Setup
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SNVU558 – February 2017
Copyright © 2017, Texas Instruments Incorporated
The LP8863EVM Evaluation Module
Figure 2. LP8863-Q1 Evaluation Board (Bottom View)
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Setup
This section describes the jumpers and connectors on the EVM as well as how to properly connect and
setup to use the LP8863EVM.
Default resistor values and jumper positions are set to:
•
Boost SW frequency – 300 kHz (set by external resistor R59)
•
Maximum LED current per string – 120 mA (set by external resistor R57)
•
PWM input to control brightness (register control)
•
PWM output frequency – 9.8 kHz (set by external resistor R58)
•
I
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C interface to communicate with LP8863-Q1 – base address 0x2C
•
Charge pump for SW gate drive enabled
•
J14 : Open to disconnect VDDIO input from V
LDO
out
•
J17 : Open to use internal charge pump
•
J19 : Close to connect onboard LDO outputs (1.8 V from Tiva controller circuit) to VDDIO
•
J31 : Close to connect onboard LDO output (5 V) to VDD input to LP8863-Q1 measurement
•
J12 : Open – probing point of boost output
•
J16 : Open – a probing/noise injecting point for stability measurement