TS-TPC-7990 Power Consumption
The power consumption of the platform can vary depending on the build configuration and run time application/peripheral use. The majority of power savings occur when the CPU and GPU are idle. It is also possible to disable the Ethernet PHY for additional savings. The backlight intensity can be reduced for significant power savings as well.
# Put ETH PHY in reset
echo 116 > /sys/class/gpio/export
echo high > /sys/class/gpio/gpio116/direction
# Put USB hub in reset
echo 43 > /sys/class/gpio/export
echo low > /sys/class/gpio/gpio43/direction
# Lower backlight to 50%
echo 4 > /sys/class/backlight/backlight_local_lcd/brightness
# Disable backlight
echo 0 > /sys/class/backlight/backlight_local_lcd/brightness
In the measurements below, Ethernet is not connected unless otherwise specified and USB serial is disconnected during the measurement. The CPU test is 5x parallel processes of "openssl speed", and the GPU test is Qt5CinematicExperience in the Yocto image.
These tests are performed powering the unit through 5 VDC.
| Test | Max Watts | Average Watts |
|---|---|---|
| CPU 100% + GPU loaded (LCD 100%) + IO + Ethernet | 12.00 (2.40 A) | 8.95 (1.79 A) |
| CPU 100% (LCD 100%) | 8.90 (1.78 A) | 7.80 (1.56 A) |
| CPU Idle (LCD 100%) | 8.35 (1.67 A) | 7.20 (1.44 A) |
| CPU Idle (LCD 50%) | 8.60 (1.72 A) | 6.10 (1.22 A) |
| CPU Idle (LCD 0%) | 4.75 (0.95 A) | 3.90 (0.78 A) |
| CPU Idle (LCD 0%), USB HUB off | 4.10 (0.82 A) | 3.35 (0.67 A) |
| CPU Idle (LCD 0%), USB HUB off, Ethernet PHY in reset | 4.05 (0.81 A) | 2.95 (0.59 A) |
| CPU Idle (LCD 100%) + CPU Ethernet | 9.20 (1.84 A) | 5.70 (1.14 A) |
| CPU Idle (LCD 100%) + USB Ethernet | 5.85 (1.70 A) | 5.70 (1.14 A) |
| Test | Max Watts | Average Watts |
|---|---|---|
| CPU 100% + GPU loaded (LCD 100%) + IO + Ethernet | 18.85 (3.77 A) | 11.25 (2.25 A) |
| CPU 100% (LCD 100%) | 12.20 (2.44 A) | 8.65 (1.73 A) |
| CPU Idle (LCD 100%) | 11.50 (2.30 A) | 9.70 (1.94 A) |
| CPU Idle (LCD 50%) | 11.40 (2.28 A) | 7.90 (1.58 A) |
| CPU Idle (LCD 0%) | 4.65 (0.93 A) | 3.90 (0.78 A) |
| CPU Idle (LCD 0%), USB HUB off | 5.55 (1.11 A) | 3.50 (0.70 A) |
| CPU Idle (LCD 0%), USB HUB off, Ethernet PHY in reset | 4.90 (0.98 A) | 3.05 (0.61 A) |
| CPU Idle (LCD 100%) + CPU Ethernet | 11.20 (2.24 A) | 6.60 (1.32 A) |
| CPU Idle (LCD 100%) + USB Ethernet | 11.60 (2.32 A) | 6.70 (1.34 A) |
The on-board microcontroller is able to disable power to the rest of the platform and restore power after a specified number of seconds or if the touchscreen receives a touch event. The CPU variants will all draw the same amount of power while in sleep mode, however the touchscreen used will impact overall power draw during sleep. These tests are both at 5 VDC.
| Test | Max | Average |
|---|---|---|
| Resistive touch (Okaya or microtips) | 90mW | 20mW |
| Capacitive touch (LXD) | 125mW | 26mW |