The power dissipation of the device can be estimated by adding the power dissipation of each regulator. The power dissipation of each regulator can be estimated based on the measured efficiency of each regulator. The measured efficiency of
the regulator consists of device power losses and inductor power losses. To estimate the power dissipation within the device, the power dissipation of the inductor should be subtracted from the total regulator power dissipation that is
calculated based on the efficiency measurement.
Use Equation 16 to estimate the total
regulator power dissipation for the BUCK1 regulator, BUCK2 regulator, and BOOST
converter.
Equation 16.
where
- PD(tot) is the total power dissipation of the BUCK1 regulator, BUCK2 regulator, or BOOST converter including inductor power dissipation.
- VOUT is the output voltage of the regulator.
- IOUT is the output current of the regulator.
- η is the efficiency of the regulator based on measurement results.
Use Equation 17 to calculate the
internal power dissipation of the BUCK1 regulator.
Equation 17.
where
- PD(BUCK1) is the internal power dissipation of the device because of the BUCK1 regulator.
- PD(BUCK1_tot) is the total power dissipation of the BUCK1 regulator including inductor power dissipation.
- LDCR_BUCK1 is the series resistance of the inductor as specified in the data sheet of the BUCK1 inductor.
Use Equation 18 to calculate the
internal power dissipation of the BUCK2 regulator.
Equation 18.
where
- PD(BUCK2) is the internal power dissipation of the device because of the BUCK2 regulator.
- PD(BUCK2_tot) is the total power dissipation of the BUCK2 regulator including inductor power dissipation.
- LDCR_BUCK2 is the series resistance of the inductor as specified in the data sheet of the BUCK2 inductor.
Use Equation 19 to calculate the
internal power dissipation of the device because of the BOOST
converter.
Equation 19.
where
- PD(BOOST) is the internal power dissipation of the device because of the BOOST converter.
- PD(BOOST_tot) is the total power dissipation of the BOOST converter including inductor power dissipation.
- IIN_BOOST is the input current of the BOOST converter (see Equation 14).
- LDCR_BOOST is the series resistance of the inductor as specified in the data sheet of the BOOST inductor.
Use Equation 20 to calculate the total
internal power dissipation of the device.
Equation 20.
where
- PD(DEVICE) is the total internal power dissipation of the device.