True wireless stereo TWS headset charging base

System block diagram

    The PMIC used in the scheme is the configurable single-chip power management IC da9168 under Renesas. Its integrated dual LDO and reverse boost function can support the USB on the go (USB-OTG) standard. In addition, the PMIC chip achieves extremely low quiescent current consumption in a very compact volume, which makes it very suitable for many space oriented and battery powered consumer applications. Not only that, thanks to the various power saving modes of da9168, the battery life of the product can be extended whether it is stored idle or in operation. In terms of power supply design, the scheme can supply power to the PMIC through a USB connector or a single-chip 5W wireless power receiver (p9222-r). The power supply path is automatically selected by the 2:1 power multiplexer (slg591401c).

    In order to supplement the basic function set of any TWS charger base, a small 16 bit MCU with USB bc1.2 interface rl78 / g1c is added in the scheme to obtain the best charging support from any available USB type power supply. In addition, with the help of this MCU, the scheme can also support more advanced settings, such as power adjustment to optimize the charging speed of each audio device, and display the charging state and the remaining battery capacity (SOC) through a customized UI.

    For advanced charging algorithms, such as the design of direct charging of connected earphones, the solution integrates an slg46108 greenpak ™ The programmable mixed signal matrix serves as a PLC modulator / demodulator interface unit connected to the power supply to add a power line communication interface compatible with UART. This design enables each earphone to control its charging voltage and current without large-scale integrated power control, thus saving the number of pins between the base and the earphone and reducing PCB area and cost.

    In addition to the above advantages, the scheme also integrates the low-power Bluetooth chip da14683 into the system, which can realize device tracking, SOC information collection without inserting headphones, wireless software update and other functions.

    As the popularity of TWS Bluetooth earphones continues to rise, consumers‘ requirements for the charging base of earphones are also gradually increasing. Therefore, when manufacturing, major manufacturers should not only consider the use experience of TWS earphones, but also innovate the design of earphone charging base. In this regard, as a world-renowned integrated semiconductor solution supplier, Risa electronics integrates its own high-quality products into a successful product portfolio, providing customers with new ideas in innovative design.