SNAS647D February   2015  – March 2016 TDC7200

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Companion Device
  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 Timing Requirements
    7. 7.7 Switching Characteristics
    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 LDO
      2. 8.3.2 CLOCK
      3. 8.3.3 Counters
        1. 8.3.3.1 Coarse and Clock Counters Description
        2. 8.3.3.2 Coarse and Clock Counters Overflow
        3. 8.3.3.3 Clock Counter STOP Mask
        4. 8.3.3.4 ENABLE
    4. 8.4 Device Functional Modes
      1. 8.4.1 Calibration
      2. 8.4.2 Measurement Modes
        1. 8.4.2.1 Measurement Mode 1
          1. 8.4.2.1.1 Calculating Time-of-Flight (Measurement Mode 1)
        2. 8.4.2.2 Measurement Mode 2
          1. 8.4.2.2.1 Calculating Time-of-Flight (TOF) (Measurement Mode 2)
      3. 8.4.3 Timeout
      4. 8.4.4 Multi-Cycle Averaging
      5. 8.4.5 START and STOP Edge Polarity
      6. 8.4.6 Measurement Sequence
      7. 8.4.7 Wait Times for TDC7200 Startup
    5. 8.5 Programming
      1. 8.5.1 Serial Peripheral Interface (SPI)
        1. 8.5.1.1 CSB
        2. 8.5.1.2 SCLK
        3. 8.5.1.3 DIN
        4. 8.5.1.4 DOUT
        5. 8.5.1.5 Register Read/Write
        6. 8.5.1.6 Auto Increment Mode
    6. 8.6 Register Maps
      1. 8.6.1  Register Initialization
      2. 8.6.2  CONFIG1: Configuration Register 1 R/W (address = 00h) [reset = 0h]
      3. 8.6.3  CONFIG2: Configuration Register 2 R/W (address = 01h) [reset = 40h]
      4. 8.6.4  INT_STATUS: Interrupt Status Register (address = 02h) [reset = 00h]
      5. 8.6.5  INT_MASK: Interrupt Mask Register R/W (address = 03h) [reset = 07h]
      6. 8.6.6  COARSE_CNTR_OVF_H: Coarse Counter Overflow High Value Register (address = 04h) [reset = FFh]
      7. 8.6.7  COARSE_CNTR_OVF_L: Coarse Counter Overflow Low Value Register (address = 05h) [reset = FFh ]
      8. 8.6.8  CLOCK_CNTR_OVF_H: Clock Counter Overflow High Register (address = 06h) [reset = FFh]
      9. 8.6.9  CLOCK_CNTR_OVF_L: Clock Counter Overflow Low Register (address = 07h) [reset = FFh]
      10. 8.6.10 CLOCK_CNTR_STOP_MASK_H: CLOCK Counter STOP Mask High Value Register (address = 08h) [reset = 00h]
      11. 8.6.11 CLOCK_CNTR_STOP_MASK_L: CLOCK Counter STOP Mask Low Value Register (address = 09h) [reset = 00h]
      12. 8.6.12 TIME1: Time 1 Register (address: 10h) [reset = 00_0000h]
      13. 8.6.13 CLOCK_COUNT1: Clock Count Register (address: 11h) [reset = 00_0000h]
      14. 8.6.14 TIME2: Time 2 Register (address: 12h) [reset = 00_0000h]
      15. 8.6.15 CLOCK_COUNT2: Clock Count Register (address: 13h) [reset = 00_0000h]
      16. 8.6.16 TIME3: Time 3 Register (address: 14h) [reset = 00_0000h]
      17. 8.6.17 CLOCK_COUNT3: Clock Count Registers (address: 15h) [reset = 00_0000h]
      18. 8.6.18 TIME4: Time 4 Register (address: 16h) [reset = 00_0000h]
      19. 8.6.19 CLOCK_COUNT4: Clock Count Register (address: 17h) [reset = 00_0000h]
      20. 8.6.20 TIME5: Time 5 Register (address: 18h) [reset = 00_0000h]
      21. 8.6.21 CLOCK_COUNT5: Clock Count Register (address: 19h) [reset = 00_0000h]
      22. 8.6.22 TIME6: Time 6 Register (address: 1Ah) [reset = 00_0000h]
      23. 8.6.23 CALIBRATION1: Calibration 1 Register (address: 1Bh ) [reset = 00_0000h]
      24. 8.6.24 CALIBRATION2: Calibration 2 Register (address: 1Ch ) [reset = 00_0000h]
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
        1. 9.2.2.1 Flow Meter Regulations and Accuracy
        2. 9.2.2.2 Transmit Time in Ultrasonic Flow Meters
        3. 9.2.2.3 ΔTOF Accuracy Requirement Calculation
      3. 9.2.3 Application Curves
    3. 9.3 Post Filtering Recommendations
    4. 9.4 CLOCK Recommendations
      1. 9.4.1 CLOCK Accuracy
      2. 9.4.2 CLOCK Jitter
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Community Resources
    3. 12.3 Trademarks
    4. 12.4 Electrostatic Discharge Caution
    5. 12.5 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

7 Specifications

7.1 Absolute Maximum Ratings

TA = 25°C , VDD = 3.3V, GND = 0V (unless otherwise noted).(1)(2)(3)
MIN MAX UNIT
VDD Supply voltage –0.3 3.9 V
VI Terminal input voltage –0.3 VDD+0.3 V
VDIFF_IN |Voltage differential| between any two input terminals 3.9 V
VIN_GND_VDD |Voltage differential| between any input terminal and GND or VDD 3.9 V
II Input current at any pin –5 5 mA
TA Ambient temperature -40 125 °C
Tstg Storage temperature –65 150 °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) The algebraic convention, whereby the most negative value is a minimum and the most positive value is a maximum
(3) All voltages are with respect to ground, unless otherwise specified.

7.2 ESD Ratings

VALUE UNIT
V(ESD) Electrostatic discharge Human-body model (HBM), per ANSI/ESDA/JEDEC JS-001(1) ±1000 V
Charged-device model (CDM), per JEDEC specification JESD22-C101(2) ±250
(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

TA = 25°C , VDD = 3.3V, GND = 0V (unless otherwise noted).
MIN NOM MAX UNIT
VDD Supply voltage 2 3.6 V
VI Terminal voltage 0 VDD V
VIH Voltage input high 0.7 × VDD 3.6 V
VIL Voltage input low 0 0.3 × VDD V
FCALIB_CLK Frequency (Reference/Calibration Clock) 1 (1) 8 16 MHz
DUTYCLOCK Input clock duty cycle 50%
TIMING REQUIREMENTS: Measurement Mode 1 (1)
T1STARTSTOP_Min Minimum Time between Start and Stop Signal 12 ns
T1STOPSTOP_Min Minimum Time between 2 Stop Signals 67 ns
T1STARTSTOP_Max Maximum time bet. Start and Stop Signal 500 ns
T1STOPSTOP_Max Maximum time bet. Start and last Stop Signal 500 ns
TIMING REQUIREMENTS: Measurement 2 (1)
T2STARTSTOP_Min Minimum Time between Start and Stop Signal 2×tCLOCK s
T2STOPSTOP_Min Minimum Time between 2 Stop Signals 2×tCLOCK s
T2STARTSTOP_Max Maximum time bet. Start and Stop Signal (216-2)×tCLOCK s
T2STOPSTOP_Max Maximum. time bet. Start and last Stop Signal (216-2)×tCLOCK s
TIMING REQUIREMENTS: ENABLE INPUT
TREN Rise Time for Enable Signal (20%-80%) 1 to 100 ns
TFEN Fall Time for Enable Signal (20%-80%) 1 to 100 ns
TIMING REQUIREMENTS: START, STOP, CLOCK
TRST, TFST Maximum rise, fall time for START, STOP signals (20%-80%) 1 ns
TRXCLK, TFXCLK Maximum rise, fall time for external CLOCK (20%-80%) 1 ns
TIMING REQUIREMENTS: TRIGG
TTRIGSTART Time from TRIG to START 5 ns
TEMPERATURE
TA Ambient temperature –40 85 °C
TJ Junction temperature –40 85 °C

7.4 Thermal Information

THERMAL METRIC(2) TDC7200 UNIT
PW [TSSOP]
14 PINS
RθJA Junction-to-ambient thermal resistance 134.9 °C/W
RθJC(top) Junction-to-case (top) thermal resistance 63
RθJB Junction-to-board thermal resistance 76.8
ψJT Junction-to-top characterization parameter 12.4
ψJB Junction-to-board characterization parameter 76.2
θJA Package thermal impedance 113
(1) Specified by design.
(2) For more information about traditional and new thermal metrics, see the IC Package Thermal Metrics application report, SPRA953.

7.5 Electrical Characteristics

TA = 25°C , VDD = 3.3 V, GND = 0 V (unless otherwise noted).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
TDC CHARACTERISTICS
LSB Resolution Single shot measurement 55 ps
TACC-2 Accuracy (Mode 2) (1) CLOCK = 8 MHz 28 ps
TSTD-2 Standard Deviation (Mode 2) Measured time = 100 µs 50 ps
Measured time = 1 µs 35 ps
OUTPUT CHARACTERISTICS: TRIGG, INTB, DOUT
VOH Output voltage high Isource = -2 mA 2.31 2.95 V
VOL Output voltage low Isink = 2 mA 0.35 0.99 V
INPUT CHARACTERISTICS: ENABLE, START, STOP, CLOCK, DIN, CSB,SCLK
Cin Input capacitance (2) 3 pF
POWER CONSUMPTION (see Measurement Mode 1 and Measurement Mode 2)
Ish Shutdown current EN = LOW 0.3 2 µA
IQA Quiescent Current A EN = HIGH; TDC running 1.35 mA
IQB Quiescent Current B EN = HIGH; TDC OFF, Clock Counter running 71 µA
IQC Quiescent Current C EN = HIGH; measurement stopped, SPI communication only 87 µA
IQD Quiescent Current D EN = HIGH, TDC OFF, counter stopped, no communication 50 µA

7.6 Timing Requirements

MIN NOM MAX UNIT
TIMING REQUIREMENTS: START, STOP INPUTS, CLOCK
PWSTART Pulse width for Start Signal 10 ns
PWSTOP Pulse width for Stop Signal 10 ns
SERIAL INTERFACE TIMING CHARACTERISTICS (VDD = 3.3 V, fSCLK = 20 MHz) (See Figure 1)
fSCLK SCLK Frequency 20 MHz
t1 SCLK period 50 ns
t2 SCLK High Time 16 ns
t3 SCLK Low Time 16 ns
t4 DIN setup time 4 ns
t5 DIN hold time 4 ns
t6 CSB fall to SCLK rise 6 ns
t7 Last SCLK rising edge to CSB rising edge 6 ns
t8 Minimum pause time (CSB high) 40 ns
t9 Clk fall to DOUT bus transition 12 ns
(1) Accuracy is defined as the systematic error in the output signal; the error of the device excluding noise.
(2) Specified by design.

7.7 Switching Characteristics

TA = 25°C , VDD = 3.3 V, GND = 0 V (unless otherwise noted).
PARAMETER TEST CONDITIONS MIN TYP MAX UNIT
WAKE UP TIME
TWAKEUP_PERIOD Time to be ready for Measurement LSB within 0.3% of settled value 300 µs
TDC7200 SPI timing diagram v3.png Figure 1. SPI Register Write: 8 bit Register Example

7.8 Typical Characteristics

TA = 25°C , VDD = 3.3 V, GND = 0 V, CLOCK = 8 MHz, CALIBRATION2_PERIODS = 10, AVG_CYCLES = 1 Measurement, NUM_STOP = Single STOP, Measurement Mode 2 (unless otherwise noted).
TDC7200 D001_SNAS647.gif
Figure 2. Time-of-Flight (TOF) vs. VDD (Measurement Mode 2)
TDC7200 D004_SNAS647.gif
Figure 4. TOF vs. VDD (Measurement Mode 1)
TDC7200 D006_SNAS647.gif
Figure 6. Resolution (LSB) vs. VDD
TDC7200 D008_SNAS647.gif
Figure 8. Operating Current (IQA) vs. VDD
TDC7200 D010_SNAS647.gif
Figure 10. Shutdown Current (ISH) vs. VDD
TDC7200 D012_SNAS647.gif
Figure 12. Operating Currents (IQB, IQC, IQD) vs. Temperature
TDC7200 D014_SNAS647.png
Figure 14. Standard Time-of-Flight Histogram (Normalized)
TDC7200 D002_SNAS647.gif
Figure 3. TOF vs. Temperature (Measurement Mode 2)
TDC7200 D005_SNAS647.gif
Figure 5. TOF vs. Temperature (Measurement Mode 1)
TDC7200 D007_SNAS647.gif
Figure 7. Resolution (LSB) vs. Temperature
TDC7200 D009_SNAS647.gif
Figure 9. Operating Currents (IQB, IQC, IQD) vs. VDD
TDC7200 D011_SNAS647.gif
Figure 11. Operating Current (IQA) vs. Temperature
TDC7200 D013_SNAS647.gif
Figure 13. Shutdown Current (ISH) vs. Temperature