Tailored for high-precision heart rate and SpO2 optical inspection for wearable and IoT applications

The MAX20345 integrates buck-boost for high-precision heart rate and SpO2 optical inspection for wearable and IoT applications

Today, Maxim Integrated Products, Inc (NASDAQ: MXIM) announces the latest introduction of a miniature, highly integrated power management IC (PMIC) that provides easier design for uninterrupted power supply issues for devices such as wearables and the Internet of Things (IoT). The method helps designers significantly reduce the size of the solution while extending battery run time. The MAX20345 ultra-low-power integrated lithium battery charger features Maxim's unique technology for high-sensitivity optical measurement applications, making it ideal for wearable fitness and wellness applications.

In wearable devices, the user's biological signs affect the accuracy of optical detection. Designers are always working to increase the sensitivity of optical systems, especially signal-to-noise ratio (SNR), to cover a wider spectral range. Traditional low quiescent current regulators are favored in wearable applications, but also have drawbacks such as higher low frequency ripple, longer settling time, and reduced SNR for wrist detection. Some designers are turning to alternatives with higher quiescent currents to overcome these shortcomings, but at the expense of increased power consumption, which reduces battery run time or the need to replace larger batteries. The MAX20345 is tailored for high-precision heart rate, blood oxygenation (SpO2) and other optical measurement applications, using the innovative buck-boost architecture first introduced by Maxim. The regulator provides the best low quiescent current characteristics without reducing SNR, resulting in performance up to 7dB (depending on measurement conditions).

The MAX20345 is also the newest member of the ultra-low-power PMIC product family, making it ideal for small form factor wearable and IoT devices that increase efficiency without compromising battery run time. To meet design requirements, the MAX20345 integrates a 1-channel Li-Ion battery charger, six ultra-low quiescent current-voltage regulators, three nanoPower buck regulators (typically 900nA), and three ultra-low quiescent current LDOs (typically low) To 550nA). Two load switches allow system peripherals to be disconnected, minimizing battery leakage. Both the buck-boost and buck regulators support dynamic voltage scaling (DVS), which operates at lower voltages in a good environment and saves additional power. The MAX20345 features a 56-bump, 0.4mm pitch, 3.37mm x 3.05mm wafer level package (WLP).

Main advantage

Excellent performance for supporting optical systems: The integrated buck-boost output has low ripple and high frequency without interfering with optical measurements. The short settling time is ideal for high sensitivity optical sensor measurements on wearable devices.

Extend battery life: The nanoPower regulator features ultra-low quiescent current to reduce sleep and standby power consumption, which extends battery run time and allows for smaller battery sizes. Energy-efficient regulators help the device save battery power while in operation.

Small size: The MAX20345 eliminates multiple discrete components and provides a high-precision power supply design for space-constrained wearable and IoT designs.


"By 2020, the sales of fitness and health wearable electronic devices are expected to exceed 114 million units, and the market demand for high-precision detection technology for measuring health indicators such as heart rate and blood oxygen will become higher and higher."

-- Kevin Anderson, Senior Power Semiconductor Analyst, IHS Markit

“Maxim has been committed to leading the way in innovation in the wearable health sector. The newly released MAX20345 expands Maxim's patent portfolio of ultra-low power PMICs for wearable and continuous power applications, providing the highest sensitivity optical inspection solution available in the market. Achieve higher precision vital sign measurements in small size designs such as wrist wear."

-- Frank Dowling, Director of Business Management, Maxim Integrated Industrial & Healthcare