Differential inductive switch for MCU-less applications


Product details


Applications Metal proximity detection, Encoders/event counters Number of input channels 1 Vs (Max) (V) 3.46 Vs (Min) (V) 1.71 Operating temperature range (C) -40 to 125 open-in-new Find other Inductive sensor AFEs

Package | Pins | Size

WSON (DSG) 8 4 mm² 2 x 2 open-in-new Find other Inductive sensor AFEs


  • Threshold tolerance: <1 % of coil diameter
  • Temperature stable switching operation
  • Average Supply Current: < 20 µA @ 10 sps
  • Shutdown Supply Current: 140 nA
  • Push-pull output
  • Resistor Programmable Threshold
  • Insensitive to DC Magnetic Fields
  • Contactless Switching Operation
  • Sample Rate up to 4 ksps
  • Supply Voltage: 1.8 V – 3.3 V
  • Operating Temperature Range: –40 to 125 °C
open-in-new Find other Inductive sensor AFEs


The LDC0851 is a close range inductive switch ideal for contactless and robust applications such as presence detection, event counting, and simple buttons.

The switch is triggered when a conductive object comes within close proximity of the sensing coil. Hysteresis is included to ensure a reliable switching threshold immune to mechanical vibration. The differential implementation prevents false triggering over environmental factors such as temperature variation or humidity effects.

Inductive sensing technology provides reliable and accurate sensing even in the presence of dirt, oil, or moisture making it ideal for use in harsh or dirty environments. The solid state switching eliminates the failures due to reed, mechanical, or contact switching. Unlike competitive products, the LDC0851 does not require magnets, nor is it affected by DC magnetic fields.

open-in-new Find other Inductive sensor AFEs

Technical documentation

star = Top documentation for this product selected by TI
No results found. Please clear your search and try again.
View all 15
Type Title Date
* Data sheet LDC0851 Differential Inductive Switch datasheet (Rev. A) Jan. 16, 2016
Application note Common Inductive and Capacitive Sensing Applications (Rev. B) Jun. 22, 2021
Application note Simulate Inductive Sensors Using FEMM (Finite Element Method Magnetics) (Rev. A) Jun. 16, 2021
Application note LDC Device Selection Guide (Rev. D) Jun. 15, 2021
Application note Sensor Design for Inductive Sensing Applications Using LDC (Rev. C) May 21, 2021
Application note LDC Target Design (Rev. B) May 13, 2021
Application note LDC0851 Quick-Start Guide (Rev. A) Feb. 07, 2020
Technical article Understanding tamper detection sensors Nov. 18, 2019
Technical article An open-and-shut case, part 2: advantages of inductive-based case tamper detection in smart meters Nov. 29, 2018
Technical article An open-and-shut case, part 1: limitations of mechanical case tamper detection in smart meters Nov. 15, 2018
Application note LDC0851 Stacked Coil Design Considerations Feb. 12, 2018
User guide LDC0851EVM User's Guide (Rev. A) Jul. 30, 2017
Application note EMI Considerations for Inductive Sensing Feb. 22, 2017
Technical article Inductive sensing: reliably detect faults in circuit breakers using contactless inductive switches Jan. 17, 2017
Application note LDC0851 - Troubleshooting Jan. 03, 2017

Design & development

For additional terms or required resources, click any title below to view the detail page where available.

Hardware development

document-generic User guide

The LDC0851 evaluation module demonstrates inductive sensing technology to accurately detect the presence of a conductive target passing a fixed threshold. The evaluation module includes a perforated and interchangeable 4-layer PCB where both the sensing coil and reference coil are stacted for (...)

  • 1.8V - 3.3 V operating voltage
  • Includes a stacked coil for rapid prototyping
  • Push/Pull output
  • Adjustable switching distance threshold for evaluating a wide variety of use cases
  • No GUI or MCU required
  • Temperature and other environmental variation compensated by matching sense and reference coils

Design tools & simulation

SLYM096.ZIP (29 KB) - IBIS Model
SLYC137F.ZIP (984 KB)

Reference designs

Inductive Sensing 32-Position Encoder Knob Reference Design using the LDC0851
TIDA-00828 — An inductive sensing based incremental encoder knob design can provide a robust and low-cost interface for control inputs.  It can reliably operate in environments which have dirt, moisture, or oil which would pose issues for alternate sensing technologies. This solution requires no magnets.
document-generic Schematic document-generic User guide
Case Tamper Detection Reference Design Using Inductive Sensing
TIDA-01377 — The physical case surrounding a smart meter is the first line of defense against tampering. Smart meter designs must incorporate some way to detect when the meter case is opened in order to alert service providers to a possible tamper attack.  This reference design implements a new method for (...)
document-generic Schematic document-generic User guide
LDC0851 Event Counting Reference Design
TIDA-00851-LDC0851 — An inductive sensing (LDC)-based event counting design providing a robust and low-cost interface for speed measurement and event counting applications.  The solution doesn't require magnets and reliably operates in environments with dirt, moisture or oil that usually pose challenges for (...)
document-generic Schematic document-generic User guide

CAD/CAE symbols

Package Pins Download
WSON (DSG) 8 View options

Ordering & quality

Information included:
  • RoHS
  • Device marking
  • Lead finish/Ball material
  • MSL rating/Peak reflow
  • MTBF/FIT estimates
  • Material content
  • Qualification summary
  • Ongoing reliability monitoring

Recommended products may have parameters, evaluation modules or reference designs related to this TI product.

Support & training

TI E2E™ forums with technical support from TI engineers

Content is provided "as is" by TI and community contributors and does not constitute TI specifications. See terms of use.

If you have questions about quality, packaging or ordering TI products, see TI support. ​​​​​​​​​​​​​​