Texas Instruments LP877451Q1EVM, User Manual

4 Getting Started

In its default configuration, conn12 V and GND to the VBAT terminal block (J35) will power up the EVM. 
While loading the regulators, ensure that input power supply has sufficient current source capabilities to avoid 
supply voltage collapse due to current limiting.

EVM can also be powered through external 3.3 V input supply or through USB power by modifying jumper 
settings on the EVM. 

Table 4-1

 describes the jumper settings for different supply options.

Table 4-1. Jumper Connections for Powering the EVM

Power Source

Input Voltage Range

Jumpers

VBAT

5 V - 20 V

Both 3V3_PREREG jumpers in J9 (Default option)

Vin 3.3V

3.1 V - 3.5 V

Remove 3V3_PREREG jumpers on J9 and place 
them on 3V3_PS position on J9. With this 
configuration, do not apply power to VBAT terminal

USB

5 V USB cable

J11, 3V3_USB. With this option, jumpers on J9 must 
be removed.

The LP877451Q1EVM does not require any specific power-down sequence. The EVM can be powered down 
by turning off the power supply or by toggling the EN Pin off in the GUI, if the GUI control signal is used to 
enable/disable the device. Refer to 

Table 3-2

 and 

GUI section

 for more information about configuring jumpers 

and using GUI.

4.1 GUI

Texas Instruments provides a simple to use LP87745-Q1 GUI tool to enable, configure, and evaluate the various 
features of the LP87745-Q1 device on the EVM. Please refer to the GUI 

README.md

 file in the GUI tool's 

Help->View README.md

 tab for a more detailed description of this tool.

The GUI will run on most PC platforms and requires a USB port for connecting the EVM to the host computer. 
The EVM USB connector is type-C and a type-A to type-C cable is provided along with the EVM to connect 
to the host computer. EVM will get automatically connected to the GUI after the USB cable is connected and 
manual assignment of COM port is not necessary. If 

Hardware not Connected

 displays on the bottom left of 

the GUI, clicking 

Click to connect to hardware

 icon next to it will re-establish the connection. The GUI uses the 

ACCtrl COM port which can be found from the device manager of the operating system.

4.2 GUI Installation and working with GUI

The GUI can be found 

here

 and it can be run in browser or it can be installed to the computer. Please refer to the 

README.md

 file in the GUI tool for a complete guide on how to use the tool.

www.ti.com

Getting Started

SNVU769 – SEPTEMBER 2021

Submit Document Feedback

LP877451Q1EVM Evaluation Module

7

Copyright © 2021 Texas Instruments Incorporated