Ultra-low power PMIC for optical signal measurement with the highest sensitivity

     Maxim announced the launch of a new miniature, highly integrated power management IC (PMIC) to provide an easier design approach to uninterruptable power supply for wearable products, Internet of Things (IoT) and other devices, helping designers significantly reduce the size of the solution while increasing battery uptime. The MAX20345 ultra-low power integrated lithium battery charger uses Maxim's unique technology for highly sensitive optical measurement applications, making it ideal for wearable fitness and health applications.

     In wearable devices, the user's biological signs will affect the optical detection accuracy. Designers are always working to improve the sensitivity of optical systems, especially the signal-to-noise ratio (SNR), to cover a wider spectral range. Traditional low-static current regulators are favored in wearable applications, but they also have drawbacks, such as higher low-frequency ripple, longer build up time, and reduced SNR for wrist detection.

     Some designers are turning to alternatives with higher static currents to overcome these shortcomings, but at the cost of increased power consumption, resulting in shorter battery run times or the need to replace larger batteries. Tailored for high-precision heart rate, blood oxygen (SpO2) and other optical measurement applications, the MAX20345 uses the innovative buck-boost architecture first introduced by Maxim. The regulator provides optimal low static current characteristics without decreasing SNR, resulting in a performance increase of up to 7dB, depending on the measurement conditions.

     The MAX20345 is also the latest member of the ultra-low power PMIC product family, which is ideal for small size wearable and IoT devices to increase efficiency without reducing battery run time. To meet the design requirements, the MAX20345 integrates a lithium-ion battery charger, six ultra-low static current voltage regulators, three nanoPower buck regulators (typical value is 900nA), and three ultra-low static current Ldos (typical value is as low as 550nA).

     2 load switches allow system peripherals to be disconnected to minimize battery leakage. Both Buck-Boost and buck regulators support dynamic voltage regulation (DVS), operating at lower voltages in good conditions for additional power savings. The MAX20345 is available in a 56-ball, 0.4mm weld length, 3.37mm x 3.05mm wafer-level package (WLP).