The **ADP191ACBZ-R7** is a high-side load switch designed by Analog Devices. It is specifically engineered to control power rails in portable electronics, providing a way to turn on or off specific subsystems to conserve battery life. --- ## 1. Core Technical Specifications The following table summarizes the primary electrical characteristics of the ADP191ACBZ-R7: | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 1.1 V to 3.6 V | | **Continuous Current** | Up to 500 mA | | **On-Resistance ($R_{ON}$)** | 80 mΩ (at 1.8 V) | | **Quiescent Current** | 2 µA (Typical) | | **Shutdown Current** | < 1 µA | | **Package Type** | 4-ball WLCSP (0.8 mm x 0.8 mm) | --- ## 2. Key Internal Components & Features ### A. P-Channel MOSFET The heart of the device is a low resistance **P-channel MOSFET**. Unlike N-channel switches that often require a charge pump, this P-channel design allows for a low-dropout voltage and simple control logic. ### B. Logic Level Control (EN Pin) The device includes an **Enable (EN)** pin. * **High Logic:** Turns the switch ON. * **Low Logic:** Turns the switch OFF. * The logic levels are compatible with standard microcontrollers and GPIOs (1.2 V to 3.3 V logic). ### C. Integrated Level Shifter It features an internal level shifter that allows the EN pin to be controlled by a low-voltage GPIO, even if the input voltage ($V_{IN}$) is higher. --- ## 3. Application Use Cases The ADP191 is commonly used in space-constrained, battery-operated devices: 1. **Mobile Devices:** Turning off GPS, Wi-Fi, or Camera modules when not in use. 2. **Wearables:** Managing power for heart rate sensors or displays. 3. **Power Sequencing:** Ensuring specific peripheral chips power up only after the main processor is stable. --- ## 4. Typical Application Circuit ```mermaid graph LR Vin[Input Power 1.1V-3.6V] --> ADP191 Enable[GPIO Control] --> ADP191 GND[Ground] --- ADP191 ADP191 --> Vout[Regulated Output to Load] ``` ### Pin Configuration (4-Ball WLCSP) * **A1:** $V_{IN}$ (Input Voltage) * **A2:** $V_{OUT}$ (Output Voltage) * **B1:** EN (Enable Input) * **B2:** GND (Ground) ---