Load Current (A)
Efficie
n
cy (%)
0
1
2
3
4
5
6
7
60
65
70
75
80
85
90
95
100
V
IN
= 8V
V
IN
= 12V
V
IN
= 18V
Test Setup and Procedure
10
SNVU623B – October 2018 – Revised April 2020
Copyright © 2018–2020, Texas Instruments Incorporated
LM5143-Q1 EVM User's Guide
5.4
Test Procedure
5.4.1
Line and Load Regulation, Efficiency
•
Set up the EVM as described above.
•
Set load to constant resistance or constant current mode and to sink 0 A.
•
Increase input source from 0 V to 12 V; use voltmeter 1 to measure the input voltage.
•
Increase the current limit of the input supply to 12 A.
•
Using voltmeter 2 to measure the output voltage, V
OUT1
, vary the load current from 0 A to 7 A DC; V
OUT1
must remain within the load regulation specification.
•
Using voltmeter 3 to measure the output voltage, V
OUT2
, vary the load current from 0 A to 7 A DC; V
OUT2
should remain within the load regulation specification.
•
Set the load currents to 3.5 A (50% rated load) and vary the input source voltage from 5.5 V to 36 V;
V
OUT1
and V
OUT2
must remain within the line regulation specification.
•
Decrease load to 0 A. Decrease input source voltage to 0 V.
6
Test Data and Performance Curves
through
present typical performance curves for the LM5143-Q1EVM-2100. Because
actual performance data can be affected by measurement techniques and environmental variables, these
curves are presented for reference and can differ from actual field measurements.
6.1
Conversion Efficiency
The curves with higher efficiency at light load correspond to when diode emulation is enabled (DEMB tied to AGND).
Figure 5. Dual-Channel Efficiency, V
IN
= 12 V, V
OUT1
= 3.3 V, V
OUT2
= 5 V
