BQ24079QWRGTTQ1

• Qualified for Automotive Applications
• AEC-Q100 Qualified with the Following Results:
  • Device Temperature Grade 1: -40°C to +125°C Ambient OperatingTemperature Range
  • Device HBM ESD Classification Level 2
  • Device CDM ESDClassification Level C4A
• Fully Compliant USBCharger
  • Selectable 100-mA and 500-mA Maximum Input Current
  • 100-mA Maximum Current Limit Ensures Compliance to USB-IF Standard
  • Input Based Dynamic Power Management (VIN-DPM) forProtection Against Poor USB Sources
• 28-V Input Rating with Overvoltage Protection
• 4.1-V Battery Regulation Voltage
• Integrated Dynamic Power-PathManagement (DPPM) Function Simultaneously and Independently Powers the System and Charges theBattery
• Supports up to 1.5-A Charge Current with Current Monitoring Output(ISET)
• Programmable Input Current Limit up to 1.5 A for Wall Adapters
• Battery Disconnect Function with SYSOFF Input
• Programmable Pre-Charge and Fast-Charge Safety Timers
• Reverse Current, Short-Circuit, and Thermal Protection
• NTC Thermistor Input
• Proprietary Start Up Sequence Limits Inrush Current
• Status Indication – Charging/Done, Power Good
• Small 3 mm × 3 mm 16 Lead VQFN Package with Wettable Flank

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The bq24079QW-Q1 is an integrated Li-ion linear charger and system power-path managementdevice targeted at space-constraint automotive applications such as telematics/eCall. The devicecan operate from 4.35 V to 6.4 V and support charge currents up to 1.5 A. The input voltage rangewith input overvoltage protection supports unregulated adapters. The USB input current limitaccuracy and start up sequence allow the bq24079QW-Q1 to meet the USB-IF inrush currentspecification. Additionally, the input dynamic power management (VIN-DPM)prevents the system load from crashing incorrectly configured USB sources.

The bq24079QW-Q1 features dynamic power-path management (DPPM) that powers the systemwhile simultaneously and independently charging the battery. The DPPM circuit reduces the chargecurrent when the input current limit causes the system output to fall to the DPPM threshold; thus,supplying the system load at all times while monitoring the charge current separately. This featurealong with the 4.1-V battery regulation voltage helps to extend battery life time by reducing thenumber of charge and discharge cycles on the battery, allowing for proper charge termination andenabling the system to run with a defective or absent battery pack.

Additionally, the regulated system input enables instant system turn-on when plugged ineven with a totally discharged battery. The power-path management architecture also permits thebattery to supplement the system current requirements when the adapter cannot deliver the peaksystem currents, enabling the use of a smaller adapter.

The battery is charged in three phases: conditioning, constant current, and constantvoltage. In all charge phases, an internal control loop monitors the IC junction temperature andreduces the charge current if the internal temperature threshold is exceeded. The charger powerstage and charge current sense functions are fully integrated. The charger function has highaccuracy current and voltage regulation loops, charge status display, and charge termination. Theinput current limit and charge current are programmable using external resistors.