I ordered a
DISPLAY_ILI9341_TOUCH and I want to power it from 5V. I am designing a power circuit and wanted to know, what is the power consumption for this device?
Funny you should ask! A few days ago, I had a setup to measure power consumption of the T4.1 while writing to the SD Card. The setup uses a high-side current sensor on the T4.1 power input and measures the current at 16,000 samples per second. I connected the setup to my T4.1 with the ILI9341 display and recorded the power consumption while reading in a QVGA image from SD, then dissolving in a second image.
The ILI9341 backlight is fed the input 5V through a 100-ohm current limiting resistor. The baseline current of the T4.1 is about 125mA at 600MHz. With the ILI9341 displaying a static image, the current rises to about 165mA. The extra 40mA seems consistent with the resistor value and about a 1V drop across the backlight LED.
Strangely, the overall current drops when the PXP is actively managing a 30-step dissolve into a new slide. There are some expected current spikes to about 230 to 240mA when the new files are being read from the SD card.
Here is a plot of the current data vs time:
A file has already been read and is being displayed at T=0. At about T=17, file 1 is read and displayed. At T=26, a file 2 is read and dissolves in over file 1. The drop in current during the transition is apparent and unexplained.