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ut-robotics / picr22-team-kivipallur-jurto

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DRV8243 VM pins need more capacitance #23

Closed ReikoR closed 1 year ago

ReikoR commented 1 year ago

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More capacitance is needed during switching at driver's input (VM) to avoid voltage drop at the driver's output. Around 50 uF might be fine. For example it's possible to use 5x 10 uF ceramic capacitors.

ReikoR commented 1 year ago

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100uF 25V+ 0805 capacitors do not exist or are not available.

100uF 25V+ ceramic capacitors in stock at Mouser: https://www.mouser.ee/c/passive-components/capacitors/mlccs/multilayer-ceramic-capacitors-mlcc-smd-smt/?capacitance=100%20uF&voltage%20rating%20dc=25%20VDC~~50%20VDC&instock=y&rp=passive-components%2Fcapacitors%2Fmlccs%2Fmultilayer-ceramic-capacitors-mlcc-smd-smt%7C~Voltage%20Rating%20DC

ReikoR commented 1 year ago

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100 uF capacitors in 2220 package cost too much: https://www.mouser.ee/ProductDetail/Murata-Electronics/KCM55WC71E107MH13L?qs=sGAEpiMZZMvsSlwiRhF8qtsBU8Zhqm2R4ePQrDNqOw1wd48CezCu2A%3D%3D image

We already have bought 10uF 0805 capacitors. It's recommended to use about 5 of them for each driver.