21/39

AN1625 APPLICATION NOTE

Figure 21. Maximum output current vs. selectable devices.

2.13.2 Power Dissipation Formulae

Figure 22 to Figure 25 are screenshots of a spreadsheet that helps calculating power dissipation in specified

conditions (application and motor data), and estimates the resulting junction temperature for a given package

and copper area available on the PCB [3].

The model considers power dissipation during the on-time and the off-time, taking into account the selected de-

cay, rise and fall time (when a phase change occurs), the switching losses and the quiescent current power dis-

sipation.

0.50

0.70

0.90

1.10

1.30

1.50

1.70

1.90

2.10

2.30

Load Current

[A]