SNOSD01D May   2015  – October  2016 LDC1101

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Simplified Schematic
  5. 5 Revision History
  6. 6 Pin Configuration and Functions
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Digital Interface
    7. 7.7 Timing Requirements
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Sensor Driver
    4. 8.4 Device Functional Modes
      1. 8.4.1 Measurement Modes
      2. 8.4.2 RP+L Measurement Mode
        1. 8.4.2.1 RPMIN and RPMAX
        2. 8.4.2.2 Programmable Internal Time Constants
        3. 8.4.2.3 RP+L Mode Measurement Sample Rate
      3. 8.4.3 High Resolution L (LHR) Measurement Mode
      4. 8.4.4 Reference Count Setting
      5. 8.4.5 L-Only Measurement Operation
      6. 8.4.6 Minimum Sensor Frequency and Watchdog Setting
      7. 8.4.7 Low Power Modes
        1. 8.4.7.1 Shutdown Mode
        2. 8.4.7.2 Sleep Mode
      8. 8.4.8 Status Reporting
      9. 8.4.9 Switch Functionality and INTB Reporting
    5. 8.5 Programming
      1. 8.5.1 SPI Programming
    6. 8.6 Register Maps
      1. 8.6.1  Individual Register Listings
      2. 8.6.2  Register RP_SET (address = 0x01) [reset = 0x07]
      3. 8.6.3  Register TC1 (address = 0x02) [reset = 0x90]
      4. 8.6.4  Register TC2 (address = 0x03) [reset = 0xA0]
      5. 8.6.5  Register DIG_CONF (address = 0x04) [reset = 0x03]
      6. 8.6.6  Register ALT_CONFIG (address = 0x05) [reset = 0x00]
      7. 8.6.7  Register RP_THRESH_HI_LSB (address = 0x06) [reset = 0x00]
      8. 8.6.8  Register RP_THRESH_HI_MSB (address = 0x07) [reset = 0x00]
      9. 8.6.9  Register RP_THRESH_LO_LSB (address = 0x08) [reset = 0x00]
      10. 8.6.10 Register RP_THRESH_LO_MSB (address = 0x09) [reset = 0x00]
      11. 8.6.11 Register INTB_MODE (address = 0x0A) [reset = 0x00]
      12. 8.6.12 9.Register START_CONFIG (address = 0x0B) [reset = 0x01]
      13. 8.6.13 Register D_CONFIG (address = 0x0C) [reset = 0x00]
      14. 8.6.14 Register L_THRESH_HI_LSB (address = 0x16) [reset = 0x00]
      15. 8.6.15 Register L_THRESH_HI_MSB (address = 0x17) [reset = 0x00]
      16. 8.6.16 Register L_THRESH_LO_LSB (address = 0x18) [reset = 0x00]
      17. 8.6.17 Register L_THRESH_LO_MSB (address = 0x19) [reset = 0x00]
      18. 8.6.18 Register STATUS (address = 0x020 [reset = 0x00]
      19. 8.6.19 Register RP_DATA_LSB (address = 0x21) [reset = 0x00]
      20. 8.6.20 Register RP_DATA_MSB (address = 0x22) [reset = 0x00]
      21. 8.6.21 Register L_DATA_LSB (address = 0x23) [reset = 0x00]
      22. 8.6.22 Register L_DATA_MSB (address = 0x24) [reset = 0x00]
      23. 8.6.23 Register LHR_RCOUNT_LSB (address = 0x30) [reset = 0x00]
      24. 8.6.24 Register LHR_RCOUNT_MSB (address = 0x31) [reset = 0x00]
      25. 8.6.25 Register LHR_OFFSET_LSB (address = 0x32) [reset = 0x00]
      26. 8.6.26 Register LHR_OFFSET_MSB (address = 0x33) [reset = 0x00]
      27. 8.6.27 Register LHR_CONFIG (address = 0x34) [reset = 0x00]
      28. 8.6.28 Register LHR_DATA_LSB (address = 0x38) [reset = 0x00]
      29. 8.6.29 Register LHR_DATA_MID (address = 0x39) [reset = 0x00]
      30. 8.6.30 Register LHR_DATA_MSB (address = 0x3A) [reset = 0x00]
      31. 8.6.31 Register LHR_STATUS (address = 0x3B) [reset = 0x00]
      32. 8.6.32 Register RID (address = 0x3E) [reset = 0x02]
      33. 8.6.33 Register DEVICE_ID (address = 0x3F) [reset = 0xD4]
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1  TI Designs and Application Notes
      2. 9.1.2  Theory of Operation
      3. 9.1.3  RP+L Mode Calculations
      4. 9.1.4  LDC1101 RP Configuration
      5. 9.1.5  Setting Internal Time Constant 1
      6. 9.1.6  Setting Internal Time Constant 2
      7. 9.1.7  MIN_FREQ and Watchdog Configuration
      8. 9.1.8  RP+L Sample Rate Configuration With RESP_TIME
      9. 9.1.9  High Resolution Inductance Calculation (LHR mode)
      10. 9.1.10 LHR Sample Rate Configuration With RCOUNT
      11. 9.1.11 Setting RPMIN for LHR Measurements
      12. 9.1.12 Sensor Input Divider
      13. 9.1.13 Reference Clock Input
      14. 9.1.14 INTB Reporting on SDO
      15. 9.1.15 DRDY (Data Ready) Reporting on SDO
      16. 9.1.16 Comparator Functionality
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Device Configuration for RP+L Measurement with an Example Sensor
        2. 9.2.2.2 Device Configuration for LHR Measurement with an Example Sensor
      3. 9.2.3 Application Curves
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
      1. 11.1.1 Ground and Power Planes
      2. 11.1.2 CLKIN Routing
      3. 11.1.3 Capacitor Placement
      4. 11.1.4 Sensor Connections
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Development Support
    2. 12.2 Documentation Support
      1. 12.2.1 Related Documentation
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

7 Specifications

7.1 Absolute Maximum Ratings

over operating free-air temperature range (unless otherwise noted)(1)
MIN MAX UNIT
VDD Supply voltage range 3.6 V
Vi Voltage on INA, INB –0.3 2.3 V
Voltage on CLDO –0.3 1.9 V
Voltage on any other pin(2) –0.3 VDD + 0.3 V
TJ Junction temperature –55 125 °C
Tstg Storage temperature –65 125 °C
(1) Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. These are stress ratings only, which do not imply functional operation of the device at these or any other conditions beyond those indicated under Recommended Operating Conditions. Exposure to absolute-maximum-rated conditions for extended periods may affect device reliability.
(2) Maximum voltage across any two pins is VDD+0.3.

7.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±2000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±1000
(1) JEDEC document JEP155 states that 500-V HBM allows safe manufacturing with a standard ESD control process.
(2) JEDEC document JEP157 states that 250-V CDM allows safe manufacturing with a standard ESD control process.

7.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN NOM MAX UNIT
VDD Supply voltage 1.71 3.46 V
TJ Junction temperature –40 125 °C

7.4 Thermal Information

THERMAL METRIC(1) LDC1101 UNIT
DRC (VSON)
10 PINS
RθJA Junction-to-ambient thermal resistance 44.2 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 50.1 °C/W
RθJB Junction-to-board thermal resistance 19.6 °C/W
ψJT Junction-to-top characterization parameter 0.7 °C/W
ψJB Junction-to-board characterization parameter 19.8 °C/W
RθJC(bot) Junction-to-case (bottom) thermal resistance 4.4 °C/W
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

Over recommended operating conditions unless otherwise noted. VDD = 1.8 V, TA = 25°C.
PARAMETER TEST CONDITION(1) MIN(2) TYP(3) MAX(2) UNIT
POWER
VDD Supply voltage 1.71 3.46 V
IDD Supply current START_CONFIG= 0x00, no sensor connected 1.9 2.7 mA
IDDS Supply current including sensor current ƒCLKIN = 16 MHz, ƒSENSOR = 2 MHz,
START_CONFIG = 0x00		 3.2 mA
IDDSL Sleep mode supply current START_CONFIG =0x01 135 180 µA
ISD Shutdown mode supply current 1.4 6.7 µA
SENSOR
RP Measurement part-to-part variation RESP_TIME= 6144, D_CONFIG=0x00, ALT_CONFIG=0x00, START_CONFIG = 0x00, ƒSENSOR = 2 MHz 1%
ISENSORMAX Sensor maximum current drive RP_MIN = b111, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 0.598 0.6 0.602 mA
ISENSORMIN Sensor minimum current drive RP_MAX = b000, HIGH_Q_SENSOR=b0, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 4.7 µA
ƒSENSOR Sensor resonant frequency Device settings and Sensor compliant as detailed in LDC1101 RP Configuration 0.5 10 MHz
RPRES RP Measurement resolution 16 bits
LRES Inductance sensing resolution – RP+L Mode 16 bits
Inductance sensing resolution – LHR Mode 24 bits
AOSC Sensor oscillation amplitude INA – INB, START_CONFIG=0x00, D_CONFIG=0x00, ALT_CONFIG=0x00 1.2 VPP
DETECTION
tS_MIN Minimum response time (RP+L mode) RP+L Mode, RESP_TIME=b010 192
÷ ƒSENSOR		 s
tS_MAX Maximum response time (RP+L mode) RP+L Mode, RESP_TIME=b111 6144
÷ ƒSENSOR		 s
Ts_MAX High Res L maximum measurement interval LHR_REF_COUNT=0xFFFF, START_CONFIG=0x00 (220+39)
÷ ƒCLKIN		 s
SRMAXRP RP+L Mode maximum sample rate ƒCLKIN=16 MHz, ƒSENSOR = 10 MHz, RESP_TIME=b010 156.25 kSPS
SRMAXL High Res L Mode maximum sample rate High Resolution L Mode, LHR_REF_COUNT=0x0002, ƒCLKIN=16 MHz 183.8 kSPS
FREQUENCY REFERENCE
fCLKIN Reference input frequency 1 16 MHz
DCfin Reference duty cycle 40% 60%
VIH Input high voltage (Logic “1”) 0.8 × VDD V
VIL Input low voltage (Logic “0”) 0.2 × VDD V
(1) Register values are represented as either binary (b is the prefix to the digits), or hexadecimal (0x is the prefix to the digits). Decimal values have no prefix.
(2) Limits are ensured by testing, design, or statistical analysis at 25°C. Limits over the operating temperature range are ensured through correlation using statistical quality control (SQC) method.
(3) Typical values represent the most likely parametric norm as determined at the time of characterization. Actual typical values may vary over time and will also depend on the application and configuration. The typical values are not tested and are not verified on shipped production material.

7.6 Digital Interface

PARAMETER MIN TYP MAX UNIT
VOLTAGE LEVELS
VIH Input high voltage (Logic “1”) 0.8 × VDD V
VIL Input low voltage (Logic “0”) 0.2 × VDD V
VOH Output high voltage (Logic “1”, ISOURCE = 400 µA) VDD– 0.3 V
VOL Output low voltage (Logic “0”, ISINK = 400 µA) 0.3 V
IOHL Digital IO leakage current –500 500 nA

7.7 Timing Requirements

See Figure 1 and Figure 2.
MIN NOM MAX UNIT
tSTART Start-up time from shutdown to sleep 0.8 ms
tWAKE Wake-up time (from completion of SPI to conversion start; does not include sensor settling time) 0.04 ms
INTERFACE TIMING REQUIREMENTS(1)
ƒSCLK Serial clock frequency 8 MHz
twH SCLK pulse-width high 0.4/ƒSCLK s
twL SCLK pulse-width low 0.4/ƒSCLK s
tsu SDI setup time 10 ns
th SDI hold time 10 ns
tODZ SDO driven-to-tristate time 25 ns
tOZD SDO tristate-to-driven time 25 ns
tOD SDO output delay time 20 ns
tsu(CS) CSB setup time 20 ns
th(CS) CSB hold time 20 ns
tIAG CSB inter-access interval 100 ns
tw(DRDY) Data ready pulse width 1/ƒSENSOR ns
(1) Unless otherwise noted, all limits specified at TA = 25°C, VDD = 1.8 V, 10-pF capacitive load in parallel with a 10-kΩ load on the SDO pin. Specified by design; not production tested.
LDC1101 write_timing_diagram_snosd01.gif Figure 1. Write Timing Diagram
LDC1101 read_timing_diagram_snosd01.gif Figure 2. Read Timing Diagram

7.8 Typical Characteristics

LDC1101 D001_idd_vs_temperature_SNOSD01.gif
Not including sensor current, default register settings.
Figure 3. IDD vs Temperature
LDC1101 D003_supply_current_vs_fclkin_SNOSD01.gif
Including sensor current. 13-mm diameter sensor 0.1-mm spacing/0.1-mm trace width/ 4-layer 28 turns, fSENSOR = 2 MHz, RP_SET = 0x07, TX1 = 0x50, TC2 = 0x80, RCOUNT = 0xFFFF, RESP_TIME = 6144
Figure 5. Supply Current (mA) vs ƒCLKIN (MHz) at 25°C
LDC1101 D005_idd_sleep_mode_vs_vdd_SNOSD01.gif
Figure 7. IDD Sleep Mode vs VDD
LDC1101 D007_idd_shutdown_vs_vdd_SNOSD01.gif
Figure 9. IDD Shutdown vs VDD
LDC1101 D009_isensormin_vs_vdd_SNOSD01.gif
RP_SET.RPMAX = b000
Figure 11. ISENSOR-MIN vs VDD
LDC1101 D002_idd_vs_vdd_SNOSD01.gif
Not including sensor current, default register settings.
Figure 4. IDD vs VDD
LDC1101 D004_idd_sleep_mode_vs_temperature_SNOSD01.gif
Figure 6. IDD Sleep Mode vs Temperature
LDC1101 D006_idd_shutdown_vs_temperature_SNOSD01.gif
Figure 8. IDD Shutdown vs Temperature
LDC1101 D008_isensormax_vs_vdd_SNOSD01.gif
RP_SET.RPMIN = b111
Figure 10. ISENSOR-MAX vs VDD