data/text/DLP4/900166

BQ25505: Choosing vibration element

Part Number: BQ25505 Hi everyone, We are designing a smart insole and we are willing to integrate energy harvesting (through step foot) as an auxiliary charging system. We have chosen the bq25505 charger and now we are investigating for vibration elements. We are looking for piezoelectric modules. Do you have to suggest as any piezoelectric module for our application that would be compatible with bq25505? As I mentioned this is going to be just an auxiliary charging system and we're not looking to cover our full power load. Thanks in advance Nick

Hi Nick, Unfortunately, I do not have a specific vibration element. Keep in mind the charger must always boost so the VMPP << VBAT_OV<5.5Vmax. You will likely have to use a zener clamp on the element to protect the BQ25505 input. Regards, Jeff

Hi jeff, First of all, thank you for your response!! However, I have some additional questions. 1. What you mean "charger must always boost"? 2. VMPP is the VOC_SAMP isn't it? 3. How did you choose Rsumoc = 20MΩ? 4. How did you choose VREF_SAMP = 0.14V? Thanks in advance Nick