8.2.3.1 Detailed Design Procedure

The recommended L1 = 22 µH, CBYP = 0.01 µF and low leakage CREF = 10 nF are selected. The rectifier diodes are Panasonic DB3X316F0L. In order to ensure the fastest recovery of the harvester output voltage to the MPPT level following power extraction, the minimum recommended CIN = 4.7 µF is selected. Because no large system load transients are expected and to ensure fast charge time during cold start, the minimum recommended CSTOR = 4.7 µF.

No MPPT resistors are required because VOC_SAMP can be tied to GND to give 50% MPPT.

Referring back to the procedure in Typical Applications or using the spreadsheet calculator at SLUC484 gives the following values:

• R_OV1 = 4.75 MΩ, R_OV2 = 8.25 MΩ resulting in VBAT_OV = 4.97 V due to rounding to the nearest 1% resistor.
• R_OK1 = 4.22 MΩ, R_OK2 = 8.06 MΩ, R_OK3 = 0.698 MΩ resulting in VBAT_OK = 3.5 V and VBAT_OK_HYST = 3.7 V after rounding.