Design Converts User's Guide

SLUU161 – April, 2003
11
TPS40051-Based Design Converts 12-V Bus to 1.8 V at 15 A (SLUP195)
6 Test Results / Performance Data
6.1 Efficiency and Power Loss
Figure 3 shows the efficiency as the load is varied from 1 A to over 15 A. The typical efficiency remains over
90% as the load ranges from 3 A to 12 A.
Figure 3
0
88
78
2
86
80
90
94
4681012 14 16
82
84
92
I
OUT
– Output Current – A
Efficiency – %
EFFICIENCY
vs
LOAD
Figure 4
0
0
2
4
1
2
3
4 6 8 10121416
5
6
7
I
OUT
– Output Current – A
P
DISS
– Power Dissipation – W
POWER DISSIPATION
vs
LOAD
6.2 Closed Loop Performance
100 100 k10 k1 k
20
–30
10
–20
30
50
–10
0
40
100
0
80
20
120
160
40
60
140
f
OSC
– Oscillator Frequency – kHz
Gain – dB
Phase – °
OVERALL GAIN AND PHASE
vs
OSCILLATOR FREQUENCY
Gain
Phase
Figure 5.