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| SM72442: question of I2C write data sequence. | |
| Part Number: SM72442 in the datasheet of SM72442, for I2C write sequence there is 8 data bytes from frame 4 to frame 11. if frame 4 is data 1, why frame 11 is data 7(it should be data 8)? ,and one of I2C registers is 7 bytes long, why write 8 bytes data? | |
| Hi i think it should be a typo. the data bytes is 7 instead of 8 from frames 5 to 11. I don't have EVM as it is quite old device. do you have an IC to try? | |
| thank you so much. I am writing the software , so should i think the frame 11 is no need. please check page 14 of the datasheet of SM72442, NOW the hardware is not ready ,so i cannot test on the software ,but i want to write the right sofeware. | |
| Hi, i think you are right. the data is from frame 4~ frame 10. I will also try this after getting the EVM. | |
| Hi User, sorry for the late, but i'm still waiting for the EVM. thanks for your understanding. | |
| Hi User, i got the EVM, and will try the I2C. what is the status in your side? | |
| Hi, your understanding is correct. the data frame should be from 4 to 10. the 11 is not need. let me know you see issue. | |
| THANK YOU for your work, I think this problem is fixed, now I change this chip to 72445 , 72442 need so high frequency PWM ， my NMOS can not work well, MY another question ,do you have saw it? | |
| Hi Sorry, which question do you refer to? | |
| IT is difficult to Calculate the value of inductance and capacitance, I have find the ripple of No load output Voltage achieved 20%, the inductance is 22UH capacitance is one single Electrolytic capacitor of 330uf。 the load is BLDC motor ， not charge for battery, is some problem ?? can you check for me ,of course if you have time, thank you if you have time I will send to the Schematic diagram, now I hope you just give some advice about how to select the inductance and capacitance. best regard | |
| could you share the schematic? also share the VIN and VOUT waveform to show that your observation. | |