SLAS748G March   2011  – January 2024 DAC3482

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1  Absolute Maximum Ratings
    2. 5.2  ESD Ratings
    3. 5.3  Recommended Operating Conditions
    4. 5.4  Thermal Information
    5. 5.5  Electrical Characteristics – DC Specifications
    6. 5.6  Electrical Characteristics – Digital Specifications
    7. 5.7  Electrical Characteristics – AC Specifications
    8. 5.8  Electrical Characteristics - Phase-Locked Loop Specifications
    9. 5.9  Timing Requirements - Digital Specifications
    10. 5.10 Switching Characteristics – AC Specifications
    11. 5.11 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1  Serial Interface
      2. 6.3.2  Data Interface
        1. 6.3.2.1 Word-Wide Format
        2. 6.3.2.2 Byte-Wide Format
      3. 6.3.3  Input FIFO
      4. 6.3.4  FIFO Modes of Operation
        1. 6.3.4.1 Dual Sync Source Mode
        2. 6.3.4.2 Single Sync Source Mode
        3. 6.3.4.3 Bypass Mode
      5. 6.3.5  Clocking Modes
        1. 6.3.5.1 PLL Bypass Mode
        2. 6.3.5.2 PLL Mode
      6. 6.3.6  FIR Filters
      7. 6.3.7  Complex Signal Mixer
        1. 6.3.7.1 Full Complex Mixer
        2. 6.3.7.2 Coarse Complex Mixer
        3. 6.3.7.3 Mixer Gain
        4. 6.3.7.4 Real Channel Upconversion
      8. 6.3.8  Quadrature Modulation Correction (QMC)
        1. 6.3.8.1 Gain and Phase Correction
        2. 6.3.8.2 Offset Correction
        3. 6.3.8.3 Group Delay Correction
      9. 6.3.9  Temperature Sensor
      10. 6.3.10 Data Pattern Checker
      11. 6.3.11 Parity Check Test
        1. 6.3.11.1 Word-by-Word Parity
        2. 6.3.11.2 Block Parity
      12. 6.3.12 DAC3482 Alarm Monitoring
      13. 6.3.13 LVPECL Inputs
      14. 6.3.14 LVDS Inputs
      15. 6.3.15 Unused LVDS Port Termination
      16. 6.3.16 CMOS Digital Inputs
      17. 6.3.17 Reference Operation
      18. 6.3.18 DAC Transfer Function
      19. 6.3.19 Analog Current Outputs
    4. 6.4 Device Functional Modes
      1. 6.4.1 Multi-Device Synchronization
        1. 6.4.1.1 Multi-Device Synchronization: PLL Bypassed with Dual Sync Sources Mode
        2. 6.4.1.2 Multi-Device Synchronization: PLL Enabled with Dual Sync Sources Mode
        3. 6.4.1.3 Multi-Device Operation: Single Sync Source Mode
    5. 6.5 Programming
      1. 6.5.1 Power-Up Sequence
      2. 6.5.2 Example Start-Up Routine
        1. 6.5.2.1 Device Configuration
        2. 6.5.2.2 PLL Configuration
        3. 6.5.2.3 NCO Configuration
        4. 6.5.2.4 Example Start-Up Sequence
    6. 6.6 Register Map
      1. 6.6.1 Register Descriptions
        1. 6.6.1.1  Register Name: config0 – Address: 0x00, Default: 0x049C
        2. 6.6.1.2  Register Name: config1 – Address: 0x01, Default: 0x050E
        3. 6.6.1.3  Register Name: config2 – Address: 0x02, Default: 0x7000
        4. 6.6.1.4  Register Name: config3 – Address: 0x03, Default: 0xF000
        5. 6.6.1.5  Register Name: config4 – Address: 0x04, Default: No RESET Value (WRITE TO CLEAR)
        6. 6.6.1.6  Register Name: config5 – Address: 0x05, Default: Setup and Power-Up Conditions Dependent (WRITE TO CLEAR)
        7. 6.6.1.7  Register Name: config6 – Address: 0x06, Default: No RESET Value (READ ONLY)
        8. 6.6.1.8  Register Name: config7 – Address: 0x07, Default: 0xFFFF
        9. 6.6.1.9  Register Name: config8 – Address: 0x08, Default: 0x0000 (CAUSES AUTO-SYNC)
        10. 6.6.1.10 Register Name: config9 – Address: 0x09, Default: 0x8000
        11. 6.6.1.11 Register Name: config10 – Address: 0x0A, Default: 0x0000
        12. 6.6.1.12 Register Name: config11 – Address: 0x0B, Default: 0x0000
        13. 6.6.1.13 Register Name: config12 – Address: 0x0C, Default: 0x0400
        14. 6.6.1.14 Register Name: config13 – Address: 0x0D, Default: 0x0400
        15. 6.6.1.15 Register Name: config14 – Address: 0x0E, Default: 0x0400
        16. 6.6.1.16 Register Name: config15 – Address: 0x0F, Default: 0x0400
        17. 6.6.1.17 Register Name: config16 – Address: 0x10, Default: 0x0000 (CAUSES AUTO-SYNC)
        18. 6.6.1.18 Register Name: config17 – Address: 0x11, Default: 0x0000
        19. 6.6.1.19 Register Name: config18 – Address: 0x12, Default: 0x0000 (CAUSES AUTO-SYNC)
        20. 6.6.1.20 Register Name: config19 – Address: 0x13, Default: 0x0000
        21. 6.6.1.21 Register Name: config20 – Address: 0x14, Default: 0x0000
        22. 6.6.1.22 Register Name: config21 – Address: 0x15, Default: 0x0000
        23. 6.6.1.23 Register name: config22 – Address: 0x16, Default: 0x0000
        24. 6.6.1.24 Register Name: config23 – Address: 0x17, Default: 0x0000
        25. 6.6.1.25 Register Name: config24 – Address: 0x18, Default: NA
        26. 6.6.1.26 Register Name: config25 – Address: 0x19, Default: 0x0440
        27. 6.6.1.27 Register Name: config26 – Address: 0x1A, Default: 0x0020
        28. 6.6.1.28 Register Name: config27 – Address: 0x1B, Default: 0x0000
        29. 6.6.1.29 Register Name: config28 – Address: 0x1C, Default: 0x0000
        30. 6.6.1.30 Register Name: config29 – Address: 0x1D, Default: 0x0000
        31. 6.6.1.31 Register Name: config30 – Address: 0x1E, Default: 0x1111
        32. 6.6.1.32 Register Name: config31 – Address: 0x1F, Default: 0x1140
        33. 6.6.1.33 Register Name: config32 – Address: 0x20, Default: 0x2400
        34. 6.6.1.34 Register Name: config33 – Address: 0x21, Default: 0x0000
        35. 6.6.1.35 Register Name: config34 – Address: 0x22, Default: 0x1B1B
        36. 6.6.1.36 Register Name: config35 – Address: 0x23, Default: 0xFFFF
        37. 6.6.1.37 Register Name: config36 – Address: 0x24, Default: 0x0000
        38. 6.6.1.38 Register Name: config37 – Address: 0x25, Default: 0x7A7A
        39. 6.6.1.39 Register Name: config38 – Address: 0x26, Default: 0xB6B6
        40. 6.6.1.40 Register Name: config39 – Address: 0x27, Default: 0xEAEA
        41. 6.6.1.41 Register Name: config40 – Address: 0x28, Default: 0x4545
        42. 6.6.1.42 Register Name: config41 – Address: 0x29, Default: 0x1A1A
        43. 6.6.1.43 Register Name: config42 – Address: 0x2A, Default: 0x1616
        44. 6.6.1.44 Register Name: config43 – Address: 0x2B, Default: 0xAAAA
        45. 6.6.1.45 Register Name: config44 – Address: 0x2C, Default: 0xC6C6
        46. 6.6.1.46 Register Name: config45 – Address: 0x2D, Default: 0x0004
        47. 6.6.1.47 Register Name: config46 – Address: 0x2E, Default: 0x0000
        48. 6.6.1.48 Register Name: config47 – Address: 0x2F, Default: 0x0000
        49. 6.6.1.49 Register Name: config48 – Address: 0x30, Default: 0x0000
        50. 6.6.1.50 Register Name: version– Address: 0x7F, Default: 0x540C (READ ONLY)
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 IF Based LTE Transmitter
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
          1. 7.2.1.2.1 Data Input Rate
          2. 7.2.1.2.2 Interpolation
          3. 7.2.1.2.3 LO Feedthrough and Sideband Correction
        3. 7.2.1.3 Application Curves
      2. 7.2.2 Direct Upconversion (Zero IF) LTE Transmitter
        1. 7.2.2.1 Design Requirements
        2. 7.2.2.2 Detailed Design Procedure
          1. 7.2.2.2.1 Data Input Rate
          2. 7.2.2.2.2 Interpolation
          3. 7.2.2.2.3 LO Feedthrough and Sideband Correction
        3. 7.2.2.3 Application Curves
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Examples
      3. 7.4.3 Assembly
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Device Nomenclature
        1. 8.1.1.1 Definition of Specifications
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Support Resources
    4. 8.4 Trademarks
    5. 8.5 Electrostatic Discharge Caution
    6. 8.6 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information
    1. 10.1 Clarifications for DAC3482 Power Supply and Phase-Locked Loop Specification

Package Options

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

6.3.15 Unused LVDS Port Termination

In byte-wide data interface format, the data is transferred via the D[7:0]P/N LVDS port and the D[15:8]P/N LVDS port are not active. The non-active, unused pins can be left unconnected (floating) or connected to a nominal, differential LVDS active HIGH or active LOW voltage. The choice of LVDS connections to the unused LVDS ports will not affect the operations of LVDS receiver, digital functions such as mixers, NCO, and QMC, and analog output stage. However, if the system designer wishes to implement the following features in the end system, the designer may need to connect the unused ports to a known logic value:

  • During system prototyping stage, the designer may perform timing analysis and data transfer error checking on the LVDS ports using the DAC3482 data pattern checker functionality.
  • The DAC3482 has parity check feature for continuous validity monitoring of data transfer. Both word-by-word parity and block parity requires known logic values on the unused LVDS ports.

The following example allows the termination of the unused LVDS ports to a known logic HIGH value. As shown in Figure 6-35, The design involves the connection to the DIGVDD rail and one RSET resistor to bias the positive terminals of unused LVDS ports to be 1.2V and negative terminals of unused LVDS ports to 1V. The design keeps the minimum common mode input voltage of the LVDS input to be above 1V, and keeps the differential LVDS voltage to be 200mV. Since the design expects the differential voltage on the unused ports to be static, the differential LVDS voltage can be as low as 100mV to maintain a logic HIGH. Refer to Section 5.6 for details of LVDS Input requirements.

GUID-DE53CC74-1E5B-46C3-830C-F50722BF8687-low.gifFigure 6-35 Unused LVDS Ports Connected to Static Logic High Differential Voltage
  1. Connect the positive terminals of unused LVDS ports in parallel to DIGVDD supply at 1.2 V nominal. For instance, connect D[15:8] positive pins together to DIGVDD.
  2. Connect the negative terminals of unused LVDS ports in parallel to a RSET resistor to ground.
  3. The REQ value is the equivalent, parallel resistance of the on-chip termination for all the unused LVDS ports. In byte wide data interface format, eight ports were unused, therefore, the REQ is eight parallel ZT. Worst case ZT value of 135 Ω is used in the design to account for the lowest possible current IEQ and the worst case common mode on the negative LVDS terminals. Another analysis will be performed with ZT value of 85 Ω for worst case differential LVDS voltages.
  4. With Ohm’s Law, the following equation describes the relationship between RSET and REQ.
    Equation 13. GUID-0FE80E48-0851-4538-8D3E-C508910D3DA0-low.gif
  5. With REQ of eight parallel, 135Ω ZT (or 16.875Ω equivalent), RSET is 84.5Ω with standard 1% resistor value. IEQ is approximately 11.8 mA. The expected voltage at negative terminals of LVDS ports is approximately 1V. The differential LVDS voltage is 200mV.
  6. With same RSET of 84.5Ω, if the REQ has dropped to eight parallel, 85Ω ZT (or 10.625Ω equivalent), IEQ is approximately 12.6mA. The expected voltage at negative terminals of LVDS port is approximately 1.06V. The differential LVDS voltage is 138mV. As long as the static LVDS differential voltage is above 100mV, the LVDS port will register a logic HIGH value for the data.

Depending on the DAC3482 functionality required, additional unused LVDS ports such as FRAMEP/N, SYNCP/N, or PARITYP/N can also be left unconnected (floating) or connected to a nominal, differential LVDS active HIGH or active LOW voltage. The usage of these ports depends mainly on the FIFO synchronization settings and parity checking settings. The unused FRAMEP/N, SYNCP/N, or PARITYP/N ports can be connected in parallel with the unused LVDS data port with adjustments to the RSET resistor value.