SNOSDD0
December 2021
LDC3114
PRODUCTION DATA
1
Features
2
Applications
3
Description
4
Revision History
5
Pin Configuration and Functions
6
Specifications
6.1
Absolute Maximum Ratings
6.2
ESD Ratings
6.3
Recommended Operating Conditions
6.4
Thermal Information
6.5
Electrical Characteristics
6.6
Digital Interface
6.7
I2C Interface
6.8
Timing Diagram
6.9
Typical Characteristics
7
Detailed Description
7.1
Overview
7.2
Functional Block Diagram
7.3
Feature Description
7.3.1
Multimode Operation
7.3.2
Multichannel and Single-Channel Operation
7.3.3
Raw Data Output
7.3.4
Button Output Interfaces
7.3.5
Programmable Button Sensitivity
7.3.6
Baseline Tracking
7.3.7
Integrated Button Algorithms
7.3.8
I2C Interface
7.3.8.1
I2C Interface Specifications
7.3.8.2
I2C Bus Control
7.4
Device Functional Modes
7.4.1
Normal Power Mode
7.4.2
Low Power Mode
7.4.3
Configuration Mode
7.5
Register Maps
7.5.1
LDC3114 Registers
7.5.2
Gain Table for Registers GAIN0, GAIN1, GAIN2, and GAIN3
8
Application and Implementation
8.1
Application Information
8.1.1
Theory of Operation
8.1.2
Designing Sensor Parameters
8.1.3
Setting COM Pin Capacitor
8.1.4
Defining Power-On Timing
8.1.5
Configuring Button or Raw Data Scan Rate
8.1.6
Programming Button or Raw Data Sampling Window
8.1.7
Scaling Frequency Counter Output
8.1.8
Setting Button Triggering Threshold
8.1.9
Tracking Baseline
8.1.10
Mitigating False Button Detections
8.1.10.1
Eliminating Common-Mode Change (Anti-Common)
8.1.10.2
Resolving Simultaneous Button Presses (Max-Win)
8.1.10.3
Overcoming Case Twisting (Anti-Twist)
8.1.10.4
Mitigating Metal Deformation (Anti-Deform)
8.1.11
Reporting Interrupts for Button Presses, Raw Data Ready and Error Conditions
8.1.12
Estimating Supply Current
8.2
Typical Application
8.2.1
Touch Button Design
8.2.1.1
Design Requirements
8.2.1.2
Detailed Design Procedure
8.2.1.3
Application Curves
9
Power Supply Recommendations
10
Layout
10.1
Layout Guidelines
10.2
Layout Example
11
Device and Documentation Support
11.1
Documentation Support
11.1.1
Related Documentation
11.2
Receiving Notification of Documentation Updates
11.3
Support Resources
11.4
Trademarks
11.5
Electrostatic Discharge Caution
11.6
Glossary
12
Mechanical, Packaging, and Orderable Information
Package Options
Mechanical Data (Package|Pins)
PW|16
MPDS361A
Thermal pad, mechanical data (Package|Pins)
Orderable Information
snosdd0_oa
snosdd0_pm
1
Features
Multiple modes of operation:
Raw data mode: access pre-processed inductance measurement data to enable advanced algorithms on MCU for linear sensing
Button mode: button press detection with baseline tracking and advanced on-chip post processing
Force level measurement of touch buttons
Pin and register compatible to
LDC2114
Robust EMI performance allows for CISPR 22 and CISPR 24 compliance
Four independent channel operation
Configurable scan rates:
0.625 SPS to 160 SPS
Continuous scanning option
Advanced button press detection algorithms:
Adjustable force threshold per button
Environmental shift compensation
Simultaneous button press detection
Low current consumption:
One button: 6 µA at 0.625 SPS
Two buttons: 72 µA at 20 SPS
Temperature range
TSSOP (16) : –40°C to +125°C
Interface:
1.8-V and 3.3-V compliant I
2
C and INTB
1.8-V logic output per channel for buttons