Texas Instruments TPS40075EVM, Руководство пользователя

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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.
4.2 Equipment Setup
Figure 4-2 shows the basic test setup recommended to evaluate the TPS40075EVM-001. Note that although the
return for J1 and J2 are the same, the connections should remain separate as shown in Figure 4-1 .
4.2.1 Procedure
1. Working at an ESD workstation, make sure that any wrist straps, bootstraps, or mats are connected
referencing the user to earth ground before power is applied to the EVM. An electrostatic smock and safety
glasses should also be worn.
2. Prior to connecting the DC input source, V
12V_IN
, it is advisable to limit the source current from V
12V_IN
to
5.0-A maximum. Make sure V
12V_IN
is initially set to 0 V and connected as shown in Figure 4-1 .
3. Connect the ammeter A1 (0-A to 5-A range) between V
12V_IN
and J1 as shown in Figure 4-1 .
4. Connect voltmeter V1 to TP1 and TP2 as shown in Figure 4-1 .
5. Connect LOAD1 to J2 as shown in Figure 3-1 . Set LOAD1 to constant current mode to sink 0 A
DC
before
V
12V_IN
is applied.
6. Connect voltmeter, V2 across TP17 and TP18 as shown in Figure 4-1 .
7. Connect an oscilloscope probe to TP16 and TP15 as shown in Figure 4-2 .
8. Place a fan as shown in Figure 4-1 . Turn it on, making sure air is flowing across the EVM.
4.2.2 Diagram
See Tip and Barrel
Measurement for V
OUT
Ripple
UDG−06084
LOAD 1
1.5V @
15 A
−
+
−
+
V1
FAN
−1
V
5
_
O
U
T
+
+ 12 V_IN −
+
−
Oscilloscope
+
+
−
−
A1
−
+
TP1 TP2
TP16
TP15
TP5 TP7 TP6
J2
J1
V2
+
−
−
+
TP18
TP17
GND CHA CHB
TP21
TP19
TP20
Shutdown
V
12V_IN
TEXAS INSTRUMENTS
TPS40075EVM−001
12V to 1.5V @ 15A with Remote Sense
HPA187
1MW AC
10mV/div
20MHz
Figure 4-1. TPS40075EVM-001 Recommended Test Setup
www.ti.com Test Setup
SLUU254A – DECEMBER 2006 – REVISED JANUARY 2022
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