Analog Devices Adds Switch-Mode Buck-Boost Charger to Power Management ICs

Analog Devices is introducing a power management IC (PMIC) with an integrated switch-mode buck-boost charger that delivers a faster charge to consumer and medical wearables and other small Internet of Things (IoT) devices.

The MAX77659 integrates a switch-mode buck-boost charger and three independently programmable buck-boost regulators, which all share the same inductor to save real estate on the circuit board (PCB). The regulators prolong the battery life of portable consumer and medical devices by operating at 91% efficiency under moderate to heavy loads. During light load conditions, the power management chip uses 5 µA of quiescent current, the company said.

The vendor said the switch-mode buck-boost charger can replenish the precious battery power in wearables and other consumer electronics, such as wireless headphones, up to four times faster than prior generations of chips. Power management ICs are frequently used in smaller battery-operated devices because they combine a number of power rails and functions into the same chip, resulting in a more efficient use of real estate and system power.

Analog Devices said a ten-minute charge with the MAX77659 delivers more than four hours of playtime compared to previous solutions that only supply one-and-a-half hours of playtime post-charge. The onboard buck-boost charger supports a programmable fast-charging current of 7.5mA to 300mA; a programmable battery regulation voltage of 3.6V to 4.6V, and a programmable termination current of 0.375mA to 45mA.

The chip also integrates an “autonomous headroom control” feature to reduce the voltage drop while offering enough headroom to regulate the charging current. That reduces the heat dissipation of the device, the company said.

Integrating the switch-mode charger and three independent regulators on the same chip reduces the bill of materials (BOM) cost of the final system by up to 60%, Analog Devices said.

A complete solution based on the MAX77659 fits within a footprint of 22-mm², or around 50% smaller than what you can do with existing PMICs. The chip is housed in a wafer-level package (WLP) that measures 6-mm².

Roger Yeung, who leads the battery power solutions business at Maxim Integrated, now part of Analog Devices, said the new chip “frees up board real estate to pack in additional features,” such as additional memory or more advanced sensors.

Analog Devices announced last month that it had closed its more than $20 billion deal to buy Maxim Integrated.