Texas Instruments Evaluation Module for TPS7A7100 Low-Dropout Linear Regulator TPS7A7100EVM-718 TPS7A7100EVM-718 Datenbogen
Produktcode
TPS7A7100EVM-718
Operation
2.2
Soldering Guidelines
Any solder rework to modify the EVM for the purpose of repair or other application reasons must be
performed using a hot-air system to avoid damaging the integrated circuit IC especially.
performed using a hot-air system to avoid damaging the integrated circuit IC especially.
2.3
Initial Setup and Equipment Interconnect
•
VOUT Select. Program the desired output voltage per instruction 2.1, bullet J5. Use the shorting
jumpers provided with the EVM to jumper the header pins. Note that the EVM is preset for VOUT equal
to 1.8 V. The jumper across J5 pins 13 to 14 is no-connect and unused.
jumpers provided with the EVM to jumper the header pins. Note that the EVM is preset for VOUT equal
to 1.8 V. The jumper across J5 pins 13 to 14 is no-connect and unused.
•
Disable the EVM. Add a shorting jumper to JP1 from EN (pin 2) to OFF (pin3)
•
Input Power Supply connection. Before connecting the input power supply to the EVM, verify that its
output voltage is set to the desired supply voltage (less than 6.5 V) and that its current limit is set to
approximately 4 A. Now turn off the power supply. Connect the positive voltage lead (+) from input
power supply to VIN (J4, pin 1) of the EVM. Connect the ground lead (–) from the input power supply
to GND (J4, pin 2). Note that for the recommended best thermal and ac performance, ensure that the
input voltage at TP4 is 0.5 V to 1 V above VOUT.
output voltage is set to the desired supply voltage (less than 6.5 V) and that its current limit is set to
approximately 4 A. Now turn off the power supply. Connect the positive voltage lead (+) from input
power supply to VIN (J4, pin 1) of the EVM. Connect the ground lead (–) from the input power supply
to GND (J4, pin 2). Note that for the recommended best thermal and ac performance, ensure that the
input voltage at TP4 is 0.5 V to 1 V above VOUT.
•
Connect a 0-A to 2-A load between VOUT (J3, pin 1) and GND (J3, pin 2).
3
Operation
•
Turn on the input power supply. Verify that the output voltage, VOUT, is near 0 V.
•
Enable the output by reconnecting the jumper on JP1 to short the EN (pin 2) to the ON (pin 1).
•
Vary the load current and VIN voltage as necessary for test purposes.
Note that power dissipation (P
disp
) across the TPS7A7X00 itself depends on the VIN-to-VOUT
voltage drop and the output load current, I
Load
(P
disp
= (VIN – VOUT)×I
Load
). If the power dissipation is
high, then the customer may see the output voltage transitioning on-off-on due to the shutdown
effect of the thermal-limit shutdown circuit.
effect of the thermal-limit shutdown circuit.
4
Test Results
This section provides typical performance waveforms for the TPS7A4001EVM-709 characteristic of this
EVM design.
EVM design.
4.1
Turnon Characteristic
shows the VOUT ramp-up waveform at turnon (ENable) as well as the input surge current into
the IN pin of the LDO itself when the LDO starts up into a fully loaded output.
3
SLAU430 – February 2012
TPS7A7x00EVM-718 Evaluation Module
Copyright © 2012, Texas Instruments Incorporated