Datasheet

Power Dissipation
2-9
Test Setup and Results
2.4 Power Dissipation
The low junction-to-case thermal resistance of the PWP package with
PowerPad, along with a good board layout, allows the TPS54x80EVM-228
to provide full rated load current while maintaining safe junction temperatures.
The total board losses at 25°C are shown in Figure 2-9. The input voltage is
5 V. The load current shown in the Figure 2-3 is the sum of currents of both
core and I/O regulators.
The temperature rise of PowerPad, which is only few degrees below the
junction temperature, has been measured at 6 A (TPS54680/TPS54610) and
8 A (TPS54880/TPS54810) loads. At 6-A load current from each channel, the
temperature rise does not exceed 33°C and at 8 A the measured temperature
rise was 54.2°C. The overall dissipated power for these two conditions is 3.8
W and 7.2 W respectively. These test data are taken without airflow at room
temp 22°. For the additional information on the dissipation ratings of the
devices, see the individual product data sheets.
Figure 2-9. Measured Board Losses
0
1
2
3
4
5
6
7
8
9
10
0 2 4 6 8 10 12 14 16
Overall Power Loss - W
TPS54x80/TPS54x10
OVERALL POWER LOSS
(BOTH CHANNELS)
vs
OUTPUT CURRENT
I
O
- Output Current - A
V
I
= 5 V,
F
(SW)
= 700 kHz,
V
O1
= 1.8 V and V
O2
= 3.3 V