The BQ25720 is a synchronous NVDC buck-boost battery charge controller to charge a 1- to 4-cell battery from a wide range of input sources including USB adapter, high voltage USB-C Power Delivery (PD) sources, and traditional adapters.
The NVDC configuration allows the system to be regulated based on battery voltage, but not drop below system minimum voltage. The system keeps operating even when the battery is completely discharged or removed. When load power exceeds input source rating, the battery goes into supplement mode and prevents the system from crashing.
During power up, the charger sets the converter to a buck, boost, or buck-boost configuration based on the input source and battery conditions. The charger seamlessly transitions between the buck, boost, and buck-boost operation modes without host control.
In the absence of an input source, the BQ25720 supports the USB On-the-Go (OTG) function from a 1- to 4-cell battery to generate an adjustable 3-V to 24-V output on VBUS with 8-mV resolution. The OTG output voltage transition slew rate can be configured to comply with the USB-PD 3.0 PPS specification.
When only a battery powers the system and no external load is connected to the USB OTG port, the BQ25720 implements the latest Intel Vmin Active Protection (VAP) feature, in which the device charges up the VBUS voltage from the battery to store some energy in the input decoupling capacitors. During a system peak power spike, the energy stored in the input capacitors supplements the system, to prevent the system voltage from dropping below the minimum system voltage and causing a system crash.
The BQ25720 monitors adapter current, battery current, and system power. The flexibly programmed PROCHOT output goes directly to the CPU for throttle back when needed.
The latest version of the USB-C PD specification includes Fast Role Swap (FRS) to ensure power role swapping occurs in a timely fashion so that the device(s) connected to the dock can avoid experiencing momentary power loss or glitching. This device integrates FRS in compliance with the PD specification.
TI patented switching frequency dithering pattern can significantly reduce EMI noise over the whole conductive EMI frequency range (150 kHz to 30 MHz). Multiple dithering scale options are available to provide flexibility for different applications to simplify EMI noise filter design.
The charger can be operated in the TI patented Pass Through Mode (PTM) to improve efficiency over the full load range. In PTM, input power is directly passed through the charger to the system. Switching losses of the MOSFETs and inductor core loss can be saved for high efficiency operation.
The BQ25720 is available in a 32-pin 4 mm × 4 mm WQFN package.