We have built a Li-ion charger circuit using the bq24600 with a circuit similar to the bq24600 EVM, but physically a little smaller. This battery pack consists of 6 x 3000mAh cells in series (max constant voltage charge of 25.2V ), and the charger has an input supply of 28V.
The coil switching FETs from the EVM (SiR4260DP) are not stocked at present.
We have tried several alternative FETs with similar performance characteristics, but have not found one that works as well as the SiR426DP.
We either get too much ringing on the high side FET or both the FET and bq24600 run very hot (or both). The best we have found so far is the SI7172ADP-T1-RE3 which gives clean switching but causes both the FET and bq24600 to run hot even at 3 amps charge. Using the SiR4260DP FETs from the evaluation board in our circuit works well – no ringing and much cooler operation. Can anyone recommend a currently available FET with a similar footprint that performs as well as the SiR4260DP ?
