## Overview of ADP124ACPZ-1.8-R7 The **ADP124ACPZ-1.8-R7** is a low quiescent current, low dropout (LDO) linear regulator manufactured by Analog Devices. It is designed to provide a stable, fixed output voltage of **1.8V** from an input voltage range, making it ideal for battery-powered and space-constrained applications. --- ### Key Specifications Below are the primary technical characteristics of the component: | Parameter | Specification | | :--- | :--- | | **Output Voltage** | 1.8V (Fixed) | | **Input Voltage Range** | 2.3V to 5.5V | | **Maximum Output Current** | 500 mA | | **Dropout Voltage** | 130 mV @ 500 mA | | **Quiescent Current ($I_q$)** | 7 µA (at no load) | | **Shutdown Current** | < 1 µA | | **Package** | 8-Lead LFCSP (2mm x 2mm) | | **Operating Temperature** | -40°C to +125°C | --- ### Key Features and Internal Components 1. **Low Dropout (LDO) Architecture:** The device uses a PMOS pass element, which allows for a very low dropout voltage. This ensures the regulator can maintain a 1.8V output even when the input battery voltage drops very close to the output target. 2. **Internal Protection Circuitry:** * **Thermal Overload Protection:** Automatically shuts down the device if the junction temperature exceeds safe limits. * **Short-Circuit Protection:** Includes current limiting to prevent damage during fault conditions. 3. **Enable Pin (EN):** Allows the device to be turned on or off via logic signals. When disabled, it draws less than 1 µA, preserving battery life. 4. **Stability:** It is specifically designed for stable operation with small **1 µF ceramic input and output capacitors**, reducing the overall PCB footprint. --- ### Pin Configuration (LFCSP Package) | Pin No. | Name | Description | | :--- | :--- | :--- | | 1 | **VIN** | Regulator Input Supply | | 2, 3 | **NC** | No Connection | | 4 | **EN** | Enable Input (High = On, Low = Off) | | 5 | **GND** | Ground | | 6 | **NC** | No Connection | | 7 | **VOUT** | Regulated Output Voltage (1.8V) | | 8 | **NC** | No Connection | | EP | **Exposed Pad** | Should be connected to Ground for thermal dissipation | --- ### Typical Application Circuit ```mermaid graph LR Vin[Input 2.3V-5.5V] -->|C1: 1uF| IC(ADP124) IC -->|C2: 1uF| Vout[Output 1.8V] EnablePin[Logic Signal] --> IC IC --- GND[Ground] ``` ### Common Use Cases * **Mobile Phones:** Powering digital cores and I/O. * **Digital Cameras:** Stable voltage for sensors. * **Portable Medical Devices:** High efficiency and low noise requirement. * **Post-Regulation:** Cleaning up noise from switching power supplies. ---