Texas Instruments bq25155 Battery Charge Management IC

The device supports a charge current of up to 500mA and a termination current down to 0.5mA for maximum charge. The battery is charged using a standard Li-Ion charge profile with three phases: pre-charge, constant current, and constant voltage regulation.

The Texas Instruments bq25155 integrates advanced power path management and control, allowing the device to power the system while charging the battery, even with poor adapters. The host may also control the power path through I²C, allowing it to disconnect the input adapter and/or battery without physically removing them. The single push-button input eliminates the need for a separate button controller IC, reducing the total solution footprint. The push-button input can be used for wake functions or to reset the system.

A 16-bit ADC enables accurate battery voltage monitoring and can be used to enable low I_q gauging to monitor battery health. It can also be used to measure the battery temperature using a thermistor connected to the TS pin and external system signals through a pin. The low quiescent current during operation and shutdown enables maximum battery life. The input current limit, charge current, LDO output voltage, and other parameters are programmable through the I²C interface, making the bq25155 a very flexible charging solution.

A voltage-based JEITA compatible (or standard HOT/COLD) battery pack thermistor monitoring input (TS) is included that monitors battery temperature. This battery pack automatically changes charge parameters to prevent the battery from charging outside its safe temperature range. The temperature thresholds are also programmable through I²C, allowing the host to customize the thermal charging profile. The charger is optimized for 5V USB input, with 20V absolute maximum tolerance to withstand line transients. The device also integrates a linear regulator to provide a quiet rail for radios or processors and can be independently sourced and controlled through I²C.