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EVM Setup

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SBVU048 – March 2019

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TPS7A78EVM-011 Evaluation module

5

EVM Setup

This section describes how to properly connect and setup the TPS7A78EVM-011, including the jumpers
and connectors on the EVM board. See

Section 6

for the proper connections of test equipment.

5.1

Input/Output Connectors and Jumpers Descriptions

5.1.1

J1: V

AC

Input AC power-supply connector. Ensure that the AC input power supply is turned off before making the
connection to the EVM. The AC supply line lead must be connected to the line pin on the J1 connector,
whereas the neutral lead must be connected to the neutral pin on the J1 connector to ensure proper
operation of the TPS7A78 LDO.

NOTE:

If the AC supply line and neutral leads are flipped when connected to the J1 connector, then

the TPS7A78 device GND pin is referenced to the AC supply line and only floating
measurement equipment must be used.

5.1.2

J3: Full-Bridge (FB) and Half-Bridge (HB) Configurations

This EVM comes configured for half-bridge (HB) configuration usage, when J3 jumper is connected.
However, to use the full-bridge (FB) configuration, leave jumper J3 open and see

Section 6

for the proper

connections of test equipment.

HB configuration is achieved by tying V

AC

neutral to the TPS7A78 device GND pin, whereas in FB

configuration V

AC

neutral is connected to the AC– pin and the device GND pin track V

AC

neutral and

therefore must be floating. See

Section 6

for the proper connections of test equipment.

NOTE:

When FB configuration is used, the device GND must float (that is, the device GND must not

be tied to Earth-GND). Floating the device GND is required to limit the shunted AC current
(the excess AC current charging the bulk capacitor C8) while the device active bridge shunts
this current to circulate this current back to neutral. Jumper J5 is open by default to limit the
circulating current though neutral when the device GND is intentionally or accidentally
connected to Earth-GND, such as when using regular scope probes or a bench digital
multimeter (DMM) where such equipment have their GNDs always tied to Earth-GND. Use
floating measurement equipment when the FB EVM configuration is used.

5.1.3

J4: Power-Good Indication and Power-Fail Detection Pullup Voltage

Jumper J4 pulls up the open-drain power-good and power-fail detection indicators to V

LDO_IN

by athe

default EVM setting. An external DC pullup voltage can be used via test point TP11; however, jumper J4
must be open in order not to short the external pullup voltage to the LDO_IN pin.

NOTE:

When an external DC voltage is used to pullup the PG and PF pins, this external supply

must be a floating supply when FB configuration is used.

For HB configuration, the device GND can be tied to Earth-GND, and the external pullup
supply can be referenced to the device GND.

5.1.4

J5: Second Surge Resistor (R7) Jumper

This EVM has three surge resistors, R5, R6, and R7. However, only one resistor R5 is required. R7 is
needed when the device GND is tied to Earth-GND intentionally or accidentally when using regular scope
probes.

R6 was populated for test purposes only. Capacitor C21 is a placeholder for conducting electromagnetic
interference (EMI) filtering.

Summary of Contents for TPS7A78EVM-011

Page 1: ...tion of the TPS7A78 non isolated smart linear voltage regulator LDO Included in this user s guide are setup and operating instructions thermal and layout guidelines a printed circuit board PCB layout...

Page 2: ...he FB EVM Configuration 9 8 Proper Test Equipment Connections for the Half Bridge HB EVM Configuration 10 9 Assembly Layer 11 10 Top Layer Routing 11 11 Bottom Layer Routing 12 List of Tables 1 Relate...

Page 3: ...a development environment exceeding 50Vrms 75VDC must be electrically located within a protected Emergency Power Off EPO protected power strip e Use stable and nonconductive work surface f Use adequat...

Page 4: ...You Begin This evaluation module is not encapsulated and has exposed terminals with voltages that are connected to the main AC supply the following warnings are noted for the safety of anyone using o...

Page 5: ...ed TPS7A78EVM 011 Evaluation module 3 Electrical Performance Specifications Table 2 lists the electrical specifications for the TPS7A78EVM 011 evaluation board 1 All measurements are done with a half...

Page 6: ...test equipment NOTE When FB configuration is used the device GND must float that is the device GND must not be tied to Earth GND Floating the device GND is required to limit the shunted AC current the...

Page 7: ...ee PG and PF signals 5 1 6 J2 VLDO_OUT Regulated DC output voltage connector NOTE This EVM is optimized for a 3 3 V output and a 27 mA to 55 mA max load current If your application requires higher out...

Page 8: ...C VPG EVM Setup www ti com 8 SBVU048 March 2019 Submit Documentation Feedback Copyright 2019 Texas Instruments Incorporated TPS7A78EVM 011 Evaluation module 5 3 1 Startup Figure 2 to Figure 5 show var...

Page 9: ...19 Submit Documentation Feedback Copyright 2019 Texas Instruments Incorporated TPS7A78EVM 011 Evaluation module 5 4 Soldering Guidelines To avoid damaging the LDO use a hot air system for any solder r...

Page 10: ...8EVM 011 Evaluation module 6 1 2 Half Bridge HB Test Equipment Connection Figure 8 shows an HB connection diagram Figure 8 Proper Test Equipment Connections for the Half Bridge HB EVM Configuration To...

Page 11: ...Copyright 2019 Texas Instruments Incorporated TPS7A78EVM 011 Evaluation module 7 PCB Layout Figure 9 to Figure 11 illustrate the PCB layout for this EVM Figure 9 Assembly Layer NOTE The silk screens f...

Page 12: ...PCB Layout www ti com 12 SBVU048 March 2019 Submit Documentation Feedback Copyright 2019 Texas Instruments Incorporated TPS7A78EVM 011 Evaluation module Figure 11 Bottom Layer Routing...

Page 13: ...F 20 35V T H TH 35ZLQ120MEFC6 3X11 Rubycon C11 1 10 F CAP CERM 10 F 25 V 10 X7R 1206 1206 C3216X7R1E106K160AB TDK C15 1 0 47 uF CAP Film 0 47 uF 1000 V 20 TH TH PHE844RD6470MR30L2 Kemet C18 1 1 uF CAP...

Page 14: ...ther than TI b the nonconformity resulted from User s design specifications or instructions for such EVMs or improper system design or c User has not paid on time Testing and other quality control tec...

Page 15: ...These limits are designed to provide reasonable protection against harmful interference in a residential installation This equipment generates uses and can radiate radio frequency energy and if not in...

Page 16: ...instructions set forth by Radio Law of Japan which includes but is not limited to the instructions below with respect to EVMs which for the avoidance of doubt are stated strictly for convenience and s...

Page 17: ...any interfaces electronic and or mechanical between the EVM and any human body are designed with suitable isolation and means to safely limit accessible leakage currents to minimize the risk of electr...

Page 18: ...R DAMAGES ARE CLAIMED THE EXISTENCE OF MORE THAN ONE CLAIM SHALL NOT ENLARGE OR EXTEND THIS LIMIT 9 Return Policy Except as otherwise provided TI does not offer any refunds returns or exchanges Furthe...

Page 19: ...e resources are subject to change without notice TI grants you permission to use these resources only for development of an application that uses the TI products described in the resource Other reprod...

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