Single-/Multi-cell MAX20361 Solar Harvester for Increased Runtime in Space-Constrained Wearable and IoT Applications

MAX20361 Solar Harvesting Solution

Maxim Integrated has introduced the MAX20361 single-/multi-cell solar harvester with maximum power point tracking (MPPT) that can significantly increase the runtime of space-constrained applications such as wearables and emerging IoT applications. The new device also increases harvested energy with up to 5 percent better boost efficiency and reduces the solution size by at least half compared to the closest competitor.


The device comes with an ultra-low quiescent current (360nA) boost converter that is capable of starting from input voltages as low as 225mV (typ). The maximum power point tracking (MPPT) of the device also improves the overall system-level efficiency from 15μW to over 300mW.


The MAX20361 solar harvesting solution features an integrated charging and a protection circuit that is optimized for Li-ion batteries. The charger also features a programmable charging cut-off voltage with thresholds programmable through the I2C interface as well as temperature shutoff. The device is available in a 12-bump, 0.4mm pitch, 1.63 mm x 1.23 mm wafer-level package (WLP).


Features of MAX20361 Solar Harvesting Solution

  • 225mV to 2.5V (typ) Input-Voltage Range
  • Efficient Harvesting from 15μW to Over 300mW of Available Input Power - 86% Efficiency at VSYS = 3.8V, ISRC = 30mA
  • Small Solution Size - Utilizes Small 2016 4.7μH Inductor
  • Maximum Power Point Tracking (MPPT) Technique Using Fractional VOC Method
  • Programmable Fractional VOC Regulation Point through I2C Interface
  • Programmable Battery Termination Voltage through I2C Interface
  • Programmable Power Good Wake-Up Signal Output Threshold through I2C Interface