Product details

Number of series cells 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 Charge current (max) (A) 20 Vin (max) (V) 70 Cell chemistry Lead Acid Battery charge voltage (min) (V) 0 Battery charge voltage (max) (V) 70 Absolute max Vin (max) (V) 85 Control topology Switch-Mode Buck-boost Control interface I2C Features Adjustable switching frequency, BAT temp thermistor monitoring (JEITA profile), Bidirectional, IC thermal regulation, ICO (Input Current Optimization), IINDPM (Input current limit), Input OVP, Integrated ADC, Integrated LDO, Power Path, SYNC Pin, USB C/PD compatible, VINDPM (Input voltage threshold to maximize adaptor power) Vin (min) (V) 4.2 Rating Catalog Operating temperature range (°C) -40 to 125
Number of series cells 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16 Charge current (max) (A) 20 Vin (max) (V) 70 Cell chemistry Lead Acid Battery charge voltage (min) (V) 0 Battery charge voltage (max) (V) 70 Absolute max Vin (max) (V) 85 Control topology Switch-Mode Buck-boost Control interface I2C Features Adjustable switching frequency, BAT temp thermistor monitoring (JEITA profile), Bidirectional, IC thermal regulation, ICO (Input Current Optimization), IINDPM (Input current limit), Input OVP, Integrated ADC, Integrated LDO, Power Path, SYNC Pin, USB C/PD compatible, VINDPM (Input voltage threshold to maximize adaptor power) Vin (min) (V) 4.2 Rating Catalog Operating temperature range (°C) -40 to 125
VQFN (RRV) 36 30 mm² 6 x 5
  • Wide input voltage operating range: 4.4V to 70V
  • Wide battery voltage operating range: up-to 70V
    • 6V up-to 48V lead-acid charging profile with bulk, absorb and float voltage charging phases
    • Charge voltage temperature compensation
  • Synchronous buck charge controller with NFET drivers
    • Adjustable switching frequency from 200kHz to 600kHz
    • Optional synchronization to external clock
    • Integrated loop compensation with soft start
    • Optional gate driver supply input for optimized efficiency
  • Bidirectional converter operation (Reverse Mode) supporting USB-PD Extended Power Range (EPR)
    • Adjustable input voltage (VAC) regulation from 3.3V to 65V with 20mV/step
    • Adjustable input current regulation (RAC_SNS) from 400mA to 20A with 50mA/step using 2mΩ resistor
  • Direct power path management for highest efficiency to power system
    • System power selection from adapter or battery
    • Dynamic power management
    • All N-channel FET drivers
  • High accuracy
    • ±0.5% charge voltage regulation
    • ±3% charge current regulation
    • ±3% input current regulation
  • I2C controlled for optimal system performance with resistor-programmable option
    • Hardware adjustable input and output current limits
  • Integrated 16-bit ADC for voltage, current, and temperature monitoring
  • Low battery quiescent current
  • High safety integration
    • Adjustable input overvoltage and undervoltage protection
    • Battery Overvoltage and overcurrent protection
    • Charging safety timer in CV Mode
    • Thermal shutdown
  • Status outputs
    • Adapter present status (PG)
    • Charger Operation status
  • Package
    • 36-pin 6mm × 5mm QFN
  • Wide input voltage operating range: 4.4V to 70V
  • Wide battery voltage operating range: up-to 70V
    • 6V up-to 48V lead-acid charging profile with bulk, absorb and float voltage charging phases
    • Charge voltage temperature compensation
  • Synchronous buck charge controller with NFET drivers
    • Adjustable switching frequency from 200kHz to 600kHz
    • Optional synchronization to external clock
    • Integrated loop compensation with soft start
    • Optional gate driver supply input for optimized efficiency
  • Bidirectional converter operation (Reverse Mode) supporting USB-PD Extended Power Range (EPR)
    • Adjustable input voltage (VAC) regulation from 3.3V to 65V with 20mV/step
    • Adjustable input current regulation (RAC_SNS) from 400mA to 20A with 50mA/step using 2mΩ resistor
  • Direct power path management for highest efficiency to power system
    • System power selection from adapter or battery
    • Dynamic power management
    • All N-channel FET drivers
  • High accuracy
    • ±0.5% charge voltage regulation
    • ±3% charge current regulation
    • ±3% input current regulation
  • I2C controlled for optimal system performance with resistor-programmable option
    • Hardware adjustable input and output current limits
  • Integrated 16-bit ADC for voltage, current, and temperature monitoring
  • Low battery quiescent current
  • High safety integration
    • Adjustable input overvoltage and undervoltage protection
    • Battery Overvoltage and overcurrent protection
    • Charging safety timer in CV Mode
    • Thermal shutdown
  • Status outputs
    • Adapter present status (PG)
    • Charger Operation status
  • Package
    • 36-pin 6mm × 5mm QFN

The BQ25751 is a wide input voltage, switched-mode buck-boost battery charge controller with direct power path control. The device offers high-efficiency battery charging over a wide voltage range with bulk, float and absorption charging for lead-acid batteries. The device integrates all the loop compensation for the buck-boost converter, thereby providing a high density solution with ease of use.

Besides the I2C host-controlled charging mode, the device also supports standalone charging mode via resistor programmable limits. Input current, charge current and charge voltage regulation targets can be set via the ILIM_HIZ, ICHG and FB pins, respectively.

The BQ25751 is a wide input voltage, switched-mode buck-boost battery charge controller with direct power path control. The device offers high-efficiency battery charging over a wide voltage range with bulk, float and absorption charging for lead-acid batteries. The device integrates all the loop compensation for the buck-boost converter, thereby providing a high density solution with ease of use.

Besides the I2C host-controlled charging mode, the device also supports standalone charging mode via resistor programmable limits. Input current, charge current and charge voltage regulation targets can be set via the ILIM_HIZ, ICHG and FB pins, respectively.

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Technical documentation

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* Data sheet BQ25751: Standalone/I2C Controlled, 70V Bidirectional Buck-Boost Lead Acid Battery Charge Controller with Direct Power Path Control datasheet PDF | HTML 08 Dec 2024
EVM User's guide BQ25751 Evaluation Module User's Guide PDF | HTML 04 Dec 2024

Design & development

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Evaluation board

BQ25751EVM — BQ25751 evaluation module

The BQ25751EVM evaluation module (EVM) is a complete evaluation system for the BQ25751 IC, a buck-boost battery charge controller with a wide input range of 4.4V to 70V, a wide output voltage range of up to 70V, and bidirectional capabilities. The BQ25751EVM has a max input and output of 55V and a (...)
User guide: PDF | HTML
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VQFN (RRV) 36 Ultra Librarian

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