SNLS605C July   2018  – April 2024 DS90UB935-Q1

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
    6. 5.6 Recommended Timing for the Serial Control Bus
    7. 5.7 Timing Diagrams
    8. 5.8 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 CSI-2 Receiver
        1. 6.3.1.1 CSI-2 Receiver Operating Modes
        2. 6.3.1.2 CSI-2 Receiver High-Speed Mode
        3. 6.3.1.3 CSI-2 Protocol Layer
        4. 6.3.1.4 CSI-2 Short Packet
        5. 6.3.1.5 CSI-2 Long Packet
        6. 6.3.1.6 CSI-2 Errors and Detection
          1. 6.3.1.6.1 CSI-2 ECC Detection and Correction
          2. 6.3.1.6.2 CSI-2 Check Sum Detection
          3. 6.3.1.6.3 D-PHY Error Detection
          4. 6.3.1.6.4 CSI-2 Receiver Status
      2. 6.3.2 FPD-Link III Forward Channel Transmitter
        1. 6.3.2.1 Frame Format
      3. 6.3.3 FPD-Link III Back Channel Receiver
      4. 6.3.4 Serializer Status and Monitoring
        1. 6.3.4.1 Forward Channel Diagnostics
        2. 6.3.4.2 Back Channel Diagnostics
        3. 6.3.4.3 Voltage and Temperature Sensing
          1. 6.3.4.3.1 Programming Example
        4. 6.3.4.4 Built-In Self Test
      5. 6.3.5 FrameSync Operation
        1. 6.3.5.1 External FrameSync
        2. 6.3.5.2 Internally Generated FrameSync
      6. 6.3.6 GPIO Support
        1. 6.3.6.1 GPIO Status
        2. 6.3.6.2 GPIO Input Control
        3. 6.3.6.3 GPIO Output Control
        4. 6.3.6.4 Forward Channel GPIO
        5. 6.3.6.5 Back Channel GPIO
    4. 6.4 Device Functional Modes
      1. 6.4.1 Clocking Modes
        1. 6.4.1.1 Synchronous Mode
        2. 6.4.1.2 Non-Synchronous Clock Mode
        3. 6.4.1.3 Non-Synchronous Internal Mode
        4. 6.4.1.4 DVP Backwards Compatibility Mode
        5. 6.4.1.5 Configuring CLK_OUT
      2. 6.4.2 MODE
    5. 6.5 Programming
      1. 6.5.1 I2C Interface Configuration
        1. 6.5.1.1 CLK_OUT/IDX
          1. 6.5.1.1.1 IDX
      2. 6.5.2 I2C Interface Operation
      3. 6.5.3 I2C Timing
    6. 6.6 Pattern Generation
      1. 6.6.1 Reference Color Bar Pattern
      2. 6.6.2 Fixed Color Patterns
      3. 6.6.3 Packet Generator Programming
        1. 6.6.3.1 Determining Color Bar Size
      4. 6.6.4 Code Example for Pattern Generator
    7. 6.7 Register Maps
      1. 6.7.1 Main Registers
        1. 6.7.1.1  I2C Device ID Register
        2. 6.7.1.2  Reset
        3. 6.7.1.3  General Configuration
        4. 6.7.1.4  Forward Channel Mode Selection
        5. 6.7.1.5  BC_MODE_SELECT
        6. 6.7.1.6  PLL Clock Control
        7. 6.7.1.7  Clock Output Control 0
        8. 6.7.1.8  Clock Output Control 1
        9. 6.7.1.9  Back Channel Watchdog Control
        10. 6.7.1.10 I2C Control 1
        11. 6.7.1.11 I2C Control 2
        12. 6.7.1.12 SCL High Time
        13. 6.7.1.13 SCL Low Time
        14. 6.7.1.14 Local GPIO DATA
        15. 6.7.1.15 GPIO Input Control
        16. 6.7.1.16 DVP_CFG
        17. 6.7.1.17 DVP_DT
        18. 6.7.1.18 Force BIST Error
        19. 6.7.1.19 Remote BIST Control
        20. 6.7.1.20 Sensor Voltage Gain
        21. 6.7.1.21 Sensor Control 0
        22. 6.7.1.22 Sensor Control 1
        23. 6.7.1.23 Voltage Sensor 0 Thresholds
        24. 6.7.1.24 Voltage Sensor 1 Thresholds
        25. 6.7.1.25 Temperature Sensor Thresholds
        26. 6.7.1.26 CSI-2 Alarm Enable
        27. 6.7.1.27 Alarm Sense Enable
        28. 6.7.1.28 Back Channel Alarm Enable
        29. 6.7.1.29 CSI-2 Polarity Select
        30. 6.7.1.30 CSI-2 LP Mode Polarity
        31. 6.7.1.31 CSI-2 High-Speed RX Enable
        32. 6.7.1.32 CSI-2 Low Power Enable
        33. 6.7.1.33 CSI-2 Termination Enable
        34. 6.7.1.34 CSI-2 Packet Header Control
        35. 6.7.1.35 Back Channel Configuration
        36. 6.7.1.36 Datapath Control 1
        37. 6.7.1.37 Remote Partner Capabilities 1
        38. 6.7.1.38 Partner Deserializer ID
        39. 6.7.1.39 Target 0 ID
        40. 6.7.1.40 Target 1 ID
        41. 6.7.1.41 Target 2 ID
        42. 6.7.1.42 Target 3 ID
        43. 6.7.1.43 Target 4 ID
        44. 6.7.1.44 Target 5 ID
        45. 6.7.1.45 Target 6 ID
        46. 6.7.1.46 Target 7 ID
        47. 6.7.1.47 Target 0 Alias
        48. 6.7.1.48 Target 1 Alias
        49. 6.7.1.49 Target 2 Alias
        50. 6.7.1.50 Target 3 Alias
        51. 6.7.1.51 Target 4 Alias
        52. 6.7.1.52 Target 5 Alias
        53. 6.7.1.53 Target 6 Alias
        54. 6.7.1.54 Target 7 Alias
        55. 6.7.1.55 Back Channel Control
        56. 6.7.1.56 Revision ID
        57. 6.7.1.57 Device Status
        58. 6.7.1.58 General Status
        59. 6.7.1.59 GPIO Pin Status
        60. 6.7.1.60 BIST Error Count
        61. 6.7.1.61 CRC Error Count 1
        62. 6.7.1.62 CRC Error Count 2
        63. 6.7.1.63 Sensor Status
        64. 6.7.1.64 Sensor V0
        65. 6.7.1.65 Sensor V1
        66. 6.7.1.66 Sensor T
        67. 6.7.1.67 CSI-2 Error Count
        68. 6.7.1.68 CSI-2 Error Status
        69. 6.7.1.69 CSI-2 Errors Data Lanes 0 and 1
        70. 6.7.1.70 CSI-2 Errors Data Lanes 2 and 3
        71. 6.7.1.71 CSI-2 Errors Clock Lane
        72. 6.7.1.72 CSI-2 Packet Header Data
        73. 6.7.1.73 Packet Header Word Count 0
        74. 6.7.1.74 Packet Header Word Count 1
        75. 6.7.1.75 CSI-2 ECC
        76. 6.7.1.76 IND_ACC_CTL
        77. 6.7.1.77 IND_ACC_ADDR
        78. 6.7.1.78 IND_ACC_DATA
        79. 6.7.1.79 FPD3_TX_ID0
        80. 6.7.1.80 FPD3_TX_ID1
        81. 6.7.1.81 FPD3_TX_ID2
        82. 6.7.1.82 FPD3_TX_ID3
        83. 6.7.1.83 FPD3_TX_ID4
        84. 6.7.1.84 FPD3_TX_ID5
      2. 6.7.2 Indirect Access Registers
        1. 6.7.2.1 PATGEN Registers
        2. 6.7.2.2 Analog Registers
  8. 7 Application and Implementation
    1. 7.1 Application Information
      1. 7.1.1 Power-over-Coax
    2. 7.2 Typical Applications
      1. 7.2.1 Design Requirements
      2. 7.2.2 Detailed Design Procedure
        1. 7.2.2.1 CSI-2 Interface
        2. 7.2.2.2 FPD-Link III Input / Output
        3. 7.2.2.3 Internal Regulator Bypassing
        4. 7.2.2.4 Loop Filter Decoupling
      3. 7.2.3 Application Curve
    3. 7.3 Power Supply Recommendations
      1. 7.3.1 Power-Up Sequencing
        1. 7.3.1.1 System Initialization
          1. 7.3.1.1.1 Code Example for Temperature Ramp Initialization
      2. 7.3.2 Power Down (PDB)
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
        1. 7.4.1.1 CSI-2 Guidelines
      2. 7.4.2 Layout Examples
  9. 8 Device and Documentation Support
    1. 8.1 Documentation Support
      1. 8.1.1 Related Documentation
    2. 8.2 Receiving Notification of Documentation Updates
    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

Package Options

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

7.1.1 Power-over-Coax

The DS90UB935-Q1 is designed to support the Power-over-Coax (PoC) method of powering remote sensor systems. With this method, the power is delivered over the same medium (a coaxial cable) used for high-speed digital video data, bidirectional control, and diagnostics data transmission. This method uses passive networks or filters that isolate the transmission line from the loading of the DC-DC regulator circuits and the connecting power traces on both sides of the link as shown in Figure 7-1.

GUID-C3E442ED-BEA8-4B83-A9F2-19A7392AFDA0-low.gifFigure 7-1 Power-over-Coax (PoC) System Diagram

The PoC networks' impedance of ≥ 1kΩ over a specific frequency band is recommended to isolate the transmission line from the loading of the regulator circuits. Higher PoC network impedance contributes to favorable insertion loss and return loss characteristics in the high-speed channel. The lower limit of the frequency band is defined as ½ of the frequency of the back channel, fBC. The upper limit of the frequency band is the frequency of the forward high-speed channel, fFC. However, the main criteria that need to be met in the total high-speed channel, which consists of a serializer PCB, a deserializer PCB, and a cable, are the insertion loss and return loss limits defined in the Total Channel Requirements(1) over the entire system, while the system is under maximum current load and extreme temperature conditions (2).

  1. Contact TI for more information on the required Channel Specifications defined for each individual FPD-Link device.
  2. The PoC network and any components along the high-speed trace on the PCB contributes to the PCB loss budget. TI has recommendations for the loss budget allocation for each individual PCB and cable component in the overall high-speed channel, but the loss limits defined for the total channel in the Channel Specifications must be met.

Figure 7-2 shows an example PoC network designed for a "4G" FPD-Link III consisting of DS90UB935-Q1 and DS90UB936-Q1, DS90UB954-Q1, or DS90UB960-Q1 pair with the bidirectional channel operating at 50Mbps (½ fBCC = 25MHz.) and the forward channel operating at 4.16Gbps (fFC ≈ 2.1GHz). Other PoC networks are possible and can be different on the serializer and the deserializer boards as long as the printed-circuit board return loss requirements are met.

GUID-20240116-SS0I-69D2-PTK1-D4N58ZKM9QHW-low.svg Figure 7-2 Typical PoC Network for a "4G" FPD-Link III

Table 7-1 lists essential components for this particular PoC network. Note that the impedance characteristic of the ferrite beads deviates with the bias current. Therefore, keeping the current going through the network below 150mA is recommended.

Table 7-1 Suggested Components for a "4G" FPD-Link III PoC Network
COUNT REF DES DESCRIPTION PART NUMBER MFR
1 L1 Inductor, 10µH, 0.288Ω maximum, 530mA minimum (Isat, Itemp)
30MHz SRF minimum, 3mm × 3mm, General-Purpose		 LQH3NPN100MJR Murata
Inductor, 10µH, 0.288Ω maximum, 530mA minimum (Isat, Itemp)
30MHz SRF minimum, 3mm × 3mm, AEC-Q200		 LQH3NPZ100MJR Murata
Inductor, 10µH, 0.360Ω maximum, 450mA minimum (Isat, Itemp)
30MHz SRF minimum, 3.2mm × 2.5mm, AEC-Q200		 NLCV32T-100K-EFD TDK
Inductor, 10µH, 0.400Ω typical, 550mA minimum (Isat, Itemp)
39MHz SRF typical, 3mm × 3mm, AEC-Q200		 TYS3010100M-10 Laird
Inductor, 10µH, 0.325Ω maximum, 725mA minimum (Isat, Itemp)
41MHz SRF typical, 3mm × 3mm, AEC-Q200		 TYS3015100M-10 Laird
3 FB1-FB3 Ferrite Bead, 1.5kΩ at 1GHz, 0.5Ω maximum at DC
500mA at 85°C, 0603 SMD , General-Purpose		 BLM18HE152SN1 Murata
Ferrite Bead, 1.5kΩ at 1GHz, 0.5Ω maximum at DC
500mA at 85°C, 0603 SMD , AEC-Q200		 BLM18HE152SZ1 Murata

In addition to the selection of PoC network components, the placement and layout play a critical role as well.

  • Place the smallest component, typically a ferrite bead or a chip inductor, as close to the connector as possible. Route the high-speed trace through one of the pads to avoid stubs.
  • Use the smallest component pads as allowed by manufacturer's design rules. Add anti-pads in the inner planes below the component pads to minimize impedance drop.
  • Consult with the connector manufacturer for optimized connector footprint. If the connector is mounted on the same side as the IC, minimize the impact of the through-hole connector stubs by routing the high-speed signal traces on the opposite side of the connector mounting side.
  • Use coupled 100Ω differential signal traces from the device pins to the AC-coupling caps. Use 50Ω single-ended traces from the AC-coupling capacitors to the connector.
  • Terminate the inverting signal traces close to the connectors with standard 49.9Ω resistors.

The suggested characteristics for single-ended PCB traces (microstrips or striplines) for serializer or deserializer boards are listed in Table 7-2. The effects of the PoC networks must be accounted for when testing the traces for compliance to the suggested limits.

Table 7-2 Suggested Characteristics for Single-Ended PCB Traces With Attached PoC Networks
PARAMETERMINTYPMAXUNIT
LtraceSingle-ended PCB trace length from the device pin to the connector pin5cm
ZtraceSingle-ended PCB trace characteristic impedance455055Ω
ZconConnector (mounted) characteristic impedance405060Ω

The VPOC fluctuations on the serializer side, caused by the transient current draw of the sensor, the DC resistance of cables, and PoC components, must be kept to a minimum as well. Increasing the VPOC voltage and adding extra decoupling capacitance (> 10 µF) help reduce the amplitude and slew rate of the VPOC fluctuations.