Now Maxim has introduced six of them, aimed at wearables, hearables, sensors, smart-home automation hubs and IoT devices, according to the firm.

MAX17270 for wearables and hearables
Quiescent current is 850nA when only one output is enabled, plus 200nA for each additional output enabled.
TQFN and WLP package options.

MAX77278: Power path charger for small Li+ batteries in remote controls, health monitors, fitness monitors, body cameras and IoT.
Three buck-boost 0.8-5.25V outputs, independently settable with power sequencing. 16µA operating quiescent, 300nA stand-by. Intended to charge Li+ cells with 7.5-300mA constant current, and includes an adjustable 425mA current sink for driving an LED, plus eight GPIO pins and a 3.7125-5.3V 50mA low-noise LDO with fixed headroom control. Battery temperature monitoring in included. I²C provides monitoring and control. PSUs can be as small as 24mm².

MAX77640 / MAX77641: Battery charging for wearables, fitness monitors, health monitors and IoT
Three buck-boost regulators, a low-noise 150mA LDO, a GPIO output port, a triple current sink for an RGB LED array and flexible power sequencing. Operating current is 5.6µA, with 300nAshut-down. 16mm² PSU possible.

MAX77680 / MAX77681: Always-on in Bluetooth headsets and earbuds, and IoT devices  rings, watches, e-pens
Three buck-boost regulators, 3.0µA operation and 300nA shutdown, with flexible power sequencing. Possible 15.5mm² PSU. Given their feature set, the MAX77680 and MAX77681 are ideal for more minimalistic platforms that require streamlined resources, such as .

“The challenge facing developers is how to include the processor, high-quality audio, near-field communication, wireless connectivity and multiple sensors in wearable form factors that conserve precious battery life and manage the thermals, given that these devices often come in contact with heat-sensitive skin,” said Maxim business director Karthi Gopalan.

All are available from Maxim or selected distributors.