UM0452 Datasheet, PDF (7/30 Pages) STMicroelectronics – Temperature sensor evaluation board

UM0452
Getting started
2.2.2
Power supply selection
The board can work in two different power supply modes.
1. External power mode
2. USB powered mode
Selection of required power mode is done by the S1 switch.
1. External power mode selection:
To select for external supply mode place the switch as shown in Figure 3. Then plug in the
12 V adapter with a female connector to the power jacket (J1) and the green LED (EXT)
lights up.
Figure 3. Power selection switch to select external power
2. USB powered mode selection:
To select for USB powered mode plug out the external power supply and then turn the
power switch as shown in Figure 4. Then plug in the USB cable in the USB socket (J2) on
the board. The red LED (USB) lights and board will be powered up with USB power.
Figure 4. Power selection switch to select for USB power
Note:
Only one power supply should be plugged in at once. The power LED ( green for external
supply and red for USB supply) lights up as soon as the power is plugged in, but power is
connected to the board only by the appropriate switch settings as shown in Figure 3 and
Figure 4.
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