Solution for Synchronous NVDC Buck/Boost Battery Charge Controller BQ25713

“The BQ25713/BQ25713B can charge the battery from various input sources including USB adapters, high voltage USB PD sources and legacy adapters. This device is a synchronous NVDC buck/boost battery charge controller that provides a low-component count, efficient solution for space-constrained 1- to 4-cell battery charging applications.

“

The BQ25713/BQ25713B can charge the battery from various input sources including USB adapters, high voltage USB PD sources and legacy adapters. This device is a synchronous NVDC buck/boost battery charge controller that provides a low-component count, efficient solution for space-constrained 1- to 4-cell battery charging applications.

With NVDC configuration, the system voltage can be stabilized at the battery voltage level, but cannot be lowered below the system minimum voltage. The system continues to function even when the battery is fully discharged or removed. When the load power exceeds the input source rating, the battery enters a recharge 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 automatically switches between buck, boost, and buck/boost configurations without host control.

Solution for Synchronous NVDC Buck/Boost Battery Charge Controller BQ25713

In the absence of an input source, the BQ25713/BQ25713B can support USB On-the-Go (OTG) for 1 to 4 cells, generating an adjustable voltage from 3V to 20.8V on VBUS with 8mV resolution. The OTG output voltage slew rate is configurable, which complies with the USB PD 3.0 PPS specification.

When the system is powered only from the battery and no external load is connected to the USB OTG port, the BQ25713/BQ25713B supports the Vmin Active Protection (VAP) feature, which allows the device to charge from the battery to VBUS to store some of the energy in into the decoupling capacitor. During peak system power spikes, a large amount of current flows from the battery, resulting in a large voltage drop across the impedance from the battery to the system. The energy stored in the input capacitors replenishes the system, preventing the system voltage from dropping below the minimum system voltage and causing the system to crash. The Vmin Active Protection (VAP) feature is designed to absorb system power spikes during high SOC power demands, and Intel strongly recommends this feature for platforms with 1 to 2 cells.

The BQ25713/BQ25713B monitors adapter current, battery current, and system power. The flexibly programmable PROCHOT output goes straight to the CPU, whose frequency can be reduced as needed.

Ideal for USB Power Delivery (PD) battery charging applications such as power banks or other portable devices. It uses the buck/boost charger BQ25713 to achieve a wide input and output range for USB PD charging. The USB PD controller card (PMP40442) can configure the charger for charging or OTG over the same power path. The PMP40441/2 are PD2.0 compatible. It also demonstrates that the BQ25713 can meet the PD’s Programmable Power Supply (PPS) standard. In the OTG direction (that is, using the power bank as a power source), the USB port can output a fixed USB PD voltage of 5/9/15/20V and a USB PD PPS voltage of 3.3V to 5.9/11/21V, with a step less than 20mV. A USB-A port dedicated to powering OTG is also included.