The **ADP2291ACPZ-R7** is a high-performance, compact, constant-current/constant-voltage (CC/CV) linear charger designed specifically for single-cell Lithium-Ion (Li-Ion) batteries. It is manufactured by Analog Devices. --- ### 1. General Specifications Below are the primary technical parameters for the component: | Parameter | Specification | | :--- | :--- | | **Function** | Linear Battery Charger | | **Battery Chemistry** | Single-cell Lithium-Ion / Lithium-Polymer | | **Input Voltage Range** | 4.5 V to 12 V | | **Max Charge Current** | 1.5 A (Adjustable) | | **Package** | 8-Lead LFCSP (3mm x 3mm) | | **Operating Temp** | -40°C to +125°C | --- ### 2. Key Electronic Features The ADP2291 incorporates several specialized internal circuits to manage battery health and safety: * **Charging Phases:** It manages the three critical stages of Li-Ion charging: 1. **Trickle Charge:** For deeply discharged batteries. 2. **Constant Current (CC):** Rapid charging up to 1.5A. 3. **Constant Voltage (CV):** Final topping-off phase with 1% voltage accuracy. * **Thermal Regulation:** The chip features an internal thermal feedback loop that limits the charge current if the die temperature exceeds a specific threshold, preventing the PCB from overheating. * **Programmable Current:** The charge current is set using an external resistor, allowing designers to customize the speed for different battery capacities. * **Safety Timers:** Includes an integrated end-of-charge timer to prevent indefinite charging of faulty cells. --- ### 3. Pinout Functions (8-Lead LFCSP) The following table describes the primary pins used in the circuit design: | Pin Name | Description | | :--- | :--- | | **VIN** | Input Supply Voltage. | | **VOUT** | Output to the battery; provides charge current. | | **ISET** | Charge current program point (connect resistor to GND). | | **CHG** | Open-drain status output (indicates charging/done). | | **EN** | Enable input; pulls low to shut down the IC. | | **GND** | Ground and thermal pad connection. | --- ### 4. Typical Application Circuit To use the ADP2291, a minimal number of external components is required: ```c /* Basic Connection Logic */ [Power Source (5V)] ---> VIN Pin [VOUT Pin] ---> [+] Battery Terminal [ISET Pin] ---> [Resistor R_set] ---> GND [CHG Pin] ---> [LED + Resistor] ---> VIN (Status indicator) ``` ### 5. Part Number Suffix Meaning * **ADP2291:** Model Number. * **ACPZ:** Lead-free (RoHS compliant) LFCSP package. * **R7:** Denotes 7-inch tape and reel packaging (typically 1,500 units). ---