SNAS461G May   2010  – November 2018 LM98640QML-SP

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and Functions
    1.     Pin Functions
  6. 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 Quality Conformance Inspection
    6. 6.6 LM98640QML-SP Electrical Characteristics
    7. 6.7 AC Timing Specifications
    8. 6.8 Typical Performance Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1 Input Sampling Modes
        1. 7.3.1.1 Sample & Hold Mode
          1. 7.3.1.1.1 Sample & Hold Mode CLAMP/SAMPLE Adjust
        2. 7.3.1.2 CDS Mode
          1. 7.3.1.2.1 CDS Mode Bimodal Offset
          2. 7.3.1.2.2 CDS Mode CLAMP/SAMPLE Adjust
      2. 7.3.2 Input Bias and Clamping
        1. 7.3.2.1 Sample and Hold Mode Biasing
        2. 7.3.2.2 CDS Mode Biasing
        3. 7.3.2.3 VCLP DAC
      3. 7.3.3 Programmable Gain
        1. 7.3.3.1 CDS/SH Stage Gain
        2. 7.3.3.2 PGA Gain Plots
      4. 7.3.4 Programmable Analog Offset Correction
      5. 7.3.5 Analog to Digital Converter
      6. 7.3.6 LVDS Output
        1. 7.3.6.1 LVDS Output Voltage
        2. 7.3.6.2 LVDS Output Modes
        3. 7.3.6.3 TXFRM Output
          1. 7.3.6.3.1 Output Mode 1 - Dual Lane
          2. 7.3.6.3.2 Output Mode 2 - Quad Lane
      7. 7.3.7 Clock Receiver
      8. 7.3.8 Power Trimming
    4. 7.4 Device Functional Mode
      1. 7.4.1 Powerdown Modes
      2. 7.4.2 LVDS Test Modes
        1. 7.4.2.1 Test Mode 0 - Fixed Pattern
        2. 7.4.2.2 Test Mode 1 - Horizontal Gradient
        3. 7.4.2.3 Test Mode 2 - Vertical Gradient
        4. 7.4.2.4 Test Mode 3 - Lattice Pattern
        5. 7.4.2.5 Test Mode 4 - Stripe Pattern
        6. 7.4.2.6 Test Mode 5 - LVDS Test Pattern (Synchronous)
        7. 7.4.2.7 Test Mode 6 - LVDS Test Pattern (Asynchronous)
        8. 7.4.2.8 Pseudo Random Number Mode
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
      2. 7.5.2 Writing to the Serial Registers
      3. 7.5.3 Reading the Serial Registers
      4. 7.5.4 Serial Interface Timing Details
    6. 7.6 Register Maps
      1. 7.6.1 Register Definitions
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Total Ionizing Dose
      2. 8.1.2 Single Event Latch-Up and Functional Interrupt
      3. 8.1.3 Single Event Effects
    2. 8.2 Typical Application
      1. 8.2.1 Sample/Hold Mode
    3. 8.3 Initialization Set Up
  9. 9 Layout
    1. 9.1 Layout Guidelines
      1. 9.1.1 Power Planes
      2. 9.1.2 Bypass Capacitors
      3. 9.1.3 Ground Plane
      4. 9.1.4 Thermal Management
  10. 10Device and Documentation Support
    1. 10.1 Device Support
      1. 10.1.1 Development Support
        1. 10.1.1.1 Evaluation Board
        2. 10.1.1.2 Register Programming Software
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Community Resources
    4. 10.4 Export Control Notice
    5. 10.5 Trademarks
    6. 10.6 Electrostatic Discharge Caution
    7. 10.7 Glossary
  11. 11Mechanical, Packaging, and Orderable Information
    1. 11.1 Engineering Samples

Package Options

Refer to the PDF data sheet for device specific package drawings

Mechanical Data (Package|Pins)
  • NBB|68
Thermal pad, mechanical data (Package|Pins)
Orderable Information

7.3.1.1.1 Sample & Hold Mode CLAMP/SAMPLE Adjust

For accurate sampling of the input signals the LM98640QML-SP allows for full adjustment of the internal SAMPLE pulse to align it to the proper positions over the input signal. In Sample & Hold mode the SAMPLE pulse should be placed over the pixel output period of the image sensor. Only the Sample Start and Sample End Registers (0x22,0x23) need to be configured, the Clamp Start and Clamp End Registers (0x20,0x21) are not valid in Sample & Hold Mode. Internally the input clock is divided into 64 edges per clock period, the Sample Start and Sample End Registers correspond to the internal edge number the SAMPLE pulse will start and end. To adjust the SAMPLE pulse, first send the CLAMP and SAMPLE signals to the DTM pins by writing 10 to bits[4:3] of the Clock Monitor Register (0x09). This will allow the user to observe the SAMPLE pulse on pin DTM1 along with the image sensor output using an oscilloscope. Then, using the Sample Start and End Registers, adjust the SAMPLE pulse to align it over the Video Level portion of the image sensor output. To allow for settling and to reduce noise, the SAMPLE pulse should be made as wide as possible and fill the entire Video Level portion of the input signal.

Figure 15 shows some examples of an input waveform and where the SAMPLE pulse should be placed. Ideally the image sensor output would line up directly with the input clock at the AFE inputs, but due to trace delays in the system the image sensor output is delayed relative to the input clock. In the delayed image sensor waveform the Sample Start value is higher than the Sample End value. In this situation the SAMPLE pulse will start in one clock period and wraps around to the next. This allows the LM98640QML-SP to adjust for the delay in the image sensor waveform. Notice that edge zero of the internal clock does not line up with the rising edge of the input clock. This is due to internal delays of the clock signals. The amount of delay can be calculated from operating frequency using the following formula: tDCLK = 6.0 ns + 3 / 64 × TINCLK

LM98640QML-SP 30064775.gifFigure 15. S/H Mode CLAMP/SAMPLE Adjust