SNOSBI3C July   2000  – October 2018 LF198-N , LF298 , LF398-N

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Connection
      2.      Acquisition Time
  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 Recommended Operating Conditions
    3. 6.3 Thermal Information
    4. 6.4 Electrical Characteristics, LF198-N and LF298
    5. 6.5 Electrical Characteristics, LF198A-N
    6. 6.6 Electrical Characteristics, LF398-N
    7. 6.7 Electrical Characteristics, LF398A-N (OBSOLETE)
    8. 6.8 Typical Characteristics
  7. 7 Parameter Measurement Information
    1. 7.1 TTL and CMOS 3 V ≤ VLOGIC (Hi State) ≤ 7 V
    2. 7.2 CMOS 7 V ≤ VLOGIC (Hi State) ≤ 15 V
    3. 7.3 Operational Amplifier Drive
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Hold Capacitor
      2. 9.1.2 DC and AC Zeroing
      3. 9.1.3 Logic Rise Time
      4. 9.1.4 Sampling Dynamic Signals
      5. 9.1.5 Digital Feedthrough
    2. 9.2 Typical Applications
      1. 9.2.1  X1000 Sample and Hold
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
        3. 9.2.1.3 Application Curves
      2. 9.2.2  Sample and Difference Circuit
      3. 9.2.3  Ramp Generator With Variable Reset Level
      4. 9.2.4  Integrator With Programmable Reset Level
      5. 9.2.5  Output Holds at Average of Sampled Input
      6. 9.2.6  Increased Slew Current
      7. 9.2.7  Reset Stabilized Amplifier
      8. 9.2.8  Fast Acquisition, Low Droop Sample and Hold
      9. 9.2.9  Synchronous Correlator for Recovering Signals Below Noise Level
      10. 9.2.10 2-Channel Switch
      11. 9.2.11 DC and AC Zeroing
      12. 9.2.12 Staircase Generator
      13. 9.2.13 Differential Hold
      14. 9.2.14 Capacitor Hysteresis Compensation
  10. 10Power Supply Recommendations
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Device Support
      1. 12.1.1 Device Nomenclature
    2. 12.2 Related Links
    3. 12.3 Community Resources
    4. 12.4 Trademarks
    5. 12.5 Electrostatic Discharge Caution
    6. 12.6 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

8.4 Device Functional Modes

The LFx98x devices have a sample mode and hold mode controlled by the LOGIC voltage relative to the LOGIC REFERENCE voltage. The device is in sample mode when the LOGIC input is pulled high relative to the LOGIC REFERENCE voltage and in hold mode when the LOGIC input is pulled low relative to the LOGIC REFERENCE. In sample mode, the output is tracking the input signal by charging and discharging the hold capacitor. Smaller values of hold capacitance will allow the output to track faster signals. In hold mode the input signal is disconnected from the signal path and the output retains the value on the hold capacitor. Larger values of capacitance will have a smaller droop rate as shown in Figure 4.