The **ADP172ACBZ-2.1-R7** is a low dropout (LDO) linear regulator designed by Analog Devices. It is specifically engineered for high-performance, space-constrained applications like smartphones, portable medical devices, and wireless sensor nodes. --- ### 1. Key Technical Specifications | Parameter | Specification | | :--- | :--- | | **Input Voltage Range** | 1.6 V to 3.6 V | | **Output Voltage** | 2.1 V (Fixed) | | **Maximum Output Current** | 300 mA | | **Dropout Voltage** | 50 mV (Typical at 300 mA load) | | **Quiescent Current** | 23 μA (Typical with no load) | | **Shutdown Current** | < 1 μA | | **PSRR (Power Supply Rejection Ratio)** | 70 dB at 10 kHz | | **Package Type** | 4-ball WLCSP (Wafer Level Chip Scale Package) | --- ### 2. Functional Features * **Low Dropout Voltage:** The device maintains regulation even when the input voltage is very close to the output voltage (only 50mV difference required at full load), which extends battery life. * **Enable/Shutdown Control:** It features an enable pin (`EN`). When pulled low, the device enters a shutdown mode, consuming less than 1 μA, which is critical for power-saving in mobile devices. * **Internal Protection:** * **Short-Circuit Protection:** Prevents damage during fault conditions. * **Thermal Overload Protection:** Automatically shuts down if the junction temperature exceeds safe limits. * **Stability:** Optimized for use with small, low-ESR ceramic capacitors (as small as 1 μF). --- ### 3. Pin Configuration (WLCSP) The device uses a 4-ball grid arrangement: | Ball | Symbol | Description | | :--- | :--- | :--- | | **A1** | **VIN** | Regulator Input Supply | | **A2** | **VOUT** | Regulated Output Voltage | | **B1** | **EN** | Enable Input (High = On, Low = Off) | | **B2** | **GND** | Ground | --- ### 4. Typical Application Circuit ```mermaid graph LR Vin[Input Voltage] --> C1[1uF Capacitor] C1 --> VIN_Pin[ADP172 VIN] EN_Pin[Enable Pin] --- Switch[Logic High/Low] VIN_Pin --> VOUT_Pin[ADP172 VOUT] VOUT_Pin --> C2[1uF Capacitor] C2 --> Load[System Load] GND_Pin[ADP172 GND] --- Ground[PCB Ground] ``` --- ### 5. Part Number Breakdown: `ADP172ACBZ-2.1-R7` * **ADP172**: Model series (300 mA LDO). * **A**: Operating temperature range (-40°C to +125°C). * **CBZ**: Package code (WLCSP - Halogen Free/RoHS Compliant). * **2.1**: Output voltage setting (2.1 Volts). * **R7**: Packaging format (7-inch Tape and Reel, typically 3,000 pieces).