Texas Instruments TPS40074EVM, Руководство пользователя

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4 Test Setup
4.1 Equipment
4.1.1 Voltage Source
V
12V_IN
The input voltage source (V
12V_IN
) should be a 0-V to 15-V variable DC source capable of 5 A
DC
. Connect
V
12V_IN
to J1 as shown in Figure 4-2 .
4.1.2 Meters
A1: 0 A
DC
5 A
DC
, ammeter
V1: V
12V_IN
, 0-Vto 15-V voltmeter
V2: V
1V5_OUT
0-V to 5-V voltmeter
4.1.3 Loads
LOAD1
The output load (LOAD1) should be an electronic constant current mode load capable of 0 A
DC
–15 A
DC
at 1.5 V.
4.1.4 Recommended Wire Gauge
V
12V_IN
to J1
The connection between the source voltage, V12V_IN, and J1 of HPA095 can carry as much as 3 A
DC
. The
minimum recommended wire size is AWG #16 with the total length of wire less than four feet (2-feet input, 2-feet
return).
J2 to LOAD1 (Power)
The power connection between J2 of HPA095 and LOAD1 can carry as much as 15 A
DC
. The minimum
recommended wire size is 2× AWG #16, with the total length of wire less than four feet (2-feet output, 2-feet
return).
J3 to LOAD1 (Remote Sense)
If remote sense is used, the remote sense connection between J3 of HPA095 and LOAD1 can carry less than 1
A
DC
. The minimum recommended wire size is AWG #22, with the total length of wire less and four feet (2-feet
output, 2-feet return).
4.1.5 Other
FAN
This evaluation module includes components that can get hot to the touch, because this EVM is not enclosed
to allow probing of circuit nodes, a small fan capable of 200–400 lfm is required to reduce component surface
temperatures to prevent user injury. The EVM should not be left unattended while powered or probed while the
fan is not running.
OSCILLOSCOPE
A 60-MHz or faster oscilloscope can be used to determine the ripple voltage on 1V5_OUT. The oscilloscope
should be set for the following to take output ripple measurements:
• 1-MΩ impedance
• AC coupling
• 1-μs/division horizontal resolution
• 20-mV/division vertical resolution
TP15 and TP16 can be used to measure the output ripple voltage by placing the oscilloscope probe tip through
TP15 and holding the ground barrel to TP16 as shown in
Figure 4-2 . For a hands-free approach, the loop in
TP16 can be cut and opened to cradle the probe barrel. Using a leaded ground connection can induce additional
noise due to the large ground loop area.
Test Setup www.ti.com
6 TPS40074 Buck Controller Evaluation Module User's Guide SLUU231A – JUNE 2006 – REVISED JANUARY 2022
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