USB Power Manager with Li-Ion Charger and Three Step-Down Regulators The LTC3557EUF#PBF is a highly integrated power management IC (PMIC) manufactured by **Linear Technology** (now part of Analog Devices). Below are its key specifications, descriptions, and features:
### **Specifications:**
- **Input Voltage Range:** 4.35V to 5.5V (USB-compatible)
- **Battery Charger:**
- **Charge Voltage:** 4.2V (adjustable)
- **Charge Current:** Up to 950mA (programmable)
- **Charge Termination:** C/10 or timer-based
- **Buck Regulators:**
- **Buck 1 (Main Buck):** 1.8V to 3.3V output, 400mA max
- **Buck 2 (Auxiliary Buck):** 0.8V to 5V output, 600mA max
- **LDO Regulator:**
- **Output Voltage:** 2.85V (fixed)
- **Output Current:** 50mA max
- **Operating Temperature Range:** -40°C to +85°C
- **Package:** 24-Lead QFN (4mm x 4mm)
### **Descriptions:**
The LTC3557EUF#PBF is a compact PMIC designed for portable applications, integrating a **Li-Ion/Polymer battery charger**, two **synchronous buck regulators**, and an **LDO regulator**. It supports USB and wall adapter inputs, providing efficient power management for systems like smartphones, tablets, and portable devices.
### **Features:**
- **USB-Compliant Charging:** Supports 100mA, 500mA, and high-current (950mA) modes.
- **Automatic Power Path Management:** Seamlessly switches between battery and input power.
- **Low Quiescent Current:** Extends battery life in portable applications.
- **Thermal Regulation:** Protects the IC during high-power operation.
- **I²C Control Interface:** Allows dynamic adjustment of output voltages and charger settings.
- **Battery Detection & Protection:** Includes undervoltage lockout (UVLO) and thermal shutdown.
This IC is optimized for space-constrained designs requiring efficient power conversion and battery charging.
*(Data sourced from Linear Technology/Analog Devices product documentation.)*
