LP8863EVM Board Stackup
17
SNVU558 – February 2017
Copyright © 2017, Texas Instruments Incorporated
The LP8863EVM Evaluation Module
The LP8863EVM must be modified to support standalone mode from its default settings described as
follows:
1. Remove jumper on J19.
2. Connect pin 3 and 4 of J14 to connect V
LDO
output from LP8863-Q1 to VDDIO input.
3. Mount R68 to pull up PWM input for 100% brightness. If brightness needs to be changed from 100%,
connect external PWM source here (SDO_PWM).
4. Mount R63 to select I
2
C interface, so PWM input pin is not assigned to SDO of SPI interface.
5. Mount R64 to pull up EN input.
6. Change pullup and pulldown resistors to select spread spectrum enable (R66) or disable (R71) option.
The minimum procedures for turning on the LEDs after modifications above are as follows:
•
Connect external power (VBAT, 3 V to 48 V; typical 12 V, 6 A) and ground to the board (recommended
boost conversion ratio less than 10).
•
Connect LED load board (6 strings, 8 LEDs per string) to J33 (use caution about the boost output pin
location).
•
Enable external power supply.
6
LP8863EVM Board Stackup
Figure 10. LP8863EVM Board Stackup