Extend Battery Life of USB Type-C™ Devices with Maxim’s Flexible Buck Converter

Developers of multi-cell, USB Type-C products that need higher current, dual input, and I²C support now have a flexible option with the MAX77756 24V, 500mA, low quiescent current (Iq) buck converter from Maxim Integrated Products, Inc. (NASDAQ: MXIM).

USB Type-C products must generate an always-on 3.3V rail to detect USB insertions. Products utilizing the Power Delivery (PD) voltage range (5V to 20V) can generate an always-on (1.8V/3.3V/5.0V) digital supply rail for the port controller using the MAX77756 step-down converter. In addition, the MAX77756 has a 20µA quiescent current that extends battery life by reducing idle power consumption. To simplify the system design, the MAX77756 has a dual input ideal diode ORing circuit that allows the chip to power from the external USB source if the battery is empty.

Multi-cell battery-operated devices—such as ultrabooks, laptops, tablets, drones, and home automation appliances—can easily evolve to Type-C with PD using the flexible MAX77756 power supply. The MAX77756 has a unique combination of wide input voltage range, low quiescent current, higher current load, dual input, and I²C for flexibility and programmability. There is also a default power mode if customers do not want to use the I²C bus. The MAX77756 is a robust IC with short-circuit and thermal protection, 8ms internal soft-start to minimize inrush current, proven current-mode control architecture, and up to 26V input voltage standoff.

Key Advantages

• Low quiescent current: 1.5µA Buck and 20µA MUX for always-on operation
• High efficiency: Up to 92% with integrated power MUX
• Small solution size: 2.33mm x 1.42mm 15-bump WLP; no external Schottky array needed
• Wide input voltage: Operates on full VBUS range (5V-20V) and VBATT (2S, 3S, 4S Li+)

Commentary

“The MAX77756 saves board space and reduces series voltage drop by integrating FETs, eliminating the need to use external Schottky diodes,” said Jia Hu, Executive Business Manager, Mobile Power, Maxim Integrated. “The MAX77756 also helps engineers minimize power consumption and extend battery life for the end application by offering highest efficiency and lowest Iq compared to other products.”

Availability and Pricing

• MAX77756 is available from stock and priced at $0.65 (10,000-up, FOB USA)
• MAX77756EVKIT# is available from stock and priced at $70
• Start designing with MAX77756 now using the EE-Sim® Tool Suite, https://bit.ly/EE-Sim
• More information: https://bit.ly/MAX77756
• EV Kit image: https://bit.ly/MAX77756_EVKit_image
• Block diagram: https://bit.ly/MAX77756_diagram
• Application circuit diagram: https://bit.ly/MAX77756_application_circuit