PMICs shrink power regulator size in half for IoT devices
Designers of small, battery-powered electronics can enhance the user experience by extending battery life and further shrinking device size with six new low power power-management integrated circuits (PMICs) from Maxim Integrated. The MAX17270, MAX77278, MAX77640/MAX77641 and MAX77680/MAX77681 PMICs help to reduce the power management footprint by up to 50% for space-constrained products such as wearables, hearables, sensors, smart-home automation hubs and IoT devices.
They increase the overall system efficiency by nine percent compared to the closest competitive solution, while also reducing heat dissipation, an important consideration for wearable products that make skin contact.
Designers are striving to make electronic gadgets more integral in consumers’ lives by scaling down their form factor, reducing heat, improving efficiency and extending battery life. Meeting each of these criteria is a formidable challenge given the rich feature sets, lower thermal thresholds and smaller capacity batteries required to achieve increasingly compact solution sizes.
Maxim is expanding its portfolio of SIMO PMICs to enable designers to overcome these challenges, continuing the compact size and efficiency precedents set by MAX77650/MAX77651. The unique control architecture in the MAX17270, MAX77278, MAX77640/MAX77641 and MAX77680/MAX77681 PMICs allows a single inductor to serve as the critical energy-storage element for multiple, independent DC-rail outputs.
This allows engineers to reduce the number of bulky inductors in their designs, thereby improving efficiency, shrinking form factor and reducing heat dissipation. In addition, the low quiescent current of the PMICs plays an important role in extending battery life. With the intrinsic buck-boost operation of the PMICs, the power rails can operate over a battery’s entire range.
MAX17270: Smallest size and lowest quiescent current
At 50% smaller than previous-generation SIMO-only solutions, the MAX17270 SIMO buck-boost converter provides the industry’s smallest solution size while reducing the number of inductors and ICs that are required for a power tree. Its quiescent current of 850nA for one SIMO channel and 1.3µA for three SIMO channels is the lowest in the market and helps extend battery life of end devices.
In addition, the product’s low power consumption prevents overheating and reduces frequent charging cycles for wearables and hearables. They are available in TQFN and WLP package options.
MAX77278: Power path charger optimised for small Li+ batteries
This ultra-low power SIMO PMIC provides three buck-boost regulators with independent voltage outputs (0.8VOUT to 5.25VOUT), 16µA operating quiescent current/300nA standby current and flexible power sequencing. The device is also a charger for small Li+ cells (7.5mA – 300mA CC range).
It includes an adjustable 425mA current sink for an LED, eight general-purpose input/output (GPIO) pins and a 3.7125V to 5.3V, 50mA low-noise low-dropout regulator (LDO) with fixed headroom control in a total solution size as low as 24mm².
The PMIC’s I²C interface allows an applications processor to monitor the status and control power management. The MAX77278 is suitable for remote controls, health and fitness monitors, body cameras and IoT applications.
MAX77640/MAX77641: Highly integrated battery charging and power solutions
These ultra-low power SIMO PMICs feature 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 just 5.6µA and shutdown current is 300nA. Available in a 16mm² total solution size, the MAX77640 and MAX77641 are suitable for applications with a built-in charger in areas like wearables, fitness and health monitoring and IoT.
MAX77680/MAX77681: Mini PMICs for always-on, low power applications
These ultra-low power SIMO PMICs provide three buck-boost regulators, 3.0µA operating quiescent current, 300nA shutdown current and flexible power sequencing.
Total solution size is only 15.5mm². Given their feature set, the MAX77680 and MAX77681 are ideal for more minimalistic platforms that require streamlined resources, such as hearables (Bluetooth headsets/earbuds) and miniaturised IoT devices (rings, watches, e-pens).
“As small, connected mobile devices become more sophisticated, they also require more power rails,” said Kevin Anderson, Senior Analyst, Power IC Research at IHS Markit.
“Any technology that allows designers to add functionality, reduce form factor and improve power management simultaneously will find interest among developers who need to shrink the design footprint of their devices to make them more attractive to end users.”
“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 Karthi Gopalan, Director of Business Management, Mobile Power Business Unit, Maxim Integrated.
“These SIMO PMICs continue our tradition of providing one-stop power management solutions for a wide range of next-generation, low power designs.”