User manual

...the world's most energy friendly microcontrollers
2013-10-10 - t0014_0.21 9
www.silabs.com
5.5 LC Sensor
In the bottom right corner there is an inductive-capacitive sensor for demonstrating the low energy sensor
interface. By setting up oscillating currents in the inductor, metal nearby the inductor can be sensed by
measuring the oscillation decay time. The effective range is a few millimeters.
Figure 5.5. LC Metal Sensor
PB12 (DAC0_OUT1)
PC7 (ACMP0_CH7)
EFM32 MCU
100 nF
330 pF
390 uH
1.5K
DAC_LC_EXCITE
LES_LC_SENSE
Metal Object