{ "ticketNumber" : "887790", "reporterName" : "user6136286", "rankPoints" : "60", "resolutionStatus" : "TI Thinks Resolved", "ticketName" : "SM72442: question of I2C write data sequence.", "rankName" : "Prodigy", "replies" : " 11", "views" : " 60", "queryText" : "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?", "partNumber" : " SM72442", "allResponseList" : [ { "contentId" : "3282665", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Mar 11, 2020 11:49 AM", "userId" : "3706612", "content" : "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?" }, { "contentId" : "3283646", "userName" : "user6136286", "rankPoints" : "60", "rankName" : "Prodigy", "date" : "Mar 12, 2020 1:04 AM", "userId" : "6136286", "content" : "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." }, { "contentId" : "3292003", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Mar 20, 2020 1:10 AM", "userId" : "3706612", "content" : "Hi, i think you are right. the data is from frame 4~ frame 10. I will also try this after getting the EVM." }, { "contentId" : "3301681", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Mar 31, 2020 6:50 AM", "userId" : "3706612", "content" : "Hi User, sorry for the late, but i'm still waiting for the EVM. thanks for your understanding." }, { "contentId" : "3313043", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Apr 12, 2020 3:08 AM", "userId" : "3706612", "content" : "Hi User, i got the EVM, and will try the I2C. what is the status in your side?" }, { "contentId" : "3320752", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Apr 20, 2020 5:41 AM", "userId" : "3706612", "content" : "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." }, { "contentId" : "3320773", "userName" : "user6136286", "rankPoints" : "60", "rankName" : "Prodigy", "date" : "Apr 20, 2020 6:02 AM", "userId" : "6136286", "content" : "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?" }, { "contentId" : "3327910", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Apr 25, 2020 11:35 PM", "userId" : "3706612", "content" : "Hi Sorry, which question do you refer to?" }, { "contentId" : "3328187", "userName" : "user6136286", "rankPoints" : "60", "rankName" : "Prodigy", "date" : "Apr 27, 2020 12:57 AM", "userId" : "6136286", "content" : "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" }, { "contentId" : "3329899", "userName" : "Jasper Li", "rankPoints" : "37445", "rankName" : "Mastermind", "date" : "Apr 28, 2020 5:02 AM", "userId" : "3706612", "content" : "could you share the schematic? also share the VIN and VOUT waveform to show that your observation." } ], "tags" : [ "/support/power-management/f/196/tags/SM72442", "/support/power-management/f/196/tags/_2300_%2b%2b%2b%2b%2bI2C" ], "fourmType" : "TI" }