It is mentioned in the datasheet, 3 to 5.25V can be used for LED_DRV_SUP and TX_CTRL_SUP.
Earlier design, we used 5V for these rails and it was proven and worked well.
Now we would like to operate these rails in 3.3V voltage level.
Is it fine to use that, do i need to take care of any other things if i use this voltage level?
Kindly support me for this.
Hi,
Whether to use 3.3V or 5V are mostly depended on the LEDs, connection topology of LEDs, components in series with the LEDs, and what current and/or current range the design may want to drive -
.
So, customers may want to do some tests and V&V before the final decisions.
In addition, please also consider -
"VHR refers to the required voltage headroom necessary to drive the LEDs. See Table 6 for the appropriate VHR value."
"The current source and switches inside the AFE require voltage headroom that mandates the transmitter supply to be a few hundred millivolts higher than the LED forward voltage"
"(1) For a 3-V to 3.6-V supply, use TX_REF = 0.5 V. For a 4.75-V to 5.25-V supply, use TX_REF = 0.75 V or 1.0 V."
More info is available in the 10 Power-Supply Recommendations.
In addition, you may also take a look of these threads -
Thanks
Thanks
