SLVSCE8C January   2015  – September 2018 TPS7B7701-Q1 , TPS7B7702-Q1

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Application Diagram
  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 Electrical Characteristics
    6. 6.6 Switching Characteristics
    7. 6.7 Typical Characteristics
  7. 7 Detailed Description
    1. 7.1 Overview
    2. 7.2 Functional Block Diagram
    3. 7.3 Feature Description
      1. 7.3.1  Fault Detection and Protection
      2. 7.3.2  Short-Circuit and Overcurrent Protection
      3. 7.3.3  Short-to-Battery and Reverse Current Detection
      4. 7.3.4  Thermal Shutdown
      5. 7.3.5  Integrated Reverse-Polarity Protection
      6. 7.3.6  Integrated Inductive Clamp
      7. 7.3.7  Undervoltage Lockout
      8. 7.3.8  Enable (EN, EN1, and EN2)
      9. 7.3.9  Internal Voltage Regulator (VCC)
      10. 7.3.10 Current Sense Multiplexing
      11. 7.3.11 Adjustable Output Voltage (FB, FB1, and FB2)
    4. 7.4 Device Functional Modes
      1. 7.4.1 Operation With IN < 4.5 V
      2. 7.4.2 Operation With EN Control
  8. 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. 8.2.2.1 Input Capacitor
        2. 8.2.2.2 Output Capacitor
        3. 8.2.2.3 Current Sense Resistor Selection
        4. 8.2.2.4 Current-Limit Resistor Selection
      3. 8.2.3 Application Curves
  9. 9 Power Supply Recommendations
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Documentation Support
      1. 11.1.1 Related Documentation
    2. 11.2 Related Links
    3. 11.3 Receiving Notification of Documentation Updates
    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

7.3.10 Current Sense Multiplexing

The two, independent current sense pins (one for each channel) provide flexibility in the system design. When the ADC resource is limited, the device allows the multiplexing of the current sense pins by only using one current sense pin and one ADC to monitor all the antenna outputs.

The SENSE_SEL pin (TPS7B7702-Q1 only) selects the channels to monitor the current. The SENSE_EN pin enables and disables the SENSE pin, allowing multiplexing between chips. Therefore, only one ADC and one resistor is needed for current-sense diagnostics of multiple outputs. When the SENSE1 pin is connected to an ADC, the current flow through both channels can be sensed by changing the electrical level at the SENSE_SEL pin.

Table 2 lists the selection logic for the current sense.

Table 2. SENSE_EN and SEN_SEL Logic Table

SENSE_EN SEN_SEL SENSE1 Status SENSE2 Status
LOW LOW CH1 current CH2 current
LOW HIGH CH2 current HIGH impedance
HIGH — HIGH impedance HIGH impedance

Figure 20 shows the application of four antenna channels sharing one ADC resource.

TPS7B7701-Q1 TPS7B7702-Q1 bd_current_mux_slvsce8.gifFigure 20. Current Multiplexing Application Block