Maxim Integrated MAX77756 flexible buck converter

Developers of multicell, USB Type-C products that need high current, dual input and I²C support now have a flexible option with the MAX77756 24 V, 500 mA, low quiescent current (Iq) buck converter from Maxim Integrated.

USB Type-C products must generate an always-on 3.3 V rail to detect USB insertions. Products utilising the Power Delivery (PD) voltage range (5 to 20 V) can generate an always-on (1.8/3.3/5 V) digital supply rail for the port controller using the MAX77756 step-down converter. In addition, the converter has a 20 μA quiescent current that extends battery life by reducing idle power consumption. To simplify the system design, the product has a dual input-friendly diode ORing circuit that allows the chip to power from the external USB source if the battery is empty.

Multicell battery-operated devices can easily evolve to Type-C with PD using the flexible MAX77756 power supply. The product has a combination of wide input voltage range, low quiescent current (1.5 μA buck), high current load, dual input and I²C for flexibility and programmability. There is also a default power mode if users do not want to use the I²C bus.

The robust IC features short-circuit and thermal protection, 8 ms internal soft-start to minimise inrush current, current-mode control architecture and up to 26 V input voltage standoff. Measuring 2.33 x 1.42 mm, the product saves board space and reduces series voltage drop by integrating FETs, eliminating the need to use external Schottky diodes.