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2.5V to 16V Input, 7A Switching Current High-Efficiency Buck-Boost Converter

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Product Details

Key Features

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Key Features

  • Wide Input Voltage Range: 2.5V to 16V
  • Default Output Voltage
    • 5V with Internal Feedback Resistors
    • 3V to 15V with External Feedback Resistors
  • I2C-Programmable Output Voltage after Startup
    • 4.5V to 15V with Internal Feedback Resistors
    • 3.0V to 15V with External Feedback Resistors, See Table 1
  • Maximum Output Current
    • Buck Mode: Up to 6A
    • Boost Mode: Up to 4A (Boost Ratio ≤ 1.3)
  • 7A Typical Switching Current
  • RSEL Configuration
    • I2C Interface Slave Address
    • Switching Current Limit Threshold
    • Internal/External Feedback Resistors
  • I2C Programming
    • Output Voltage (DVS)
    • Slew Rate of Output Voltage Change
    • Switching Current Limit Threshold
    • Switching Frequency
    • Forced PWM Mode Operation (FPWM)
    • Power-OK (POK) Status and Fault Interrupt Masks
  • Soft-Start
  • Output Active Discharge
  • Open-Drain Power-OK (POK) Monitor and Fault Condition Interrupt (MAX77857B/C Only)
  • Protection Features
    • Undervoltage Lockout (UVLO)
    • Overcurrent Protection (OCP)
    • Overvoltage Protection (OVP)
    • Thermal Shutdown (THS)
  • High Density Interconnect (HDI) PCB not Required (See the PCB Layout Guideline section)
  • Available in 2.83mm x 2.03mm 35 WLP or 31 WLP or 3.5mm x 3.5mm 16 FC2QFN

Applications/Uses

  • USB Power Delivery (USB-PD) OTG
  • Qualcomm® Quick ChargeTM
  • USB VBUS Supply and DRP (Dual Role Power) Ports
  • DSLR, DSLR Lens
  • Display Power
  • Up to 3-Cell Li-Ion Battery Applications
  • Notebook Computer, Tablet PC

Description

The MAX77857 is a high-efficiency, high-performance buck-boost converter targeted for systems requiring a wide input voltage range (2.5V to 16V). It features 7A switching current and can supply up to 6A output current in buck mode and up to 4A in boost mode (Boost Ratio ≤ 1.3). It operates in PWM mode and implements an automatic SKIP mode to improve light-load efficiency.

The default output voltage is 5V when using internal feedback resistors. It can also be configured to any default output voltages between 3V and 15V when using external feedback resistors. The output voltage is adjustable dynamically through the I2C serial interface (see the Output Voltage Configuration section).

The SEL pin allows a single external resistor to program four different I2C interface slave addresses, four different switching current limit thresholds, and selection between external/internal feedback resistors. The different switching current limit thresholds allow the use of lower profile and smaller external components that are optimized for a particular application. The use of external feedback resistors allows for a wider output voltage range and customizable output voltages at startup.

The I2C serial interface is optional and allows for dynamically controlling the output voltage, slew rate of the output voltage change, switching-current limit threshold, switching frequency, and forced PWM mode operation. The I2C-programmed settings have priority over the RSEL decoded settings.

The MAX77857 is available in a 2.83mm x 2.03mm, 35-bump and 31-bump wafer-level package (WLP) and a 3.5mm x 3.5mm, 16-lead Flip Chip QFN package (FC2QFN).

Simplified Block Diagram

Technical Docs

Support & Training

Search our knowledge base for answers to your technical questions.

Filtered Search

Our dedicated team of Applications Engineers are also available to answer your technical questions. Visit our support portal .