Step-down buck converter saves space in multi-cell battery applications

Analog Devices Inc. has launched the MAX77540 step-down buck converter for single-stage power conversion in multi-cell battery applications. These include augmented reality/virtual reality (AR/VR) headsets, land mobile radios (LMRs) and digital single-lens reflex (DSLR) cameras.

Click for a larger image. (Source: Analog Devices Inc.)

The MAX77540 buck converter offers 94 percent peak efficiency (7.6 VIN, 3.3 VOUT, 1 MHz), which helps extend battery life. The device features a wide 4-V to 16-V input voltage range and a 0.5-V to 5.2-V output voltage range. The output voltages are preset with resistors and are adjustable via the I2C interface.

Available in a 30-bump wafer-level package (WLP), measuring 2.51 × 2.31 mm, the MAX77540 is 61 percent smaller traditional quad flat no-lead (QFN) packages.

“Multi-cell battery applications require two stage power conversion and long battery life in the smallest package possible. Traditional methods, such as using a front-end converter to step down to  5 V or below, and subsequently, stepping down further to system level voltages, are inefficient and therefore impact the battery life of the system,” said Analog Devices. “This approach requires an additional converter, which often requires an inductor, ultimately driving a larger solution footprint and higher cost.”

The MAX77540 allows design engineers to create either dual 3-A or a single 6-A output(s). The two 3-A switching phases provide single-step conversions to core voltages from USB-C rails and 2S and 3S multi-cell batteries.

MAX77540 typical applications circuit (Source: Analog Devices Inc.)

The default power on configuration only requires two external resistors, said the company, while the I2C interface delivers additional control for advanced power management techniques. External frequency tracking and spread spectrum modulation provide low electromagnetic interference (EMI) power conversions for data sensing and processing equipment.

The MAX77540 is available in volume production. An evaluation kit, the MAX77540EVKIT, also is available.