SNOA954D November   2019  – June 2021 LDC0851 , LDC1001 , LDC1001-Q1 , LDC1041 , LDC1051 , LDC1101 , LDC1312 , LDC1312-Q1 , LDC1314 , LDC1314-Q1 , LDC1612 , LDC1612-Q1 , LDC1614 , LDC1614-Q1 , LDC2112 , LDC2114 , LDC3114 , LDC3114-Q1

 

  1.   Trademarks
  2. 1LDC Applications
    1. 1.1 Axial Sensing
      1. 1.1.1 Buttons and Keypads
    2. 1.2 Event Counting
    3. 1.3 Other Types of Sensing
  3. 2Inductive Sensing Theory of Operation
  4. 3LDC Device Feature Overview
    1. 3.1 Sample Rate
    2. 3.2 Sensor L Measurement and Reference Frequency
    3. 3.3 Sensor RP Measurement
    4. 3.4 Sensor RP (Current) Drive Capability
    5. 3.5 Switch Output Functionality
    6. 3.6 Sensor Frequency Range
    7. 3.7 Multi-Channel Sensing
    8. 3.8 Power Management
    9. 3.9 Internal Algorithms
  5. 4Device Families
    1. 4.1 Inductive Touch Devices
      1. 4.1.1 Inductive Touch LDC Recommended Applications
    2. 4.2 Multichannel LDC Devices
      1. 4.2.1 Multi-Channel LDC Recommended Applications
      2. 4.2.2 LDC1101
        1. 4.2.2.1 LDC1101 Recommended Applications
      3. 4.2.3 LDC0851
        1. 4.2.3.1 Recommended Applications
  6. 5Summary
  7. 6Revision History

3.4 Sensor RP (Current) Drive Capability

As the target gets closer to the sensor, more energy is dissipated in the target eddy currents. This energy loss needs to be replaced by the LDC device in order to maintain the sensor oscillation. Each LDC has a minimum sensor RP which it can drive; where a lower RP is a sensor with more loss. Being able to drive a higher loss sensor is desirable and provides more system design flexibility. The RP drive is a consideration even for L measurement applications.

Terminology for the sensor drive varies with device – on the LDC1101, the RPMIN setting is used for to control the sensor drive. With the LDC1312, LDC1314, LDC1612, and LDC1614 devices, the sensor drive is configured by the IDRIVE setting.

An application using the LDC0851, as long as the sensor inductance and capacitance are within the operating range specified in the data sheet, does not need to consider the sensor RP due to the sensor driver circuit design.