Texas Instruments TPS7B4254-Q1, Руководство пользователя

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OUT FB ADJ
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R R
V 1 V 1 V
R R
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Setup
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2 SLVUAT0 – June 2016
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Copyright © 2016, Texas Instruments Incorporated
TPS7B4254-Q1 Evaluation Module
2 Setup
This section describes the jumpers and connectors on the EVM as well as how to properly connect, set
up, and use the TPS7B4254-Q1 EVM.
2.1 Input and Output (I/O) Connector Descriptions
TP1/VIN – This test point provides a power (VIN) connection for powering the EVM. The input voltage can
be measured on this test point.
TP2/ADJ – This test point is a reference input voltage for the regulator, allowing the user to attach a
reference voltage to the EVM and measure the input voltage of ADJ pin.
TP3/VOUT – This test point provides the output of the regulator allowing attachment of a load to the EVM.
The output voltage can be measured on this test point.
TP4/TP5/TP6/GND – GND is the ground return for the regulator. The EVM provides three GND test points
to power up the EVM, to connect the load, and to attach an oscilloscope ground lead.
TP7/FB – This test point is the feedback for the regulator allowing measurement of the voltage of the FB
pin.
J1/J2/Output voltage selection – These two connectors provide the choice of two different output
voltage modes:
1. VOUT equals ADJ (default) : Connect pin 1 and 2 of J1, and leave J2 open. This connection sets the
output voltage equal to ADJ with high accuracy.
2. VOUT decided by resistor : Connect pin 1 and 2 of J2, and leave J1 open. This connection sets the
output voltage with Equation 1 . Output voltage can be modified by changing resistors R1 and R2. With
the EVM default setup, output voltage should be 40 V when the reference input voltage ADJ is 5 V.
(1)
2.2 Bench Setup
The input voltage range for the tracking LDO TPS7B4254-Q1 is 4 V to 40 V. The EVM can support up to
150 mA of load current. Using the following steps to setup the test bench for the EVM:
1. Set the power supply for input VIN to 12 V and set current limit to 1.2 A.
2. Set the power supply for reference ADJ to 5 V and set current limit to 0.1 A.
3. Connect the input power supply positive lead to VIN and the negative lead to GND.
4. Connect the reference power supply positive lead to ADJ and the negative lead to GND.
5. Apply the load between VOUT and GND.
2.3 Operation
The TPS7B4254-Q1 powers up after the VIN voltage exceeds the UVLO rising threshold.