SLUU131A – September 2002 – Revised February 2003
12
TPS40001 Based Converter Delivers 10-A Output
Typical efficiency curves are shown in Figure 5 for 3.3-V input. It should be stressed that measuring high
efficiencies requires the utmost care in instrumentation. The power losses are so low that small errors can lead
to large variations in measured efficiency. The input and output voltages are measured on the PCB as shown
in the test diagram to avoid the losses associated with the input and output connectors.
Efficiency
–
%
EFFICIENCY
vs
OUTPUT CURRENT
IOUT – Output Current – A
50
55
60
65
70
75
80
85
90
95
100
0.00
2.00
6.00
8.00
10.00
4.00
Figure 5.
Figure 6 shows the switch node at V
IN
= 5 V and I
OUT
=10 A. As the picture indicates, there is almost negligible
body diode conduction using the Predictive Gate Drive
t
technique.
t – Time – 500 ns/div
2 V/div
TYPICAL SWITCH NODE WAVEFORM
Figure 6.
