Packaging information
| Package | Pins VQFN-HR (RQM) | 29 |
| Operating temperature range (°C) -40 to 85 |
| Package qty | Carrier 3,000 | LARGE T&R |
Features for the BQ25798
- High power density, high
integration buck -boost charger for 1-4 cell batteries supporting USB PD 3.0 profile
- Integrates four switching MOSFETs, BATFET
- Integrates input and charging current sensing
- Highly efficient
- 750-kHz or 1.5-MHz switching frequencies
- 5-A charging current
with 10-mA resolution
- 96.5% efficient: 16-V battery at 3A from 20V
- Supports a wide range of input sources
- Autonomously sampled open circuit voltage (VOC) maximum power point tracking (MPPT) for charging from a photovoltaic panel
- 3.6-V to 24-V wide input operating voltage range with 30-V absolute maximum rating
- Detects USB BC1.2, HVDCP and non-standard adapters
- Dual-input power mux controller (optional)
- Narrow voltage DC (NVDC) power path
- Backup Mode with Ultra-fast switchover to adjustable voltage
- Powers USB port from battery (USB
OTG)
- 2.8-V to 22-V OTG output voltage with 10-mV resolution to support USB-PD PPS
- OTG output current regulation up to 3.32 A with 40-mA resolution
- Flexible autonomous and I2C mode for optimal system performance
- Integrated 16-bit ADC for voltage, current, and temperature monitoring
- Low battery quiescent current
- 17 µA for battery only operation
- 500 nA in Charger Shutdown Mode
- High accuracy
- -0.25% to +0.65% charge voltage regulation for 2S batteries
- ±5% charge current regulation
- ±5% input current regulation
- Safety
- Thermal regulation and thermal shutdown
- Input/battery OVP and OCP
- Converter MOSFETs OCP
- Charging safety timer
- Package
- 29-Pin 4 mm × 4 mm QFN
Description for the BQ25798
The BQ25798 is a fully integrated switch-mode buck -boost charger for 1-4 cell Li-ion batteries and Li-polymer batteries. The integration includes 4 switching MOSFETs, input and charging current sensing circuits, the battery FET and all the loop compensation of the buck-boost converter. It uses NVDC power path management, regulating the system not dropping below a configurable minimum system voltage. When system power exceeds the input source rating, battery supplement mode supports the system without overloading the input source. BQ25798 also maximizes power from photovoltaic panels using its built-in VOC scaling MPPT algorithm. BQ25798 supports ultra-fast switchover from the adapter to a converted battery voltage in Backup Mode.