms** (typical) from 10 Hz to 100 kHz. This is accomplished through an innovative design that includes an integrated **silicon-based bypass capacitor**, significantly reducing noise without requiring large external capacitors.

* **Excellent Power Supply Rejection Ratio (PSRR):** The ADM7172 offers outstanding PSRR performance, exceeding **80 dB at 10 kHz** and remaining above 60 dB up to 1 MHz. This means it effectively rejects ripples and noise from the upstream power supply (e.g., a switching regulator), ensuring a clean output even from a noisy input source.

* **High Accuracy and Stability:** The output voltage is accurate to within ±1.5% over line, load, and temperature variations. It remains stable with small, space-saving ceramic output capacitors as low as 4.7 μF, simplifying board design and reducing the bill of materials.

* **Full Protection Suite:** The device is robust and protected against fault conditions. It includes internal current limiting and thermal shutdown features, safeguarding both the regulator and the load it powers from damage due to overcurrent or overtemperature events.

**Typical Applications**

The combination of high current, ultra-low noise, and high PSRR makes the ADM7172ACPZ-0-R7 ideal for a wide range of applications, including:

* Powering **FPGAs, ASICs, and DSPs** that require clean core and auxiliary voltages.

* Supplying low-noise bias to **RF amplifiers, mixers, and oscillators (VCOs)** in communication infrastructure.

* Providing clean power to **high-resolution ADCs and DACs** to prevent noise from degrading signal-to-noise ratio (SNR).

* Medical imaging and diagnostic equipment where signal integrity is non-negotiable.

* Test and measurement instrumentation requiring the highest precision.

**Design Considerations**

Implementing the ADM7172 is straightforward. For optimal performance, careful attention should be paid to:

* **Input and Output Capacitors:** While stable with small ceramics, using low-ESR capacitors on the input and output is crucial for stability and transient response. The datasheet provides specific recommendations.

* **Thermal Management:** Delivering 2A of current dissipates power as heat. The **P** in its package code (CPZ) signifies a thermally enhanced lead frame. Proper PCB layout with adequate thermal vias and copper pours is essential to maximize power dissipation and prevent thermal shutdown.

* **Dropout Voltage:** Ensure the input voltage always remains above the output voltage plus the dropout voltage (VOUT + VDO) under all load conditions, especially at the maximum 2A load.

**ICGOOODFIND**

The **ADM7172ACPZ-0-R7** is a benchmark in high-performance LDO regulation. It masterfully combines the critical trio of **high output current (2A), ultra-low noise, and exceptional PSRR** in a miniature package. For designers tackling the power challenges of advanced digital and analog systems, this regulator offers a reliable and superior solution to ensure ultimate system performance and integrity.

**Keywords:**

1. **Ultra-Low Noise LDO**

2. **2A Output Current**

3. **High PSRR**

4. **5V Voltage Regulator**

5. **Precision Analog Power**