Datasheet

SLUU194 − May 2004
9
Using the TPS51020
4.3 Efficiency and Power Loss
Figures 5 and 6 show the test efficiency and power losses vs. load current at different conditions. The maximum
efficiency is approximately 94.8% when both channels are enabled. The total power loss is 3.5 W when both
channels are on and deliverying 6.0 A.
0
82
80
1
23456
86
84
90
88
94
92
98
96
100
Figure 5.
I
OUT1,
I
OUT2
− Load Current − A
EFFICIENCY
vs
LOAD CURRENT
Efficiency − %
Channel 1 Enabled Only
Both
Channels
Enabled
Channel 2
Enabled Only
Figure 6.
0.5
0.0
1.0
2.0
1.5
2.5
3.0
3.5
01 2 3 45 6
P
DISS
− Power Loss − W
Channel 1
Enabled Only
Both
Channels
Enabled
Channel 2
Enabled Only
POWER LOSS
vs
LOAD CURRENT
I
OUT1,
I
OUT2
− Load Current − A
4.4 Output Ripple
In Figure 7 the output ripple waveform shows that two channels are running at 180º phase shift. The
peak-to-peak ripple voltage is less than 40 mV in each channel.
V
O2
20 mV/div
V
O1
20 mV/div
t − Time − 2.5 µs/div
I
OUT1
= 6 A
I
OUT2
= 6 A
V
IN
= 12 V
Figure 7. Output Ripple