SBOSAJ3 June   2024 TLV9104-Q1

PRODMIX  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Pin Configuration and Functions
  6. 5 Specifications
    1. 5.1 Absolute Maximum Ratings
    2. 5.2 ESD Ratings
    3. 5.3 Recommended Operating Conditions
    4. 5.4 Thermal Information for Quad Channel
    5. 5.5 Electrical Characteristics
    6. 5.6 Typical Characteristics
  7. 6 Detailed Description
    1. 6.1 Overview
    2. 6.2 Functional Block Diagram
    3. 6.3 Feature Description
      1. 6.3.1 EMI Rejection
      2. 6.3.2 Phase Reversal Protection
      3. 6.3.3 Thermal Protection
      4. 6.3.4 Capacitive Load and Stability
      5. 6.3.5 Common-Mode Voltage Range
      6. 6.3.6 Electrical Overstress
      7. 6.3.7 Overload Recovery
      8. 6.3.8 Typical Specifications and Distributions
    4. 6.4 Device Functional Modes
  8. 7 Application and Implementation
    1. 7.1 Application Information
    2. 7.2 Typical Applications
      1. 7.2.1 Low-Side Current Measurement
        1. 7.2.1.1 Design Requirements
        2. 7.2.1.2 Detailed Design Procedure
        3. 7.2.1.3 Application Curve
    3. 7.3 Power Supply Recommendations
    4. 7.4 Layout
      1. 7.4.1 Layout Guidelines
      2. 7.4.2 Layout Example
  9. 8 Device and Documentation Support
    1. 8.1 Device Support
      1. 8.1.1 Development Support
        1. 8.1.1.1 TINA-TI (Free Software Download)
    2. 8.2 Documentation Support
      1. 8.2.1 Related Documentation
    3. 8.3 Receiving Notification of Documentation Updates
    4. 8.4 Support Resources
    5. 8.5 Trademarks
    6. 8.6 Electrostatic Discharge Caution
    7. 8.7 Glossary
  10. 9 Revision History
  11. 10Mechanical, Packaging, and Orderable Information

7.2.1.2 Detailed Design Procedure

Use Equation 1 to calculate the transfer function of the circuit in Figure 7-1.

Equation 1. V O U T   = I L O A D ×   R S H U N T × G a i n

The load current (ILOAD) produces a voltage drop across the shunt resistor (RSHUNT). The load current is set from 0A to 1A. To keep the shunt voltage below 100mV at maximum load current, use Equation 2 to calculate the largest shunt resistor allowed.

Equation 2. R S H U N T   = V S H U N T _ M A X   I L O A D _ M A X   =   100   m V 1   A   =   100   m Ω

Using Equation 2, RSHUNT is calculated to be 100mΩ. The voltage drop produced by ILOAD and RSHUNT is amplified by the TLV910x-Q1 to produce an output voltage of 0V to 4.9V. Use Equation 3 to calculate the gain required for the TLV910x-Q1 to produce the necessary output voltage is calculated using.

Equation 3. G a i n   = ( V O U T _ M A X   –   V O U T _ M I N ) ( V I N _ M A X   –   V I N _ M I N )

Equation 3 calculates the required gain as 49V/V, which is set with resistors RF and RG. Equation 4 is used to size the resistors, RF and RG, to set the gain of the TLV910x-Q1 to 49V/V.

Equation 4. G a i n   =   1   +   ( R F ) ( R G )

With RF as 360kΩ, Equation 4 calculates RG as 7.5kΩ. This example has the RF and RG as 360kΩ and 7.5kΩ because these values are the standard resistor values that create a 49:1 ratio. Other resistors that create a 49:1 ratio can also be used. Figure 7-2 shows the measured transfer function of the circuit shown in Figure 7-1.