SNOSCY0 March   2014 LDC1051

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Terminal Configuration and Functions
  6. 6 Specifications
    1. 6.1 Absolute Maximum Ratings
    2. 6.2 Handling Ratings
    3. 6.3 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Timing Requirements
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Inductive Sensing
      2. 7.3.2 Measuring Rp with LDC1051
    4. 7.4 Device Functional Modes
      1. 7.4.1 Power Modes
      2. 7.4.2 INTB terminal Modes
        1. 7.4.2.1 Comparator Mode
        2. 7.4.2.2 Wake-Up Mode
        3. 7.4.2.3 DRDYB Mode
    5. 7.5 Programming
      1. 7.5.1 SPI Description
        1. 7.5.1.1 Extended SPI Transactions
    6. 7.6 Register Map and Description
  8. 8 Applications and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Calculation of Rp_MIN and Rp_MAX
        1. 8.1.1.1 Setting Rp_MAX
        2. 8.1.1.2 Setting Rp_MIN
      2. 8.1.2 Output Data Rate
      3. 8.1.3 Choosing Filter Capacitor (CFA and CFB Terminals)
    2. 8.2 Typical Applications
      1. 8.2.1 Axial Distance Sensing Using a PCB Sensor with LDC1051
        1. 8.2.1.1 Design Requirements
        2. 8.2.1.2 Detailed Design Procedure
          1. 8.2.1.2.1 Sensor and Target
          2. 8.2.1.2.2 Calculating Sensor Capacitor
          3. 8.2.1.2.3 Choosing Filter Capacitor
          4. 8.2.1.2.4 Setting Rp_MIN and Rp_MAX
          5. 8.2.1.2.5 Calculating Minimum Sensor Frequency
        3. 8.2.1.3 Application Curves
      2. 8.2.2 Lateral Position Sensing Application Diagram
      3. 8.2.3 Angular Position Sensing Application Diagram
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Trademarks
    2. 11.2 Electrostatic Discharge Caution
    3. 11.3 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information

6 Specifications

6.1 Absolute Maximum Ratings

MIN MAX UNIT
Analog Supply Voltage (VDD – GND) 6 V
IO Supply Voltage (VIO – GND) 6 V
Voltage on any Analog Terminal –0.3 VDD + 0.3 V
Voltage on any Digital Terminal –0.3 VIO + 0.3 V
Input Current on INA and INB 8 mA
Junction Temperature, TJ 150 °C

6.2 Handling Ratings

MIN MAX UNIT
Tstg Storage Temperature range -65 150 °C
VESD Human Body Model (HBM) ESD stress voltage 1k 1k V
Charge Device Model (CDM) ESD stress voltage 250 250 V

6.3 Recommended Operating Conditions

over operating free-air temperature range (unless otherwise noted)
MIN MAX UNIT
Analog Supply Voltage (VDD – GND) 4.75 5.25 V
IO Supply Voltage (VIO – GND) 1.8 5.25 V
VDD-VIO 0 V
Operating Temperature, TA -40 125 °C

6.4 Thermal Information

THERMAL METRIC(1) NHR
(16-TERMINALS)		 UNIT
θJA Junction-to-ambient thermal resistance 28 °C/W
(1) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

6.5 Electrical Characteristics(1)

Unless otherwise specified, all limits ensured for TA = TJ = 25°C, VDD = 5 V, VIO = 3.3 V
PARAMETER TEST CONDITIONS MIN(3) TYP(2) MAX(3) UNIT
POWER
VDD Analog supply voltage 4.75 5 5.25 V
VIO IO supply voltage  VIO≤VDD 1.8 3.3 5.25 V
IDD Supply current, VDD Does not include sensor current.(4) 1.7 2.3 mA
IVIO IO supply current Static current 14 µA
IDD_LP Stand-by mode supply current 250 µA
tSTART Start-Up Time From POR to ready-to-convert. 2 ms
LDC
ƒsensor_MIN Minimum sensor frequency 5 kHz
ƒsensor_MAX Maximum sensor frequency 5 MHz
Asensor_MIN Minimum sensor amplitude 1 VPP
Asensor_MAX Maximum sensor amplitude 4 VPP
tREC Recovery time Oscillation start-up time after Rp under-range condition 10 1/fsensor
Rp Min Minimum sensor Rp range 798 Ω
Rp Max Maximum Sensor Rp range 3.93 MΩ
Rp Res Rp measurement resolution 8 Bits
tS_MIN Minimum response time Minimum programmable settling time of digital filter 192 × 1 / ƒsensor s
tS_MAX Maximum response time Maximum programmable settling time of digital filter 6144 × 1 / ƒsensor s
DIGITAL I/O CHARACTERISTICS
VIH Logic 1 input voltage 0.8 × VIO V
VIL Logic 0 input voltage 0.2 × VIO V
VOH Logic 1 output voltage ISOURCE = 400 µA VIO – 0.3 V
VOL Logic 0 output voltage ISINK = 400 µA 0.3 V
IIOHL Digital IO leakage current –500 500 nA
(1) Electrical Characteristics Table values apply only for factory testing conditions at the temperature indicated. Factory testing conditions result in very limited self-heating of the device such that TJ = TA. No specification of parametric performance is indicated in the electrical tables under conditions of internal self-heating where TJ > TA. Absolute Maximum Ratings indicate junction temperature limits beyond which the device may be permanently degraded, either mechanically or electrically.
(2) 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 specified on shipped production material.
(3) Limits are specified by testing, design, or statistical analysis at 25°C. Limits over the operating temperature range are specified through correlations using statistical quality control (SQC) method.
(4) LC tank current depends on the Q-factor of the tank, distance and material of the target.

6.6 Timing Requirements

Unless otherwise noted, all limits specified at TA = 25°C, VDD = 5, VIO = 3.3, 10 pF capacitive load in parallel with a 10 kΩ load on the SDO terminal. Specified by design; not production tested.
PARAMETER MIN TYP MAX UNIT
ƒSCLK Serial Clock Frequency 4 MHz
tPH SCLK Pulse Width High ƒSCLK = 4 MHz 0.4 / ƒSCLK s
tPL SCLK Pulse Width Low ƒSCLK = 4 MHz 0.4 / ƒSCLK s
tSU SDI Setup Time 10 ns
tH SDI Hold Time 10 ns
tODZ SDO Driven-to-Tristate Time Measured at 10% / 90% point 20 ns
tOZD SDO Tristate-to-Driven Time Measured at 10% / 90% point 20 ns
tOD SDO Output Delay Time 20 ns
tCSS CSB Setup Time 20 ns
tCSH CSB Hold Time 20 ns
tIAG Inter-Access Gap 100 ns
tDRDYB Data ready pulse width Data ready pulse at every 1 / ODR if no data is read 1 / ƒsensor s

Unless otherwise noted, all limits specified at TA = 25°C, VDD=5.0, VIO=3.3, 10pF capacitive load in parallel with a 10kΩ load on SDO. Specified by design; not production tested.

td_write_snoscx2.gifFigure 1. Write Timing Diagram
td_read_snoscx2.gifFigure 2. Read Timing Diagram

6.7 Typical Characteristics

C002_snoscy1.png
A.
Sensor Details: Table 16 Rp_MIN: 1.347 kΩ
Target Material: Stainless Steel Rp_MAX: 38.785 kΩ
Figure 3. Rp vs Distance
C003_snoscy1.png
A.
Sensor Details: Table 16 Rp_MIN: 1.347 kΩ
Target Material: Stainless Steel Rp_MAX: 38.785 kΩ
Figure 4. Proximity Data vs Distance