SC8753
High Efficiency Buck-Boost Converter with CC/CV and UART
Mode for TWS Charging Case Application
SC8753 is a dedicated buck-boost converter for TWS (True-wireless-stereo) charging case. The device can pair up with South Chip’s linear charger SC7289 and operate in charging mode or UART communication mode through 2-wire power contacts. For lithium batteries, the charging phase includes trickle charging, CC charging, and CV charging. During the trickle and CV charging phase, the charging parameter is controlled by the SC7289 in the earbud. During the CC charging phase, the SC7289 is fully on, and the SC8753 controls the charging current in constant current mode and supports up to 750mA continuous charging current with ultra-low thermal dissipation and high charging safety. In communication mode, the charging is suspended and the 2-wire power connection switches to a UART data connection. With bi-direction UART communication through the power line, the charging case and earbuds can swap data and request fast charging. The device integrates a synchronous 4-switch buck-boost converter with low quiescent current and PFM mode operation at light load. It provides excellent power efficiency, current, and voltage regulation no matter the charging voltage is higher, lower, or equal to the input voltage. It can support input voltage range from 2.7V to 5.5V and output voltage range from 3.0V to 5.2V. The device features an I2C interface, so the user can easily control the UART handshaking, program the charging current, charging voltage, and read changing/communication status through I2C. The IC also integrates an OD pin to speed up the switching process from charging mode to UART mode. The SC8753 employs peak current-mode control and supports cycle-by-cycle current limit, input under-voltage protection, output short protection, and over-temperature protection to ensure safety under different abnormal conditions.
SC8753 is a dedicated buck-boost converter for TWS (True-wireless-stereo) charging case. The device can pair up with South Chip’s linear charger SC7289 and operate in charging mode or UART communication mode through 2-wire power contacts. For lithium batteries, the charging phase includes trickle charging, CC charging, and CV charging. During the trickle and CV charging phase, the charging parameter is controlled by the SC7289 in the earbud. During the CC charging phase, the SC7289 is fully on, and the SC8753 controls the charging current in constant current mode and supports up to 750mA continuous charging current with ultra-low thermal dissipation and high charging safety. In communication mode, the charging is suspended and the 2-wire power connection switches to a UART data connection. With bi-direction UART communication through the power line, the charging case and earbuds can swap data and request fast charging. The device integrates a synchronous 4-switch buck-boost converter with low quiescent current and PFM mode operation at light load. It provides excellent power efficiency, current, and voltage regulation no matter the charging voltage is higher, lower, or equal to the input voltage. It can support input voltage range from 2.7V to 5.5V and output voltage range from 3.0V to 5.2V. The device features an I2C interface, so the user can easily control the UART handshaking, program the charging current, charging voltage, and read changing/communication status through I2C. The IC also integrates an OD pin to speed up the switching process from charging mode to UART mode. The SC8753 employs peak current-mode control and supports cycle-by-cycle current limit, input under-voltage protection, output short protection, and over-temperature protection to ensure safety under different abnormal conditions.
