ADI's MAX77859 is a high-efficiency, high-performance buck-boost converter targeted for systems requiring a wide input voltage range (2.5 V to 22 V). The IC can supply up to 6 A of output current in buck mode and 4 A in boost mode (V_IN = 3.7 V, V_OUT = 5 V). The IC allows systems to change the output voltage dynamically through the I²C serial interface. MAX77859A features an I²C-adjustable output current limit with resolutions of 50 mA/step (with 10 mΩ sense resistance) to support USB-C® PPS requirements. MAX77859B is a non-PPS version and is optimized for low quiescent current. Systems equipped with MAX77859 can provide fast-charging peripheral devices with higher output voltage, minimizing power loss across cable/connector and reducing charging time.

Depending on the operating conditions, the IC operates either in SKIP mode or forced-PWM (FPWM) mode to optimize efficiency. The default output voltage is 5 V when using internal feedback resistors. The IC can also be configured to any default output voltages between 3 V and 20 V when using external feedback resistors. The output voltage is adjustable dynamically (DVS) between 3.2 V and 16 V in 20 mV steps when using internal feedback resistors or between 3 V to 20 V when using external feedback resistors (with step size dependent on the external feedback resistor ratio) by programming the internal reference voltage through I²C serial interface.

MAX77859A features output current limit. Using a 10 mΩ sense resistor, the output current limit threshold is adjustable dynamically between 1 A and 5 A in 50 mA steps through an I²C serial interface with a 3 A default value.

The SEL pin allows a single external resistor, RSEL, to connect to AGND to program the following:

• I²C interface target address (4 options)
• Switching current limit threshold (4 options)
• Feedback resistor selection (internal or external)

The MAX77859WEVKIT# evaluation kit (EV kit) is a fully assembled and tested printed circuit board (PCB) that demonstrates the high-efficiency, high-performance buck-boost MAX77859 regulator. The EV kit is factory-configured as internal feedback with a default startup output voltage of 5 V. Other startup voltages can be achieved with external feedback resistors.