DRV8432: DRV8432 thermal calculation

hello, i have a question about the DRV8432 thermal calculation

the spec of DRV8432 shows it can output 2*7A continous and 2*12A peak.

but when i do the thermal calculation i found if i output 2*7A current, the Tj will be 311℃ which exceed a lot from the maximum Tj 150℃

below is the calculation of the thermal

• Tj= Ta+RθjA*Pd
• Pd=Imax^2*（Rds(on)high+ Rds(on)low）*2
• Imax=7A
• Rds(on)high=Rds(on)low=0.11Ω
• RθjA=13.3℃/W
• Ta=25℃
• Tj=25+13.3*21.56=311℃

if we want to keep the Tj below 150℃,and use two full bridge drive two BDC motor, the maximum current should not exceed 2*4.6A, this is miss match the output current with 2*7A

could you help me to answer my confuse and give me some advise about is it possible to use this IC to output 2*6.2A continous current

thanks a lot