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Announcement: Introducing HL8545/G: Quad-Channel 50 mΩ High-Side Switch for Advanced Automotive Applications


The HL7509FNQ is a synchronous buck converter optimized to supply low-voltage applications. Its input voltage range is 2.5-5.5V. Its output voltage range is 0.6-1.23V programmed through an I2C interface. Its output voltage can be adjusted on the fly to provide dynamic voltage scaling (DVS) function with a programmable slew rate.

The HL7509FNQ maintains good efficiency for a wide range of load. It delivers a maximum 5A RMS load current while spurious load up to 8A can be supported for 10ms duration. It operates at fixed frequency of 2.4MHz, which reduces the value of the external components. A wide range of output capacitors can be used to optimize VOUT excursion during load transients. The inductors from 0.22μH to 1.0μH may be used without affecting loop stability.

At moderate to light load, the pulse frequency modulation (PFM) is used to maintain conversion efficiency with a typical non-switching quiescent current of 70µA. Even with such a low quiescent current, the HL7509FNQ maintains excellent load and line transient responses. At higher loads, the system automatically switches to fixed-frequency pulse width modulation (PWM) operation at for minimum VOUT ripple and optimal load transient response. In shutdown mode, the supply current drops below 1µA and reduces a power consumption. The PFM mode can be disabled if needed through I2C registers.

For more detailed description of the device, please download a product brief.



  • Input voltage ranges: 2.5-5.5V
  • Programmable output voltage
    • 0.600-1.230V in 10mV steps
  • Maximum output current
    • 5A Continuous, 8A peak for 10ms
  • VOUT remote sensing capable for point-of-load operation
  • 2.4MHz PWM with seamless PWM/PFM switching for light-load efficiency
  • Dynamic voltage scaling (DVS) with programmable voltage slew rate
  • Class-leading load and line transient
  • Quiescent current in PFM tristate: 70µA
  • I2C Interface with SM, FM, FM+ and HS modes
  • Comprehensive protections
    • Output under-voltage lockout (OVLD)
    • Input over-voltage protection (OVP)
    • Over-current and short-circuit protections
    • Thermal shut-down
  • 4mm x 3mm 14-pin DFN package
  • AEC-Q100 qualified grade 3, automotive temperature ranges (-40°C to +85°C)

Block Diagram

HL7509FNQ - HMI Main Photo

For more information or a full datasheet request, please contact the factory at

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