ZHCSP54 January 2022 DRV8316-Q1
PRODUCTION DATA
The power dissipated in the output FET resistance, or RDS(on) dominates power dissipation in the DRV8316-Q1.
At start-up and fault conditions, this current is much higher than normal running current; remember to take these peak currents and their duration into consideration.
The total device dissipation is the power dissipated in each of the three half-H-bridges added together.
The maximum amount of power that the device can dissipate depends on ambient temperature and heatsinking.
Note that RDS(on) increases with temperature, so as the device heats, the power dissipation increases. Take this into consideration when sizing the heatsink.
A summary of equations for calculating each loss is shown below for trapezoidal controland field-oriented control.
|
Loss type |
Trapezoidal |
Field-oriented control |
|---|---|---|
|
Standby power |
Pstandby = VM x IVM_TA | |
|
LDO (from VM) |
PLDO = (VM-VAVDD) x IAVDD, if BUCK_PS_DIS = 1b PLDO = (VBK-VAVDD) x IAVDD, if BUCK_PS_DIS = 0b |
|
|
FET conduction |
PCON = 2 x (IRMS(trap))2 x Rds,on(TA) | PCON = 3 x (IRMS(FOC))2 x Rds,on(TA) |
|
FET switching |
PSW = IPK(trap) x VPK(trap) x trise/fall x fPWM | PSW = 3 x IPK(FOC) x VPK(FOC) x trise/fall x fPWM |
|
Diode |
Pdiode = IPK(trap) x Vdiode x tdead x fPWM | Pdiode = 3 x IPK(FOC) x Vdiode x tdead x fPWM |
|
Demagnetization |
Without Active Demag: 3 x IPK(trap) x Vdiode x tcommutation x fmotor_elec With Active Demag: 3 x (IRMS(trap))2 x Rds,on(TA) x tcommutation x fmotor_elec |
Not Applicable |
|
Buck |
PBK = 0.11 x VBK x IBK (ηBK = 90%) | |