data/json/DLP/891226.json

{
  "ticketNumber" : "891226",
  "reporterName" : "James Zhan",
  "rankPoints" : "1755",
  "resolutionStatus" : "TI Thinks Resolved",
  "ticketName" : "BQ24773: BATPRES PIN connection",
  "rankName" : "Intellectual",
  "replies" : " 2",
  "views" : " 28",
  "queryText" : "Part Number: BQ24773 Hi team, According to the datasheet, the PIN 15 of BQ24773 \"BATPRES\" is input signal PIN, but in the EVM I've found it seems to be output PIN. If customer want to connect this pin to the MCU to indicate whether if the battery is present, how should they do? Thanks.",
  "partNumber" : " BQ24773",
  "allResponseList" : [ {
    "contentId" : "3295447",
    "userName" : "Steve Preissig",
    "rankPoints" : "4610",
    "rankName" : "Expert",
    "date" : "Mar 24, 2020 1:53 PM",
    "userId" : "8914",
    "content" : "Hello James, The /BATPRES signal on BQ2477x is always an input signal. The reason that it behaves like an output signal on the EVM is because there is an external comparator (U2) that generates a /BATPRES signal from the battery voltage. If the battery pack your customer is using does not have a signal that can be connected to the MCU for this purpose, then an external comparator such as used on the EVM can be used. Note that the BQ2477x also has an independent comparator that can be used to detect battery presence as well. You can refer to the BQ24780s EVM for an example of how the independent comparator can be used instead of an external comparator, saving cost and board space. (BQ24780s EVM has an external comparator as well, but there are jumper options to select between using the external comparator or independent comparator for /BATPRES) Regards, Steve"
  }, {
    "contentId" : "3323912",
    "userName" : "James Zhan",
    "rankPoints" : "1755",
    "rankName" : "Intellectual",
    "date" : "Apr 22, 2020 7:27 AM",
    "userId" : "5039519",
    "content" : "Hi Steve, Thanks for the comments. I have more questions as below: 1. Is PIN 15 BATPRES the only way to detect if battery present in BQ24773? could we just read one of the register and get this information? 2. Could we left BATPRES PIN open, not connecting to anything? Would this has any risk? Please let me know if you have any ideas, thanks!"
  } ],
  "tags" : [ "/support/power-management/f/196/tags/BQ24773" ],
  "fourmType" : "TI"
}