Other Parts Discussed in Thread: BQ25798, BQ25792
Tool/software:
Hello,
We are interested in the BQ25672 charger, for charging 2S and 3S Lithium batteries.
We have seen that the internal structure and the electrical parameters are almost identical to the BQ25792 and BQ25798:
| BQ25672 | BQ25792 | BQ25798 | |
| RSNS | 8 mΩ | 6 mΩ | 8 mΩ |
| Q1 | 24 mΩ | 24 mΩ | 24 mΩ |
| Q2 | 35 mΩ | 35 mΩ | 35 mΩ |
| Q3 | 28 mΩ | 28 mΩ | 28 mΩ |
| Q4 | 17 mΩ | 17 mΩ | 17 mΩ |
| BATFET | 11 mΩ | 8 mΩ | 11 mΩ |
Other differences that we have seen are that the BQ25798 has "MPTT" and "Backup mode", and that the BQ25672 doesn't seem to have the same USB capabilities as the other two.
We have a few doubts:
- Why is BQ25672 rated current 3A, but BQ25792/8 is 5A? Are there any thermal differences between them?
- Does the BQ25672 work in Buck mode only? It has the same MOSFET structure for Buck-Boost operation as BQ25792/8.
- Is there a way to bypass Q4 if we only need to work in Buck mode (Vbus > Vbat)? Connecting one end of the inductor to SYS instead of SW2?
- Are there any other major difference between the 3 devices?
Thanks a lot!
