Other Parts Discussed in Thread: BQ24251, BQ25606
I need to charge a single lithium ion battery. I selected the BQ24253 because it supports both USB through D+ and D- detection and EN1 and EN2 detection. I have been reading through the threads on the BQ2425X and I am not sure I should be using this chip. The data sheet says the BQ24251 is NRND, but makes no mention why and says nothing about the BQ24253. I looked on the product page for the BQ24253 and it says it is active. I don't need to communicate with a microprocessor so a stand alone chip like the BQ24253 is fine.
I need to be able to use both a USB power port and a 9V 2A wall mount power supply.
The BQ24253 says the following:
"During power up, the device checks first for the D+/D-. The EN1 and EN2 do not take effect until
D+/D- detection routine is over and a change on the status of the EN1 and EN2 occurred."
Which is an incredibly vague statement. How long does the D+/D- detection take? What change has to happen for the EN1 or EN2 status? I can't find anywhere in the data sheet the time required for the D+/D- detection. I am assuming I need to delay the EN2 transition from low to high until after the state machine has looked for the D+/D1.
Any help on using this device would be greatly appreciated. Is the BQ24253 supported in WEBBENCH?
