Texas Instruments TPS54290, Руководство пользователя

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4 Test Setup
4.1 Equipment
4.1.1 Voltage Source (V
IN
)
The input voltage source (V
IN
) should be a 0-V to 15-V variable DC source capable of 2-A DC. Connect V
IN
to J1
as shown in Figure 4-2 .
4.1.2 Meters
• A1: 0-Adc to 2-Adc ammeter
• V1: VIN, 0-V to 15-V voltmeter
• V2: VOUT1, 0-V to 6-V voltmeter
• V3: VOUT2, 0-V to 4-V voltmeter
4.1.3 Loads
LOAD1
The Output1 Load (LOAD1) should be an electronic constant current mode load capable of 0 Adc to 1.5 Adc at
3.3 V.
LOAD2
The Output2 Load (LOAD2) should be an electronic constant current mode load capable of 0 Adc to 2.5 Adc at
1.2 V.
4.1.4 Oscilloscope
A Digital or Analog Oscilloscope can be used to measure the ripple voltage on VOUT1 or VOUT2. The
oscilloscope should be set for the following for taking output ripple measurements:
• 1-MΩ impedance
• 20-MHz Bandwidth
• AC coupling
• 1-μs/division horizontal resolution
• 10-mV/division vertical resolution
TP3 and TP4 or TP18 and TP19 can be used to measure the output ripple voltages by placing the oscilloscope
probe tip through TP3 or TP18 and holding the ground barrel to TP4 or TP19 as shown in
Figure 4-2 . For a
hands free approach, the loop in TP4 or TP19 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.
4.1.5 Recommended Wire Gauge
V
IN
to J1
The connection between the source voltage, VIN, and J1 of HPA431 can carry as much as 5 Adc. The minimum
recommended wire size is AWG #16 with the total length of wire less than four feet (two feet input, two feet
return).
J2 to LOAD1
The power connection between J2 of HPA431 and LOAD1 can carry as much as 1.5 Adc. The minimum
recommended wire size is AWG #18 with the total length of wire less than two feet (two foot output, two foot
return).
J3 to LOAD2
The power connection between J3 of HPA431 and LOAD2 can carry as much as 2.5 Adc. The minimum
recommended wire size is AWG #18 with the total length of wire less than 2two feet (one foot output, one foot
return).
4.1.6 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 200lfm to 400 lfm is recommended to reduce component
surface temperatures to prevent user injury. The EVM should not be left unattended while powered. The EVM
should not be probed while the fan is not running.
www.ti.com Test Setup
SLVU356A – JANUARY 2010 – REVISED OCTOBER 2021
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TPS54291 Step-Down Converter Evaluation Module User's Guide 7
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