SLWS207B May   2008  – January 2016 ADS5560 , ADS5562


  1. Features
  2. Applications
  3. Description
  4. Revision History
  5. Pin Configuration and Functions
  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
    6. 6.6  AC Electrical Characteristics for ADS5560 Fs = 40 MSPS
    7. 6.7  AC Electrical Characteristics for ADS5562, Fs = 80 MSPS
    8. 6.8  Electrical Characteristics for ADS5562
    9. 6.9  Electrical Characteristics for ADS5560
    10. 6.10 Digital Characteristics
    11. 6.11 Timing Characteristics for LVDS and CMOS Modes
    12. 6.12 Serial Interface Timing Characteristics
    13. 6.13 Reset Timing
    14. 6.14 Timing Characteristics at Lower Sampling Frequencies
    15. 6.15 Typical Characteristics
      1. 6.15.1 ADS5562 - 80 MSPS
      2. 6.15.2 ADS5560 - 40 MSPS
      3. 6.15.3 Valid Up to Max Clock Rate (ADS5562 or ADS5560)
  7. Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Low-Frequency Noise Suppression
      2. 7.3.2 Analog Input Circuit
        1. Drive Circuit Recommendations
        2. Example Driving Circuit
        3. Input Common-Mode
        4. Programmable Fine Gain
    4. 7.4 Device Functional Modes
      1. 7.4.1 Low Sampling Frequency Operation
      2. 7.4.2 Clock Input
        1. Power-Down
          1. Global STANDBY
          2. Output Buffer Disable
          3. Input Clock Stop
        2. Power Supply Sequence
      3. 7.4.3 Output Interface
        1. DDR LVDS Outputs
        2. LVDS Buffer Current Programmability
        3. LVDS Buffer Internal Termination
        4. Parallel CMOS
        5. Output Clock Position Programmability
      4. 7.4.4 Output Data Format
      5. 7.4.5 Reference
        1. Internal Reference
        2. External Reference
    5. 7.5 Programming
      1. 7.5.1 Device Programming Modes
      2. 7.5.2 Using Parallel Interface Control Only
        1. Using Serial Interface Programming Only
        2. Using Both Serial Interface And Parallel Controls
        3. Description of Parallel Pins
      3. 7.5.3 Serial Interface
      4. 7.5.4 Register Initialization
    6. 7.6 Register Maps
      1. 7.6.1 Register Description
  8. Application and Implementation
    1. 8.1 Application Information
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. Clocking Source for ADC5562
        2. Amplifier Selection
      3. 8.2.3 Application Curve
  9. Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
      1. 10.1.1 Supply Decoupling
      2. 10.1.2 Exposed Thermal Pad
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Device Support
      1. 11.1.1 Device Nomenclature
    2. 11.2 Documentation Support
      1. 11.2.1 Related Documentation
    3. 11.3 Related Links
    4. 11.4 Community Resources
    5. 11.5 Trademarks
    6. 11.6 Electrostatic Discharge Caution
    7. 11.7 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

10 Layout

10.1 Layout Guidelines

Figure 62 is a section of the layout of the ADS5562 that illustrates good layout practices for the clocking, analog input, and digital outputs. In this example, the analog input enters from the left while the clocking enters from the top, keeping the clock signal away from the analog signals so as to not allow coupling between the analog signal and the clock signal. On the layout of the differential traces, note the symmetry of the trace routing between the two sides of the differential signals.

The digital outputs are routed off to the right, so as to keep the digital signals away from the analog inputs and away from the clock. Note the circuitous routing added to some of the LVDS differential traces but not to others; this is the equalize the lengths of the routing across all of the LVDS traces so as to preserve the setup/hold timing at the end of the digital signal routings. If the timing closure in the receiving device (such as an FPGA or ASIC) has enough timing margin, then the circuitous routing to equalize trace lengths may not be necessary.

In addition, the solid gray areas are ground planes, providing more isolation between the clocking and the analog inputs as well as between the clocking and the digital outputs.

10.1.1 Supply Decoupling

As ADS556x already includes internal decoupling, minimal external decoupling can be used without loss in performance. Decoupling capacitors can help to filter external power supply noise, so the optimum number of capacitors would depend on the actual application. The decoupling capacitors should be placed very close to the converter supply pins. TI recommends using separate supplies for the analog and digital supply pins to isolate digital switching noise from sensitive analog circuitry. In case only a single 3.3-V supply is available, it should be routed first to AVDD. The supply can then be tapped and isolated with a ferrite bead (or inductor) with decoupling capacitor, before being routed to DRVDD.

10.1.2 Exposed Thermal Pad

The exposed pad must be soldered at the bottom of the package to a ground plane for best thermal performance. For detailed information, see the TI application notes, QFN Layout Guidelines (SLOA122) and QFN/SON PCB Attachment (SLUA271).

10.2 Layout Example

ADS5560 ADS5562 layout_slws207.gif Figure 62. Typical Layout of ADS5562