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2.5
Efficiency
0
10
20
30
40
50
60
70
80
90
100
0.001
0.01
0.1
1
10
I
- Output Current - A
O
3
3.6
4.2
5
Efficiency-%
TPS63000,
PS = Low,
V
= 3.3 V
O
2.6
Power Dissipation
2.7
Load Transients
LOAD I
VOUT 100 mV/div
Setup and Results
Efficiency of over 90% is common at mid-to-high loads. With power-save mode enabled, efficiency is
greater than 80% at light loads of 1 mA to 100 mA.
Figure 4. Efficiency Over Li-Ion Cell Range
With high efficiency, the power to be dissipated is low. Also, the QFN package with a solder pad is very
efficient at removing heat. In this case, with unit delivering 3.3 V at 550 mA and 90% efficiency, power
dissipation will be 180 mW. The package thermal resistance is about 50
°
C/W, therefore the
case-to-junction temperature rise would be 9
°
C. This would allow an ambient temperatire of 116
°
C, and
still hold the junction temperature below 125
°
C.
Load transient response is well regulated. Additional output capacitance reduces voltage over- and
under-shoot.
Figure 5. Load Step 100 mA to 500 mA
SLVU156 – March 2006
TPS63000EVM-148
5