The **ADP7118ARDZ-3.3-R7** is a high-performance, low dropout (LDO) linear regulator manufactured by Analog Devices. It is designed to provide a clean, stable voltage supply for noise-sensitive analog and mixed-signal circuits. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Input Voltage Range** | 2.7 V to 20 V | | **Output Voltage (Fixed)** | 3.3 V | | **Maximum Output Current** | 200 mA | | **Dropout Voltage** | 200 mV (typical at 200 mA) | | **PSRR (Power Supply Rejection Ratio)** | 88 dB at 10 kHz; 40 dB at 1 MHz | | **Output Noise** | 11 μV rms (independent of output voltage) | | **Operating Temperature** | -40°C to +125°C | | **Package Type** | 8-Lead SOIC_N_EP (Exposed Pad) | --- ### 2. Electronic Characteristics & Features #### A. High PSRR and Low Noise The most significant feature of the ADP7118 is its ability to filter out input noise. With a PSRR of 88 dB at lower frequencies, it is ideal for powering sensitive components like ADCs, DACs, and precision amplifiers where power supply ripples can degrade performance. #### B. Wide Input Voltage Range Unlike many LDOs that operate only up to 5V or 6V, the ADP7118 supports up to 20V. This makes it versatile for industrial applications where a 12V or 15V rail needs to be stepped down to 3.3V. #### C. Precision Enable and Soft Start The device includes a precision enable input. This allows the designer to set a specific threshold for when the regulator turns on. It also features internal circuitry to limit inrush current during startup. #### D. Protection Circuitry * **Thermal Overload Protection:** Shuts down the device if the junction temperature exceeds safety limits. * **Short-Circuit Protection:** Prevents damage if the output is accidentally grounded. * **Reverse Current Protection:** Protects the device if the output voltage becomes higher than the input voltage. --- ### 3. Application Use Cases 1. **ADC/DAC Powering:** Providing ultra-quiet power to prevent jitter and noise in signal conversion. 2. **RF Communications:** Powering low-noise amplifiers (LNAs) and frequency synthesizers. 3. **Medical Instrumentation:** Used in precision measurement devices requiring high stability. 4. **Industrial Automation:** Handling high-voltage rails while providing a regulated low-voltage output for microcontrollers. --- ### 4. Implementation Example When designing a PCB with this part, it is recommended to use small ceramic capacitors for stability. ```markdown Recommended Capacitors: - Input Capacitor (Cin): 2.2 μF (X5R or X7R) - Output Capacitor (Cout): 2.2 μF (Low ESR is critical for stability) ```