The LDC1312/LDC1314 is an inductance-to-digital converter (LDC) that measures the oscillation frequency of multiple LC resonators. The device outputs a digital value that is proportional to frequency, with 12 bits of measurement resolution. This frequency measurement can be converted to an equivalent inductance, or mapped to the movement of an conductive object. The LDC1312/LDC1314 supports a wide range of inductance and capacitor combinations with oscillation frequencies varying from 1 kHz to 10 MHz with equivalent parallel resistances as low as 1.0 kΩ. The device includes a stable internal reference to reduce overall system cost, while also providing the option to drive a clean external oscillator for improved measurement noise. The conversion time of the LDC1312/LDC1314 is configurable per channel, where longer conversion times provide higher effective resolution.
The LDC1312/LDC1314 is configured through a 400-kbit/s I2C bus and includes the ADDR input pin to select an address. The power supply of the device ranges from 2.7 V to 3.6 V. The only external components necessary for operation are the supply bypassing capacitors and I2C pull-ups.