SCDA008C June   2021  – November 2021 CD4052B , TS3A225E , TS3A44159

 

  1.   Trademarks
  2. 1Introduction
  3. 2Semiconductor Switches
    1. 2.1 NMOS Switch
    2. 2.2 PMOS Switch
  4. 3Basic Signal-Switch Structures
    1. 3.1 NMOS Series Switch
    2. 3.2 NMOS/PMOS Parallel Switch
    3. 3.3 NMOS Series Switch with the Charge Pump
  5. 4Key Concerns in Digital-Switch Applications
    1. 4.1  Power and Control Voltage Requirements
    2. 4.2  Rail-to-Rail Operation
    3. 4.3  Undershoot
    4. 4.4  ron
    5. 4.5  Cio(off)
    6. 4.6  Cio(on)
    7. 4.7  Ci (Control Input Capacitance)
    8. 4.8  Leakage Current
    9. 4.9  Enable and Disable Delays and Propagation Delay
    10. 4.10 Partial Power Down
    11. 4.11 Voltage Translation
  6. 5Signal Switch Families
    1. 5.1 CBT-C Family
      1. 5.1.1 Characteristics of CBT-C Family
        1. 5.1.1.1 VOvs VI
        2. 5.1.1.2 ron vs VI
        3. 5.1.1.3 Undershoot Protection
      2. 5.1.2 Application of CBT-C Family
        1. 5.1.2.1 Bus Isolation
    2. 5.2 CBTLV Family
      1. 5.2.1 Characteristics of the CBTLV Family
    3. 5.3 CB3Q Family
      1. 5.3.1 Characteristics of the CB3Q Family
        1. 5.3.1.1 VOvs VI
        2. 5.3.1.2 ron vs VI
        3. 5.3.1.3 Operation at High Frequency
        4. 5.3.1.4 Output Skew
        5. 5.3.1.5 Frequency Response
        6. 5.3.1.6 Adjacent Channel Crosstalk
      2. 5.3.2 Application of the CB3Q Family
        1. 5.3.2.1 Multiplexer in USB Applications
    4. 5.4 CB3T Family
      1. 5.4.1 Characteristics of the CB3T Family
        1. 5.4.1.1 VO vs VI
        2. 5.4.1.2 ron vs VI
        3. 5.4.1.3 Operation at High Frequency
      2. 5.4.2 Application of the CB3T Family
        1. 5.4.2.1 Voltage Translation for an External Monitor Terminal in a Notebook PC
  7. 6Applications
    1. 6.1 Multiplexing USB Peripherals
    2. 6.2 Multiplexing Ethernet
    3. 6.3 Notebook Docking Station
  8. 7Conclusion
  9. 8References
  10. 9Revision History
  11.   A Test Measurement Circuits
    1.     A.1 Measurement Setup for ron
    2.     A.2 Measurement Setup for VO vs VI Characteristics
    3.     A.3 Voltage-Time Waveform Measurement (Switch On)
    4.     A.4 Voltage-Time Waveform Measurement (Switch Off)
    5.     A.5 Output-Skew Measurement
    6.     A.6 Simulation Setup for Undershoot Measurement
    7.     A.7 Laboratory Setup for Attenuation Measurement
    8.     A.8 Laboratory Setup for Off Isolation Measurement
    9.     A.9 Laboratory Setup for Crosstalk Measurement

5.2 CBTLV Family

The switches in the CBTLV (Low-Voltage Cross Bar Technology) family were the first general-purpose FET bus switches designed for 3.3 V systems. The devices in this family provide rail-to-rail switching and a low ron (5 Ω) and low CI/O (4.5 pF). CBTLV switches consist of a simple NMOS transistor in parallel with a PMOS transistor. When the switch is open, it provides tri-state isolation for its bus line. When the switch is closed, it imposes near-zero propagation delay on the line. Figure 5-6 shows a simplified schematic of a CBTLV device.

GUID-B0BF0EEC-CB9F-4FA9-ABA2-15947EBF406D-low.gif Figure 5-6 Simplified Schematic of a CBTLV Device