The SGM4056-6.8YTDE8G is a fully integrated single-cell Li-Ion/Li-Polymer linear charger IC manufactured by SG Micro Corp. It's designed to efficiently and safely charge single-cell lithium-ion or lithium-polymer batteries from a USB power source or an AC adapter. The IC incorporates features such as pre-charge conditioning, constant current charging, constant voltage charging, and charge termination. The 6.8 in the part number refers to the Input Overvoltage Protection threshold. This device is designed for portable applications, wearable devices, and other battery-powered systems.

Applications

• Wearable devices (smartwatches, fitness trackers)
• Portable media players (MP3 players, portable gaming consoles)
• Low-power handheld devices
• Bluetooth headsets and speakers
• IoT devices

Features

• Integrated pass transistor: Reduces external component count.
• Programmable charge current: Allows optimization for different battery capacities.
• Pre-charge conditioning: Safely charges deeply discharged batteries.
• Constant current/constant voltage (CC/CV) charging: Ensures optimal charging profile.
• Charge termination: Prevents overcharging and battery damage.
• Thermal protection: Limits the die temperature to prevent overheating.
• Input Overvoltage Protection: Protects the charger from damage due to excessive input voltage.
• Automatic recharge: Automatically restarts charging when the battery voltage drops below a certain threshold.

Benefits

• Simplified design: Integrated features reduce the need for external components.
• Optimal charging performance: CC/CV charging ensures efficient and safe battery charging.
• Enhanced battery life: Charge termination and thermal protection prevent overcharging and overheating, extending battery life.
• Improved safety: Thermal protection safeguards the device and battery from damage.
• Compact solution: Small package size is ideal for portable applications.

Additional Details

The SGM4056-6.8YTDE8G operates by regulating the charging current and voltage to the battery based on its state of charge. During pre-charge conditioning, a small current is applied to deeply discharged batteries to safely raise their voltage. Once the battery voltage reaches a certain threshold, the charger switches to constant current mode, delivering a fixed current to the battery until it reaches its target voltage (typically 4.2V). Then, the charger switches to constant voltage mode, maintaining the voltage while the charging current gradually decreases until it reaches the termination threshold. The IC also features thermal protection, which reduces the charging current if the die temperature exceeds a certain limit. The input overvoltage protection threshold is 6.8V. Typical package is TDFN-2x2-8L. It's designed to operate within a specified temperature range, typically -40°C to +85°C.