Linear Li-Ion Battery Charger with Thermal Regulation in ThinSOT The LTC4057ES5-4.2#PBF is a linear battery charger IC manufactured by Linear Technology (now part of Analog Devices). Below are the factual specifications, descriptions, and features from Ic-phoenix technical data files:
### **Specifications:**
- **Manufacturer:** LINEAR (Linear Technology)
- **Part Number:** LTC4057ES5-4.2#PBF
- **Package:** SOT-23-5
- **Input Voltage Range:** 4.25V to 6.5V
- **Charge Voltage:** Fixed 4.2V (for single-cell Li-Ion/Polymer batteries)
- **Charge Current:** Programmable up to 500mA
- **Preconditioning Mode:** Yes (for deeply discharged batteries)
- **Charge Termination:** C/10 (10% of programmed current)
- **Automatic Recharge:** Yes (when battery voltage falls below 4.05V)
- **Thermal Regulation:** Yes (prevents overheating)
- **Operating Temperature Range:** -40°C to +85°C
### **Descriptions:**
- The LTC4057ES5-4.2#PBF is a standalone linear charger designed for single-cell lithium-ion/polymer batteries.
- It integrates a power MOSFET, current sensing, and reverse-blocking diode, eliminating the need for external components.
- The device operates from a USB port or an AC adapter and includes thermal regulation to optimize charging under high-power conditions.
### **Features:**
- **Complete Charger:** No external MOSFET or blocking diode required.
- **Programmable Charge Current:** Up to 500mA via an external resistor.
- **Preconditioning for Deeply Discharged Cells:** Automatically reduces charge current for safe recovery.
- **Automatic Recharge:** Ensures the battery remains fully charged.
- **Thermal Regulation:** Protects the IC from overheating.
- **Charge Status Output:** Open-drain indicator pin (CHRG) for monitoring charge cycle.
- **Battery Detection:** Ensures no battery is present before applying power.
- **Reverse-Blocking Protection:** Prevents battery discharge when input power is removed.
This information is strictly based on the manufacturer's datasheet and knowledge base.
