SLASEA3D December   2016  – December 2023 DAC38RF80 , DAC38RF83 , DAC38RF84 , DAC38RF85 , DAC38RF90 , DAC38RF93

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Device Comparison
  6. 5 Pin Configuration and Functions
  7. 6 Specifications
    1. 6.1  Absolute Maximum Ratings
    2. 6.2  ESD Ratings
    3. 6.3  Recommended Operating Conditions
    4. 6.4  Thermal Information
    5. 6.5  Electrical Characteristics - DC Specifications
    6. 6.6  Electrical Characteristics - Digital Specifications
    7. 6.7  Electrical Characteristics - AC Specifications
    8. 6.8  PLL/VCO Electrical Characteristics
    9. 6.9  Timing Requirements
    10. 6.10 Typical Characteristics
  8. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagrams
    3. 7.3 Feature Description
      1. 7.3.1  SerDes Inputs
      2. 7.3.2  SerDes Rate
      3. 7.3.3  SerDes PLL
      4. 7.3.4  SerDes Equalizer
      5. 7.3.5  JESD204B Descrambler
      6. 7.3.6  JESD204B Frame Assembly
      7. 7.3.7  SYNC Interface
      8. 7.3.8  Single or Dual Link Configuration
      9. 7.3.9  Multi-Device Synchronization
      10. 7.3.10 SYSREF Capture Circuit
      11. 7.3.11 SerDes Test Modes through Serial Programming
      12. 7.3.12 SerDes Test Modes through IEEE 1500 Programming
      13. 7.3.13 Error Counter
      14. 7.3.14 Eye Scan
      15. 7.3.15 JESD204B Pattern Test
      16. 7.3.16 Multiband DUC (multi-DUC)
        1. 7.3.16.1 Multi-DUC input
        2. 7.3.16.2 Interpolation Filters
        3. 7.3.16.3 JESD204B Modes, Interpolation and Clock phase Programming
        4. 7.3.16.4 Digital Quadrature Modulator
        5. 7.3.16.5 Low Power Coarse Resolution Mixing Modes
        6. 7.3.16.6 Inverse Sinc Filter
        7. 7.3.16.7 Summation Block for Dual DUC Modes
      17. 7.3.17 PA Protection Block
      18. 7.3.18 Gain Block
      19. 7.3.19 Output Summation
      20. 7.3.20 Output Delay
      21. 7.3.21 Polarity Inversion
      22. 7.3.22 Temperature Sensor
      23. 7.3.23 Alarm Monitoring
      24. 7.3.24 Differential Clock Inputs
      25. 7.3.25 CMOS Digital Inputs
      26. 7.3.26 DAC Fullscale Output Current
      27. 7.3.27 Current Steering DAC Architecture
      28. 7.3.28 DAC Transfer Function for DAC38RF83, 93, 85
      29. 7.3.29 DAC Transfer Function for DAC38RF80/90/84
    4. 7.4 Device Functional Modes
      1. 7.4.1 Clocking Modes
      2. 7.4.2 PLL Bypass Mode Programming
      3. 7.4.3 Internal PLL/VCO
      4. 7.4.4 CLKOUT
      5. 7.4.5 Serial Peripheral Interface (SPI)
        1. 7.4.5.1 NORMAL (RW)
        2. 7.4.5.2 WRITE_TO_CLEAR (W0C)
        3. 7.4.5.3 Writing to Reserved Bits
    5. 7.5 Register Maps
      1. 7.5.1  Chip Reset and Configuration Register (address = 0x00) [reset = 0x5803]
      2. 7.5.2  IO Configuration Register (address = 0x01) [reset = 0x1800]
      3. 7.5.3  Lane Single Detect Alarm Mask Register (address = 0x02) [reset = 0xFFFF]
      4. 7.5.4  Clock Alarms Mask Register (address = 0x03) [reset = 0xFFFF
      5. 7.5.5  SERDES Loss of Signal Detection Alarms Register (address = 0x04) [reset = 0x0000]
      6. 7.5.6  SYSREF Alignment Circuit Alarms Register (address = 0x05) [reset = variable]
      7. 7.5.7  Temperature Sensor and PLL Loop Voltage Register (address = 0x06) [reset = variable]
      8. 7.5.8  Page Set Register (address = 0x09) [reset = 0x0000]
      9. 7.5.9  SYSREF Align to r1 and r3 Count Register (address = 0x78) [reset = 0x0000]
      10. 7.5.10 SYSREF Phase Count 1 and 2 Register (address = 0x79) [reset = 0x0000]
      11. 7.5.11 SYSREF Phase Count 3 and 4 Register (address = 0x7A) [reset = 0x0000]
      12. 7.5.12 Vendor ID and Chip Version Register (address = 0x7F) [reset = 0x0009]
      13. 7.5.13 Multi-DUC Configuration (PAP, Interpolation) Register (address = 0x0A) [reset = 0x02B0]
      14. 7.5.14 Multi-DUC Configuration (Mixers) Register (address = 0x0C) [reset = 0x2402]
      15. 7.5.15 JESD FIFO Control Register (address = 0x0D)[reset = 0x8000]
      16. 7.5.16 Alarm Mask 1 Register (address = 0x0E) [reset = 0x00FF]
      17. 7.5.17 Alarm Mask 2 Register (address = 0x0F) [reset = 0xFFFF]
      18. 7.5.18 Alarm Mask 3 Register (address = 0x10) [reset = 0xFFFF]
      19. 7.5.19 Alarm Mask 4 Register (address = 0x11) [reset = 0xFFFF]
      20. 7.5.20 JESD Lane Skew Register (address = 0x12) [reset = 0x0000]
      21. 7.5.21 CMIX Configuration Register (address = 0x17) [reset = 0x0000]
      22. 7.5.22 Output Summation and Delay Register (address = 0x19) [reset = 0x0000]
      23. 7.5.23 NCO Phase Path AB Register (address = 0x1C) [reset = 0x0000]
      24. 7.5.24 NCO Phase Path CD Register (address = 0x1D) [reset = 0x0000]
      25. 7.5.25 NCO Frequency Path AB Register (address = 0x1E-0x20) [reset = 0x0000 0000 0000]
      26. 7.5.26 NCO Frequency Path CD Register (address = 0x21-0x23) [reset = 0x0000 0000 0000]
      27. 7.5.27 SYSREF Use for Clock Divider Register (address = 0x24) [reset = 0x0010]
      28. 7.5.28 Serdes Clock Control Register (address = 0x25) [reset = 0x7700]
      29. 7.5.29 Sync Source Control 1 Register (address = 0x27) [reset = 0x1144]
      30. 7.5.30 Sync Source Control 2 Register (address = 0x28) [reset = 0x0000]
      31. 7.5.31 PAP path AB Gain Attenuation Step Register (address = 0x29) [reset = 0x0000]
      32. 7.5.32 PAP path AB Wait Time Register (address = 0x2A) [reset = 0x0000]
      33. 7.5.33 PAP path CD Gain Attenuation Step Register (address = 0x2B) [reset = 0x0000]
      34. 7.5.34 PAP Path CD Wait Time Register (address = 0x2C) [reset = 0x0000]
      35. 7.5.35 PAP path AB Configuration Register (address = 0x2D) [reset = 0x0FFF]
      36. 7.5.36 PAP path CD Configuration Register (address = 0x2E) [reset = 0x0FFF]
      37. 7.5.37 DAC SPI Configuration Register (address = 0x2F) [reset = 0x0000]
      38. 7.5.38 DAC SPI Constant Register (address = 0x30) [reset = 0x0000]
      39. 7.5.39 Gain for path AB Register (address = 0x32) [reset = 0x0400]
      40. 7.5.40 Gain for path CD Register (address = 0x33) [reset = 0x0400]
      41. 7.5.41 JESD Error Counter Register (address = 0x41) [reset = 0x0000]
      42. 7.5.42 JESD ID 1 Register (address = 0x46) [reset = 0x0044]
      43. 7.5.43 JESD ID 2 Register (address = 0x47) [reset = 0x190A]
      44. 7.5.44 JESD ID 3 and Subclass Register (address = 0x48) [reset = 0x31C3]
      45. 7.5.45 JESD Lane Enable Register (address = 0x4A) [reset = 0x0003]
      46. 7.5.46 JESD RBD Buffer and Frame Octets Register (address = 0x4B) [reset = 0x1300]
      47. 7.5.47 JESD K and L Parameters Register (address = 0x4C) [reset = 0x1303]
      48. 7.5.48 JESD M and S Parameters Register (address = 0x4D) [reset = 0x0100]
      49. 7.5.49 JESD N, HD and SCR Parameters Register (address = 0x4E) [reset = 0x0F4F]
      50. 7.5.50 JESD Character Match and Other Register (address = 0x4F) [reset = 0x1CC1]
      51. 7.5.51 JESD Link Configuration Data Register (address = 0x50) [reset = 0x0000]
      52. 7.5.52 JESD Sync Request Register (address = 0x51) [reset = 0x00FF]
      53. 7.5.53 JESD Error Output Register (address = 0x52) [reset = 0x00FF]
      54. 7.5.54 JESD ILA Check 1 Register (address = 0x53) [reset = 0x0100]
      55. 7.5.55 JESD ILA Check 2 Register (address = 0x54) [reset = 0x8E60]
      56. 7.5.56 JESD SYSREF Mode Register (address = 0x5C) [reset = 0x0001]
      57. 7.5.57 JESD Crossbar Configuration 1 Register (address = 0x5F) [reset = 0x0123]
      58. 7.5.58 JESD Crossbar Configuration 2 Register (address = 0x60) [reset = 0x4567]
      59. 7.5.59 JESD Alarms for Lane 0 Register (address = 0x64) [reset = 0x0000]
      60. 7.5.60 JESD Alarms for Lane 1 Register (address = 0x65) [reset = 0x0000]
      61. 7.5.61 JESD Alarms for Lane 2 Register (address = 0x66) [reset = 0x0000]
      62. 7.5.62 JESD Alarms for Lane 3 Register (address = 0x67) [reset = 0x0000]
      63. 7.5.63 JESD Alarms for Lane 4 Register (address = 0x68) [reset = 0x0000]
      64. 7.5.64 JESD Alarms for Lane 5 Register (address = 0x69) [reset = 0x0000]
      65. 7.5.65 JESD Alarms for Lane 6 Register (address = 0x6A [reset = 0x0000]
      66. 7.5.66 JESD Alarms for Lane 7 Register (address = 0x6B) [reset = 0x0000]
      67. 7.5.67 SYSREF and PAP Alarms Register (address = 0x6C) [reset = 0x0000]
      68. 7.5.68 Clock Divider Alarms 1 Register (address = 0x6D) [reset = 0x0000]
      69. 7.5.69 Clock Configuration Register (address = 0x0A) [reset = 0xFC03]
      70. 7.5.70 Sleep Configuration Register (address = 0x0B) [reset = 0x0022]
      71. 7.5.71 Divided Output Clock Configuration Register (address = 0x0C) [reset = 0x2002]
      72. 7.5.72 DAC Fullscale Current Register (address = 0x0D) [reset = 0xF000]
      73. 7.5.73 Internal SYSREF Generator Register (address = 0x10) [reset = 0x0000]
      74. 7.5.74 Counter for Internal SYSREF Generator Register (address = 0x11) [reset = 0x0000]
      75. 7.5.75 SPI SYSREF for Internal SYSREF Generator Register (address = 0x12) [reset = 0x0000]
      76. 7.5.76 Digital Test Signals Register (address = 0x1B) [reset = 0x0000]
      77. 7.5.77 Sleep Pin Control Register (address = 0x23) [reset = 0xFFFF]
      78. 7.5.78 SYSREF Capture Circuit Control Register (address = 0x24) [reset = 0x1000]
      79. 7.5.79 Clock Input and PLL Configuration Register (address = 0x31) [reset = 0x0200]
      80. 7.5.80 PLL Configuration 1 Register (address = 0x32) [reset = 0x0308]
      81. 7.5.81 PLL Configuration 2 Register (address = 0x33) [reset = 0x4018]
      82. 7.5.82 LVDS Output Configuration Register (address = 0x34) [reset = 0x0000]
      83. 7.5.83 Fuse Farm clock divider Register (address = 0x35) [reset = 0x0018]
      84. 7.5.84 Serdes Clock Configuration Register (address = 0x3B) [reset = 0x1802]
      85. 7.5.85 Serdes PLL Configuration Register (address = 0x3C) [reset = 0x8228]
      86. 7.5.86 Serdes Configuration 1 Register (address = 0x3D) [reset = 0x0x0088]
      87. 7.5.87 Serdes Configuration 2 Register (address = 0x3E) [reset = 0x0x0909]
      88. 7.5.88 Serdes Polarity Control Register (address = 0x3F) [reset = 0x0000]
      89. 7.5.89 JESD204B SYNCB OUTPUT Register (address = 0x76) [reset = 0x0000]
  9. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Start-up Sequence
    2. 8.2 Typical Application: Multi-band Radio Frequency Transmitter
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Calculating the JESD204B SerDes Rate
        2. 8.2.2.2 Calculating valid JESD204B SYSREF Frequency
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
      1. 8.3.1 Power Supply Sequencing
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  10. 9 Device and Documentation Support
    1. 9.1 Receiving Notification of Documentation Updates
    2. 9.2 Support Resources
    3. 9.3 Trademarks
    4. 9.4 Electrostatic Discharge Caution
    5. 9.5 Glossary
  11. 10Revision History
  12. 11Mechanical, Packaging, and Orderable Information

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • AAV|144
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.17 PA Protection Block

The DAC38RFxx incorporates an optional power amplifier protection (PAP) block to monitor when the input signal is two large, for example when an interface error occurs, and reduces the output signal power of the DAC. The PAP block achieves the functionality of reducing the input signal that crosses the threshold through three main sub-blocks. These are PAP trigger generation block, PAP gain state machine and GAIN block.

The PAP block keeps track of the input signal power by maintaining a sliding window accumulation of last N samples. N is selectable to be 32, 64 or 128 based on the setting (Table 7-39) of fields PAPAB_SEL_DLY in register PAP_CFG_AB (7.5.35) and PAPCD_SEL_DLY in register PAP_CFG_CD (7.5.36). The average amplitude of input signal is computed by dividing accumulated value by the number of samples in the delay-line (N). The result is then compared against the threshold in fields PAPAB_THRESH in register PAP_CFG_AB (7.5.35) and PAPCD_THRESH in register PAP_CFG_CD (7.5.36). If the threshold is violated, gain state machine is triggered which generated gain value to ramp down the DAC output signal amplitude. After the input signal returns to normal value, the state machine ramps up the DAC output signal amplitude.

Table 7-39 PAP Delay Line Selection
pap_sel_dly[1:0]# of samples averaged
0032
0164
10128
11Reserved

The generation of the PAP trigger as explained as follows:

  • The I and Q samples are treated separately – either can trigger attenuation
  • In dual DUC modes, each IQ pair is treated separately and has a separate gain block
  • 8 samples at the input are put through an absolute value circuit (all 2’s complement)
  • Next these values are vector summed to get a 12 bit result
  • Then 12 bit result is placed into the delay line and summed into the accumulator
  • The accumulator is also subtracting out the delayed 12 bit word corresponding to N = 32, N = 64 or N = 128
  • Finally the accumulator output is divided down by N and rounded to 13 bits. These 13 bits are compared to the threshold in the SPI registers. A pap_trig occurs if the threshold is exceeded.

The PAP gain state machine generates the pap gain value to be applied on the output stream to reduce the output signal amplitude. The state machine below is used to control the attenuation of the DAC output and the gaining up of the signal again once the trigger is released.

GUID-95F085CC-6432-4528-9285-CAB93928F986-low.gifFigure 7-24 PAP Gain State Machine

The normal operating condition for the PAP block is the NORMAL state in Figure 7-24. However, when the PAP block detects an error condition it sets the pap_trig signal to ‘1’ causing a state transition from NORMAL operation to the ATTENUATE state.

In the ATTENUTATE state the data path gain is scaled from 1.0 down to 0.0 by a programmable step amount set by fields PAPAB_GAIN_STEP in register PAP_GAIN_AB (7.5.31) and PAPCD_GAIN_STEP in register PAP_GAIN_CD (7.5.33). This value is always positive with the decimal place located between the MSB and MSB-1. Unity is equal to “1000000000”. Each clock cycle (16 samples) the PAP_GAIN is stepped down by PAPAB_GAIN_STEP and PAPCD_GAIN_STEP until the gain is 0.

After PAP_GAIN is 0, the state machine moves on to the WAIT state. Here a programmable counter counts clock cycles to allow the condition for the pap_trig to be fixed. Fields PAPAB_WAIT in register PAP_WAIT_AB (7.5.32) and PAPCD_WAIT in register PAP_WAIT_CD (7.5.34) are used to select the number of clock cycles (samples = 16 x PAPAB_WAIT or 16 x PAPCD_WAIT) to wait before moving to the next state. Once the WAIT counter equals zero and pap_trig=’0’, the state machine moves on to the GAIN state. If the WAIT equals 0 but pap_trig still equals ‘1’ then the state machine stays in the WAIT state until pap_trig =’0’.