Datasheet

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IN0A

IN0B

IN1A

IN1B

LDC1612

VDD

Core

GND

SCL

SDA

CLKIN

ADDR

INTB

Sensor 0

GND

MCU

VDD

Peripheral

3.3 V

GPIO

3.3 V

40 MHz

Target

Sensor 1

Target

Sensing Range (Target Distance / ‡

SENSOR

)

Measurement Precision (µm)

0 20% 40% 60% 80% 100%

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

D002

Product

Folder

Order

Now

Technical

Documents

Tools &

Software

Support &

Community

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.

LDC1612

LDC1614

SNOSCY9A –DECEMBER 2014–REVISED MARCH 2018

LDC1612, LDC1614 Multi-Channel 28-Bit Inductance to Digital Converter (LDC) for

Inductive Sensing

1 Features

• Easy-to-Use – Minimal Configuration Required

• Up to 4 Channels With Matched Sensor Drive

• Multiple Channels Support Environmental and

Aging Compensation

• Remote Sensor Position of >20 cm Supports

Operation In Harsh Environments

• Pin-Compatible Medium and High-Resolution

Options:

– LDC1312/4: 2/4-ch 12-Bit LDC

– LDC1612/4: 2/4-ch 28-Bit LDC

• Sensing Range Beyond Two Coil Diameters

• Supports Wide Sensor Frequency Range of 1 kHz

to 10 MHz

• Power Consumption:

– 35 µA Low Power Sleep Mode

– 200 nA Shutdown Mode

• 2.7 V to 3.6 V Operation

• Multiple Reference Clocking Options:

– Included Internal Clock For Lower System

Cost

– Support for 40 MHz External Clock For Higher

System performance

• Immunity to DC Magnetic Fields and Magnets

2 Applications

• Knobs in Consumer, Appliances, and Automotive

• Buttons in Home Electronics, Wearables,

Manufacturing, and Automotive

• Keypads in Manufacturing and Appliances

• Slider Buttons in Consumer Products

• Metal Detection in Industrial and Automotive

• POS and EPOS

3 Description

The LDC1612 and LDC1614 are 2- and 4-channel,

28-bit inductance to digital converters (LDCs) for

inductive sensing solutions. With multiple channels

and support for remote sensing, the LDC1612 and

LDC1614 enable the performance and reliability

benefits of inductive sensing to be realized at minimal

cost and power. The products are easy to use, only

requiring that the sensor frequency be within 1 kHz

and 10 MHz to begin sensing. The wide 1 kHz to 10

MHz sensor frequency range also enables use of

very small PCB coils, further reducing sensing

solution cost and size.

The high resolution channels allow for a much larger

sensing range, maintaining good performance

beyond two coil diameters. Well-matched channels

allow for differential and ratiometric measurements,

which enable designers to use one channel to

compensate their sensing for environmental and

aging conditions such as temperature, humidity, and

mechanical drift.

Given their ease of use, low power, and low system

cost these products enable designers to greatly

improve performance, reliability, and flexibility over

existing sensing solutions and to introduce brand new

sensing capabilities to products in all markets,

especially consumer and industrial applications.

These devices are easily configured via an I2C

interface. The two-channel LDC1612 is available in a

WSON-12 package and the four-channel LDC1614 is

available in a WQFN-16 package.

Device Information

(1)

PART NUMBER PACKAGE BODY SIZE (NOM)

LDC1612 WSON-12 4 mm × 4 mm

LDC1614 WQFN-16 4 mm × 4 mm

(1) For all available packages, see the orderable addendum at

the end of the datasheet.

Simplified Schematic

Measurement Precision vs. Target Distance

Summary of content (65 pages)

PAGE 1
Product Folder Order Now Support & Community Tools & Software Technical Documents LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 LDC1612, LDC1614 Multi-Channel 28-Bit Inductance to Digital Converter (LDC) for Inductive Sensing 1 Features 3 Description • • • The LDC1612 and LDC1614 are 2- and 4-channel, 28-bit inductance to digital converters (LDCs) for inductive sensing solutions.
PAGE 2
LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Table of Contents 1 2 3 4 5 6 7 Features .................................................................. Applications ........................................................... Description ............................................................. Revision History..................................................... Pin Configuration and Functions ......................... Specifications.....................................
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Revision History (continued) • Changed description of clocking architecture for improved clarity. ..................................................................................... 45 • Changed description of clocking usage for clarity. .............................................................................................................. 45 • Changed reference frequency limits from < to ≤ ............................
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 5 Pin Configuration and Functions CLKIN 3 10 ADDR 4 INTB SD IN3A IN2B IN2A 15 14 13 IN1B 11 IN1A 3 10 IN0B 4 9 IN0A 1 IN0B SDA 2 9 IN0A CLKIN 5 8 GND ADDR 6 7 VDD DAP IN3B 12 SCL DAP 8 IN1A GND 11 7 2 VDD SDA 6 IN1B SD 12 5 1 INTB SCL 16 DNT and RGH Packages Top View LDC1614 WQFN-16 LDC1612 WSON-12 Pin Functions PIN NAME NO.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 6 Specifications 6.1 Absolute Maximum Ratings MIN MAX UNIT 5 V VDD Supply Voltage Range Vi Voltage on any pin -0.3 VDD+0.3 V IA Input current on any INx pin -8 8 mA ID Input current on any Digital pin -5 5 mA Tj Junction Temperature -55 150 °C Tstg Storage temperature range -65 150 °C (1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 6.5 Electrical Characteristics Unless otherwise specified, all limits ensured for TA = 25°C, VDD = 3.3 V. See (1) (2) MIN (3) TYP (4) MAX (3) PARAMETER TEST CONDITIONS UNIT VDD Supply Voltage TA = -40°C to +125°C IDD Supply Current (not including sensor current) (5) ƒCLKIN = 10 MHz IDDSL Sleep Mode Supply Current (5) SLEEP_MODE_EN = b1 35 60 µA ISD Shutdown Mode Supply Current (5) SD = VDD 0.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Electrical Characteristics (continued) Unless otherwise specified, all limits ensured for TA = 25°C, VDD = 3.3 V. See (1) TEST CONDITIONS (2) PARAMETER ƒINTCLK Internal Reference Clock Frequency range TCf_int_μ Internal Reference Clock Temperature Coefficient mean MIN (3) TYP (4) MAX (3) UNIT 35 43.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 6.7 Typical Characteristics Common test conditions (unless specified otherwise): Sensor inductor: 2 layer, 32 turns/layer, 14 mm diameter, PCB inductor with L=19.4 µH, RP=5.7 kΩ at 2 MHz; Sensor capacitor: 330 pF 1% COG/NP0; Target: Aluminum, 1.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Typical Characteristics (continued) Common test conditions (unless specified otherwise): Sensor inductor: 2 layer, 32 turns/layer, 14 mm diameter, PCB inductor with L=19.4 µH, RP=5.7 kΩ at 2 MHz; Sensor capacitor: 330 pF 1% COG/NP0; Target: Aluminum, 1.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7 Detailed Description 7.1 Overview The LDC1612/LDC1614 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 28 bits of measurement resolution. This frequency measurement can be converted to an equivalent inductance, or mapped to the movement of an conductive object.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Feature Description (continued) At the end of each conversion in single channel mode, or after converting all selected channels when in multichannel mode, the LDC1612/LDC1614 can be configured to assert the INTB pin to indicate completion of the conversion. Refer to Multi-Channel and Single Channel Operation for details on the LDC1612/LDC1614 channel functionality and configuration. 7.3.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Feature Description (continued) 7.3.6 Device Status Monitoring The LDC1612/LDC1614 can monitor attached sensors and can report on device status and sensor status via the I2C interface.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.5 Programming The LDC1612/4 device uses an I2C interface to access control and data registers. The recommended configuration procedure is to put the device into Sleep Mode, set the appropriate registers, and then enter Normal Mode. Conversion results must be read while the device is in Normal Mode. Setting the device into Shutdown mode will reset the device configuration. 7.5.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Programming (continued) 7.5.2 Pulses on I2C The I2C interface of the LDC is designed to operate with the standard I2C transactions detailed in the I2C specification; however it is not suitable for use in an I2C system which supports early termination of transactions.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6 Register Maps 7.6.1 Register List Fields indicated with Reserved must be written only with indicated value, otherwise improper device operation may occur. The R/W column indicates the Read-Write status of the corresponding field. A ‘R/W’ entry indicates read and write capability, a ‘R’ indicates read-only, and a ‘W’ indicates write-only.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.2 Address 0x00, DATA0_MSB Figure 15. Address 0x00, DATA0_MSB 15 ERR_UR0 14 ERR_OR0 13 ERR_WD0 12 ERR_AE0 11 7 6 5 4 3 10 9 8 1 0 DATA0 [27:16] 2 DATA [27:16] LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 1.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.4 Address 0x02, DATA1_MSB Figure 17. Address 0x02, DATA1_MSB 15 ERR_UR1 14 ERR_OR1 13 ERR_WD1 12 ERR_AE1 11 7 6 5 4 3 10 9 8 1 0 DATA1[27:16] 2 DATA1[27:16] LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 3. Address 0x02, DATA1_MSB Field Descriptions Bit Field Type Reset Description 15 ERR_UR1 R 0 Channel 1 Conversion Under-range Error Flag Cleared by reading the bit.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.6 Address 0x04, DATA2_MSB (LDC1614 only) Figure 19. Address 0x04, DATA2_MSB 15 ERR_UR2 14 ERR_OR2 13 ERR_WD2 12 ERR_AE2 11 7 6 5 4 3 10 9 8 1 0 DATA2 [27:16] 2 DATA2 [27:16] LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 5.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.8 Address 0x06, DATA3_MSB (LDC1614 only) Figure 21. Address 0x06, DATA3_MSB 15 ERR_UR3 14 ERR_OR3 13 ERR_WD3 12 ERR_AE3 11 7 6 5 4 3 10 9 8 1 0 DATA3 [27:16] 2 DATA3 [27:16] LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 7.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.10 Address 0x08, RCOUNT0 Figure 23. Address 0x08, RCOUNT0 15 14 13 12 11 10 9 8 3 2 1 0 RCOUNT0 7 6 5 4 RCOUNT0 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 9.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.13 Address 0x0B, RCOUNT3 (LDC1614 only) Figure 26. Address 0x0B, RCOUNT3 15 14 13 12 11 10 9 8 3 2 1 0 RCOUNT3 7 6 5 4 RCOUNT3 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 12.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.16 Address 0x0E, OFFSET2 (LDC1614 only) Figure 29. Address 0x0E, OFFSET2 15 14 13 12 11 10 9 8 3 2 1 0 OFFSET2 7 6 5 4 OFFSET2 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 15. Address 0x0E, OFFSET2 Field Descriptions Bit 15:0 Field Type Reset Description OFFSET2 R/W 0x0000 Channel 2 Conversion Offset ƒOFFSET_2 = (OFFSET2÷216)×ƒREF2 7.6.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.19 Address 0x11, SETTLECOUNT1 Figure 32. Address 0x11, SETTLECOUNT1 15 14 13 12 11 SETTLECOUNT1 10 9 8 7 6 5 4 3 SETTLECOUNT1 2 1 0 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 18.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.21 Address 0x13, SETTLECOUNT3 (LDC1614 only) Figure 34. Address 0x13, SETTLECOUNT3 15 14 13 12 11 SETTLECOUNT3 10 9 8 7 6 5 4 3 SETTLECOUNT3 2 1 0 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 20.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.23 Address 0x15, CLOCK_DIVIDERS1 Figure 36. Address 0x15, CLOCK_DIVIDERS1 15 7 14 13 FIN_DIVIDER1 12 11 6 4 3 FREF_DIVIDER1 10 9 8 FREF_DIVIDER1 2 1 RESERVED 5 0 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 22.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.25 Address 0x17, CLOCK_DIVIDERS3 (LDC1614 only) Figure 38. Address 0x17, CLOCK_DIVIDERS3 15 7 14 13 FIN_DIVIDER3 12 11 6 4 3 FREF_DIVIDER3 10 9 8 FREF_DIVIDER3 2 1 RESERVED 5 0 LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 24. Address 0x17, CLOCK_DIVIDERS3 Bit Field Type Reset Description 15:12 FIN_DIVIDER3 R/W 0000 Channel 3 Input Divider Sets the divider for Channel 3 input.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Table 25. Address 0x18, STATUS Field Descriptions (continued) Bit Field Type Reset Description 11 ERR_WD R 0 Watchdog Timeout Error b0: No Watchdog Timeout error was recorded since the last read of the STATUS register. b1: An active channel has generated a Watchdog Timeout error. Refer to STATUS.ERR_CHAN field to determine which channel is the source of this error.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.27 Address 0x19, ERROR_CONFIG Figure 40. Address 0x19, ERROR_CONFIG 15 UR_ERR2OUT 14 OR_ERR2OUT 13 WD_ ERR2OUT 12 AH_ERR2OUT 11 AL_ERR2OUT 10 9 RESERVED 8 7 UR_ERR2INT 6 OR_ERR2INT 5 WD_ERR2INT 4 AH_ERR2INT 3 AL_ERR2INT 2 ZC_ERR2INT 1 Reserved 0 DRDY_2INT LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 26.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Table 26. Address 0x19, ERROR_CONFIG (continued) Bit Field Type Reset Description 3 AL_ERR2INT R/W 0 Amplitude Low Error to INTB b0: Do not report Amplitude Low errors by asserting INTB pin and STATUS register. b1: Report Amplitude Low errors by asserting INTB pin and updating STATUS.ERR_ALE register field.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Table 27. Address 0x1A, CONFIG Field Descriptions (continued) Bit Field Type Reset Description 10 AUTO_AMP_DIS R/W 0 Automatic Sensor Amplitude Correction Disable Setting this bit will disable the automatic Amplitude correction algorithm and stop the updating of the INIT_IDRIVEx field. b0: Automatic Amplitude correction enabled. b1: Automatic Amplitude correction is disabled. Recommended for precision applications.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.30 Address 0x1C, RESET_DEV Figure 43. Address 0x1C, RESET_DEV 15 RESET_DEV 14 13 12 7 6 5 4 11 RESERVED 10 9 8 3 2 1 0 RESERVED LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 29. Address 0x1C, RESET_DEV Field Descriptions Bit Field Type Reset Description 15 RESET_DEV R/W 0 Device Reset Write b1 to reset the device. Will always readback 0. 14:0 RESERVED R/W 0x0000 Reserved.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 7.6.32 Address 0x1F, DRIVE_CURRENT1 Figure 45. Address 0x1F, DRIVE_CURRENT1 15 7 14 13 IDRIVE1 12 11 6 5 4 3 INIT_IDRIVE1 10 9 INIT_IDRIVE1 8 2 1 0 RESERVED LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 31.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 7.6.34 Address 0x21, DRIVE_CURRENT3 (LDC1614 only) Figure 47. Address 0x21, DRIVE_CURRENT3 15 14 13 IDRIVE3 12 11 6 5 4 3 7 INIT_IDRIVE3 10 9 INIT_IDRIVE3 8 2 1 0 RESERVED LEGEND: R/W = Read/Write; R = Read only; -n = value after reset Table 33.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 8 Application and Implementation NOTE Information in the following applications sections is not part of the TI component specification, and TI does not warrant its accuracy or completeness. TI’s customers are responsible for determining suitability of components for their purposes. Customers should validate and test their design implementation to confirm system functionality. 8.1 Application Information 8.1.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Application Information (continued) Distance-dependent coupling M(d) Eddy Current CPAR Distance (d) Target Resistance Coil Series Resistance (Rs) I RP(d) L(d) CPAR + CTANK Parallel Electrical Model, L-C Tank Copyright © 2016, Texas Instruments Incorporated Figure 50.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Application Information (continued) Texas Instruments' WEBENCH design tool can be used for coil design, in which the parameter values for RP, L and C are calculated. See http://www.ti.com/webench. RP is a function of target distance, target material, and sensor characteristics. Figure 51 shows an example of RP variation based on the distance between the sensor and the target.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Application Information (continued) 4 24 Target D = 1 x coil ‡ 3.5 21 3 18 2.5 15 2 12 1.5 Inductance (µH) Sensor Frequency (MHz) Target D = 0.5 x coil ‡ 9 Sensor Frequency (MHz) Inductance (µH) 1 0 1 2 3 4 6 5 6 7 8 9 10 11 12 13 14 Target Distance D (mm) D011 Figure 52. Example Sensor Frequency, Inductance vs. Target Distance with 14 mm PCB Coil and 1.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Application Information (continued) Active Channel Sensor Signal Sensor Activation Conversion Conversion Amplitude Correction Conversion Amplitude Correction Amplitude Correction Figure 54. Single-Channel Mode Sequencing Table 36.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 8.1.3.1 Data Offset An offset value may be subtracted from each DATA value to compensate for a frequency offset or maximize the dynamic range of the sample data. The offset values should be < ƒSENSORx_MIN / ƒREFx. Otherwise, the offset might be so large that it masks the LSBs which are changing. Table 38.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 8.1.4.1 Settling Time When the LDC sequences through the channels in multi-channel mode, the dwell time interval for each channel is the sum of 3 parts: sensor activation time + conversion time + channel switch delay. The sensor activation time is the amount of settling time required for the sensor oscillation amplitude to stabilize, as shown in Figure 53.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Full Current Activation settle time Low Power Activation settle time Sensor Amplitude Time Figure 55. Sensor Full Current Activation vs. Low Power Activation 8.1.5 Sensor Current Drive Configuration The registers listed in Table 41 are used to control the sensor drive current so that the sensor signal amplitude is within the optimum range of 1.2 VP to 1.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Table 41. Current Drive Control Registers CHANNEL (1) REGISTER FIELD [ BIT(S) ] CONFIG, addr 0x1A VALUE SENSOR_ACTIVATE_SEL [11] Sets current drive for sensor activation. Recommended value is b0 (Full Current mode). RP_OVERRIDE_EN [12] Set to b1 for normal operation (RP Override enabled) AUTO_AMP_DIS [10] Disables Automatic amplitude correction.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Table 42. Optimum Sensor RP Ranges for Sensor IDRIVEx Setting. (continued) IDRIVEx Register Field Value Nominal Sensor Current (µA) Minimum Sensor RP Maximum Sensor RP (kΩ) (kΩ) 9 b01001 59 16.1 23.6 10 b01010 72 13.1 20.4 11 b01011 82 11.5 17.6 12 b01100 95 9.92 15.1 13 b01101 110 8.57 13.0 14 b01110 127 7.42 11.2 15 b01111 146 6.46 9.69 16 b10000 169 5.58 8.35 17 b10001 195 4.83 7.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 8.1.5.2 Automatic IDRIVE Setting with RP_OVERRIDE_EN The LDC1612/LDC1614 can automatically determine the appropriate sensor current drive when entering Active Mode. For the majority of applications, it is recommended to program a fixed current drive for consistent measurement performance. The automatic sensor amplitude setting is useful for initial system prototyping if the sensor amplitude is unknown.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 8.1.5.5 Channel 0 High Current Drive Channel 0 provides a high sensor current drive mode to drive sensor coils with a typical drive current >3.5 mA. This feature can be used to drive sensors with an RP lower than 350 Ω. Set the HIGH_CURRENT_DRV field to b1 to enable this mode. This drive mode is only available on Channel 0, and can only be enabled in single channel mode (AUTOSCAN_EN = 0). 8.1.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Table 43. Clock Frequency Requirements REFERENCE SOURCE MODE (1) Multi-Channel Single-Channel (1) (2) VALID ƒREFx RANGE Internal ƒREFx ≤ 55 MHz External ƒREFx ≤ 40 MHz Either external or internal ƒREFx ≤ 35 MHz VALID ƒINx RANGE SET FIN_DIVIDERx to ≥ b0001 < ƒREFx /4 (2) VALID VALID RCOUNTx SETTLECOUNTx SETTINGS SETTINGS >3 >8 Channels 2 and 3 are only available for LDC1614 If ƒSENSOR ≥ 8.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 8.1.8 Device Status Registers The LDC1612/LDC1614 can monitor and report on conversion results and the status of attached sensors using the registers listed in Table 46. Table 46. Status Registers CHANNEL (1) (1) REGISTER FIELDS [ BIT(S) ] VALUES All STATUS, addr 0x18 Refer to Register Maps section 12 fields are available that for a description of the individual contain various status bits [ 15:0 ] status bits.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 8.2 Typical Application 8.2.1 System Sensing Functionality Inductive sensing provides a wide range of system advantages that no other technology can provide - contactless measurement, resistance to dirt/dust/water, immunity to external magnets, remote sensor positioning, inexpensive and robust sensors, and extremely high resolution measurement of relative movement.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com Typical Application (continued) 8.2.4 Detailed Design Procedure 1. 2. 3. 4. 5. 6. 7. 8. 50 The target distance, resolution and diameter are used as inputs to WEBENCH to design the sensor coil, The resulting coil design is a 2 layer coil, with an area of 2.5 cm2, diameter of 17.7 mm, and 39 turns. The values for RP, L and C are: RP = 6.6 kΩ, L = 43.9 µH, C = 100 pF.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 Typical Application (continued) h. The combined value for the CONFIG register (address 0x1A) is 0x1601. We then read the conversion results for channel 0 and channel 1 every 1.00 ms from register addresses 0x00 to 0x03. 8.2.5 Recommended Initial Register Configuration Values Based on the example configuration in section Detailed Design Procedure, the following register write sequence is recommended: Table 47.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 8.2.6 Application Curves Common Test Conditions (unless specified otherwise): • Sensor inductor: 2 layer, 32 turns/layer, 14mm diameter, PCB inductor with L=19.4 µH, RP=5.7 kΩ at 2 MHz • Sensor capacitor: 330 pF 1% COG/NP0 • Target: Aluminum, 1.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 8.2.7 Inductor Self-Resonant Frequency Every inductor has a distributed parasitic capacitance, which is dependent on construction and geometry. At the Self-Resonant Frequency (SRF), the reactance of the inductor cancels the reactance of the parasitic capacitance. Above the SRF, the inductor will electrically appear to be a capacitor.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 10 Layout 10.1 Layout Guidelines Avoid long traces between the sensor and the LDC - higher frequency sensors may need to be placed closer to the device to minimize noise. The INAx and INBx traces should be routed as differential pairs - run the traces in parallel and close together. Lower trace impedances (even well below 100 Ω) are acceptable, as they reduce any parasitic inductance.
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LDC1612, LDC1614 www.ti.com SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 11 Device and Documentation Support 11.1 Device Support 11.1.1 Development Support For related links, see the following: • Texas Instruments' WEBENCH tool: http://www.ti.com/webench 11.2 Documentation Support 11.2.
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LDC1612, LDC1614 SNOSCY9A – DECEMBER 2014 – REVISED MARCH 2018 www.ti.com 11.6 Trademarks E2E is a trademark of Texas Instruments. WEBENCH is a registered trademark of Texas Instruments. 11.7 Electrostatic Discharge Caution These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates. 11.8 Glossary SLYZ022 — TI Glossary.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 30-Jun-2015 Important Information and Disclaimer:The information provided on this page represents TI's knowledge and belief as of the date that it is provided. TI bases its knowledge and belief on information provided by third parties, and makes no representation or warranty as to the accuracy of such information. Efforts are underway to better integrate information from third parties.
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PACKAGE MATERIALS INFORMATION www.ti.com 30-Jun-2015 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing LDC1612DNTR WSON DNT 12 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 4500 330.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1 LDC1612DNTT WSON DNT 12 250 178.0 12.4 4.3 4.3 1.3 8.0 12.0 Q1 LDC1614RGHR WQFN RGH 16 4500 330.0 12.4 4.3 4.3 1.3 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 30-Jun-2015 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LDC1612DNTR WSON DNT 12 4500 367.0 367.0 35.0 LDC1612DNTT WSON DNT 12 250 210.0 185.0 35.0 LDC1614RGHR WQFN RGH 16 4500 367.0 367.0 35.0 LDC1614RGHT WQFN RGH 16 250 210.0 185.0 35.
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PACKAGE OUTLINE RGH0016A WQFN - 0.8 mm max height SCALE 3.000 PLASTIC QUAD FLATPACK - NO LEAD 4.1 3.9 B A 0.5 0.3 PIN 1 INDEX AREA 0.3 0.2 4.1 3.9 DETAIL OPTIONAL TERMINAL TYPICAL DIM A OPT 1 OPT 1 (0.1) (0.2) C 0.8 MAX SEATING PLANE 0.05 0.00 0.08 2.6 0.1 5 SEE TERMINAL DETAIL (A) TYP 8 EXPOSED THERMAL PAD 12X 0.5 4 9 17 4X 1.5 SYMM 1 12 16X PIN 1 ID (OPTIONAL) 16 SYMM 13 16X 0.3 0.2 0.1 0.05 C A B 0.5 0.3 4214978/B 01/2017 NOTES: 1. All linear dimensions are in millimeters.
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EXAMPLE BOARD LAYOUT RGH0016A WQFN - 0.8 mm max height PLASTIC QUAD FLATPACK - NO LEAD ( 2.6) SYMM 16 13 16X (0.6) (R0.05) TYP 1 12 16X (0.25) SYMM 17 (3.8) (1) 12X (0.5) 9 4 ( 0.2) TYP VIA 8 5 (1) (3.8) LAND PATTERN EXAMPLE EXPOSED METAL SHOWN SCALE:15X 0.07 MIN ALL AROUND 0.
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EXAMPLE STENCIL DESIGN RGH0016A WQFN - 0.8 mm max height PLASTIC QUAD FLATPACK - NO LEAD 4X ( 1.15) (0.675) TYP 16 13 17 16X (0.6) 1 12 (0.675) TYP 16X (0.25) SYMM (3.8) 12X (0.5) 9 4 EXPOSED METAL TYP 8 5 (R0.05) TYP SYMM (3.8) SOLDER PASTE EXAMPLE BASED ON 0.125 mm THICK STENCIL EXPOSED PAD 17 78% PRINTED SOLDER COVERAGE BY AREA UNDER PACKAGE SCALE:20X 4214978/B 01/2017 NOTES: (continued) 6. Laser cutting apertures with trapezoidal walls and rounded corners may offer better paste release.
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MECHANICAL DATA DNT0012B WSON - 0.8mm max height SON (PLASTIC SMALL OUTLINE - NO LEAD) SDA12B (Rev A) 4214928/A 03/2013 NOTES: 1. All linear dimensions are in millimeters. Dimensions in parenthesis are for reference only. Dimensioning and tolerancing per ASME Y14.5M. 2. This drawing is subject to change without notice. 3. This package is designed to be soldered to a thermal pad on the board for thermal and mechanical performance.
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