Texas Instruments LDC3114 Manual

LDC3114 4-Channel Hybrid Inductive Touch and Inductance to Digital Converter

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
• 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
– 1.8-V logic output per channel for buttons
2 Applications
• Consumer Electronics:
– Wearables
– Smart Speakers
– Sound Bars
• Industrial Applications:
– HMI Panels and Keypads
– Home Appliances
An IMPORTANT NOTICE at the end of this data sheet addresses availability, warranty, changes, use in safety-critical applications,
intellectual property matters and other important disclaimers. PRODUCTION DATA.
3 Description
The LDC3114 is an inductive sensing device that
enables touch button design for human machine
interface (HMI) on a wide variety of materials by
measuring small deflections of conductive targets
using a coil that can be implemented on a small
printed circuit board (PCB) located behind the panel.
This technology can be used for precise linear
position sensing of metal targets for automotive,
consumer and industrial applications by allowing
LDC2114
access to the raw data representing the inductance
value. Inductive sensing solution is insensitive to
humidity or non-conductive contaminants such as oil
and dirt.
The button mode of LDC3114 is able to automatically
correct for any deformation in the conductive targets.
The LDC3114 offers well-matched channels, which
allow for differential and ratiometric measurements
which enable compensation of environmental and
aging conditions such as temperature and mechanical
drift. The LDC3114 includes an ultra-low power mode
intended for power on/off buttons or position sensors
in battery powered applications.
The LDC3114 is easily configured through an I
interface. The LDC3114 is available in a 16-pin
TSSOP package.
2
C and INTB
LDC3114
(1)
Device Information
PART NUMBER PACKAGE
TSSOP (16)
For all available packages, see the orderable addendum at
the end of the data sheet.
IN0
IN1
Inductive
Resonant
Sensing Core
Circuit
IN2
Driver
IN3
COM
Raw Data
& Config
LDC3114 Simplified Schematic
LDC3114
SNOSDD0 – DECEMBER 2021
2
C
(1)
BODY SIZE (NOM)
5.00 mm × 4.40 mm
VDD
OUT0
Digital OUT1
Button Press 3.3 V
OUT2
Algorithm
OUT3
INTB
LP Mode &
Data
Processing
LPWRB
SCL
2
I C
SDA
GND