## Overview of the ADP7183ACPZN3.3-R7 The **ADP7183ACPZN3.3-R7** is a high-performance, low-noise, CMOS linear regulator (LDO) designed by Analog Devices. It is specifically engineered to operate from a negative input voltage, providing a stable, regulated negative output voltage. --- ### Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | -2.0 V to -5.5 V | | **Fixed Output Voltage** | -3.3 V | | **Maximum Output Current** | 300 mA | | **PSRR (Power Supply Rejection Ratio)** | 75 dB at 10 kHz; 62 dB at 1 MHz | | **Low Noise** | 4 μV rms (100 Hz to 100 kHz) | | **Dropout Voltage** | 130 mV (at 300 mA load) | | **Operating Temperature** | -40°C to +125°C | | **Package** | 8-lead LFCSP (2 mm × 2 mm) | --- ### Core Electronic Features #### 1. Low Noise and High PSRR This LDO is optimized for noise-sensitive applications. The high PSRR allows it to filter out ripples from switching power supplies, making it ideal for powering sensitive analog circuits like ADCs, DACs, and precision amplifiers. #### 2. Negative Voltage Regulation Unlike standard LDOs that handle positive voltages, the ADP7183 is a **negative voltage regulator**. It is used in bipolar power supply rails (e.g., ±5V systems) to provide the negative 3.3V rail. #### 3. Precision Enable and Power Good - **Enable (EN) Pin:** Allows for digital control to turn the regulator on or off. - **Power Good (PG):** An open-drain output that goes high when the output voltage is within 90% of its nominal value, useful for power sequencing. #### 4. Protection Circuitry The device includes internal protection features to ensure longevity and reliability: * **Current-Limit Protection:** Prevents damage during overcurrent conditions. * **Thermal Shutdown (TSD):** Shuts down the device if the junction temperature exceeds safe limits. --- ### Typical Application Circuit To operate the ADP7183, minimal external components are required. Small ceramic capacitors are recommended for stability. ```markdown Vin (Negative) ----[ Cin: 2.2uF ]----| ADP7183 |----[ Cout: 2.2uF ]---- Vout (-3.3V) | GND | ``` --- ### Common Applications * **Regulation to noise-sensitive applications:** ADC and DAC circuits, precision amplifiers. * **Communications and Infrastructure:** Base stations and optical modules. * **Medical and Instrumentation:** High-speed data acquisition systems.