SLUSEK7 September 2024 BQ25773
PRODUCTION DATA
Refer to the PDF data sheet for device specific package drawings
The charger can be operated in the pass through mode (PTM) to improve efficiency. In PTM, the Buck and Boost high-side FETs (Q1 and Q4) are both turned on, while the Buck and Boost low-side FETs are both turned off. The input power is directly passed through the charger to the system. The switching losses of MOSFETs and the inductor core loss are saved. The charger quiescent current under PTM mode is also minimized (around 2.5 mA) to increase light load efficiency.
When programmable power supply (PPS) is used as input adapter, PTM mode can also be leveraged to achieve battery flash charge under battery fast charge period. By enabling flash charge, the charge efficiency can be further improved with even higher charging current. During pre-charge and termination period the charger can go back to buck-boost mode.
The charger can exit PTM to buck-boost operation and automatically return to PTM under certain protection scenarios (TI patent).
To prevent reverse boost back after adapter removal when charger is in PTM operation before removal. There is light load PTM auto exit feature which can be enabled by configuring PTM_EXIT_LIGHT_LOAD=1b.
Charger will be transition from normal Buck-Boost operation to PTM operation by setting EN_PTM = 1b; and will transition out of PTM mode with host control by setting EN_PTM =0b.