Texas Instruments 10A, 12V Input, 1.8V Output Synchronous Buck Converter using the TPS40192 and NexFET MOSFETs TPS40192E TPS40192EVM-525 Datenbogen
Produktcode
TPS40192EVM-525
Test Setup
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4.1.4
Oscilloscope
A digital or analog oscilloscope can be used to measure the ripple voltage on V
OUT
. The oscilloscope
should be set for 1-M
Ω
impedance, 20-MHz bandwidth, AC coupling, 1-
μ
s/division horizontal resolution,
10-mV/division vertical resolution for taking output ripple measurements. 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
measure the output ripple voltage by placing the oscilloscope probe tip through TP15 and holding the
ground barrel to TP16 as shown in
. For a hands-free approach, the loop in TP16 can be cut and
opened to cradle the probe barrel. Using a leaded ground connection may induce additional noise due to
the large ground loop area.
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 HPA525 can carry as much as 5 Adc. The
minimum recommended wire size is AWG #16 with the total length of wire less than 4 feet (2 feet input, 2
feet return). J2 to LOAD1 (power)
minimum recommended wire size is AWG #16 with the total length of wire less than 4 feet (2 feet input, 2
feet return). J2 to LOAD1 (power)
The power connection between J2 of HPA525 and LOAD1 can carry as much as 10 Adc. The minimum
recommended wire size is 2x AWG #16, with the total length of wire less than 2 feet (1 feet output, 1 feet
return).
recommended wire size is 2x AWG #16, with the total length of wire less than 2 feet (1 feet output, 1 feet
return).
4.1.6
Other
This evaluation module includes components that can become 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 if
powered. The EVM should not be probed if the fan is not running.
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 if
powered. The EVM should not be probed if the fan is not running.
4.2
Equipment Setup
Shown in
is the basic test setup recommended to evaluate the TPS40192EVM-525. Note that
although the return for J1 and J2 are the same, the connections should remain separate as shown in
4.2.1
Procedure
1. When working at an ESD workstation, ensure that any wrist straps, bootstraps, or mats are connected
referencing the user to earth ground before power is applied to the EVM. Electrostatic smock and
safety glasses also should be worn.
safety glasses also should be worn.
2. Prior to connecting the DC input source, V
IN
, it is advisable to limit the source current from VIN to 5 A
maximum. Ensure that V
IN
is initially set to 0 V and connected as shown in
.
3. Connect the ammeter A1 (0- to 5-A range) between V
IN
and J1 as shown in
.
4. Connect voltmeter V1 to TP1 and TP2 as shown in
5. Connect LOAD1 to J2 as shown in
. Set LOAD1 to constant-current mode to sink 0 Adc before
V
IN
is applied.
6. Connect voltmeter, V2 across TP15 and TP16 as shown in
.
7. Place fan as shown in
and turn on, ensuring that air is flowing across the EVM.
8
Using the TPS40192EVM-525, A 12-V Input, 1.8-V Output, 10-A Synchronous
SLUU395 – December 2009
Buck Converter
Copyright © 2009, Texas Instruments Incorporated