Analog Evaluation
14
SLVUBT6A – October 2019 – Revised May 2020
Copyright © 2019–2020, Texas Instruments Incorporated
Using the TPS8804EVM
Figure 13. LED Driver Settings
Select the LED to be tested. Enable the LED PWM to send the PWM signal to the LEDEN pin. Enable
LEDPIN_EN to control the LED driver using the LEDEN pin. Place a box over the EVM if the EVM LEDs
and photodiode are used to block ambient light and reflect the LED light into the photodiode.
Use an oscilloscope to measure the LED current, photo input amplifier, and photo gain amplifier signals.
Probe LEDEN to measure the LED control signal. Probe CSA or CSB to measure the LED driver current.
Probe PDO to measure the photo input stage amplifier. Probe AMUX_BUF to measure the photo gain
stage amplifier.
