SLOS954A July   2018  – December 2018 INA253


  1. Features
  2. Applications
  3. Description
    1.     Typical Application
  4. Revision History
  5. Device Comparison Table
  6. Pin Configuration and Functions
    1.     Pin Functions
  7. Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information
    5. 7.5 Electrical Characteristics
    6. 7.6 Typical Characteristics
  8. Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Integrated Shunt Resistor
      2. 8.3.2 Short-Circuit Duration
      3. 8.3.3 Temperature Stability
      4. 8.3.4 Enhanced PWM Rejection Operation
      5. 8.3.5 Input Signal Bandwidth
    4. 8.4 Device Functional Modes
      1. 8.4.1 Adjusting the Output Midpoint With the Reference Pins
      2. 8.4.2 Reference Pin Connections for Unidirectional Current Measurements
      3. 8.4.3 Ground Referenced Output
      4. 8.4.4 Reference Pin Connections for Bidirectional Current Measurements
        1. Output Set to External Reference Voltage
      5. 8.4.5 Output Set to Mid-Supply Voltage
      6. 8.4.6 Output Set to Mid-External Reference
      7. 8.4.7 Output Set Using Resistor Divide
  9. Application and Implementation
    1. 9.1 Application Information
      1. 9.1.1 Input Filtering
    2. 9.2 Typical Applications
      1. 9.2.1 High-Side, High-Drive, Solenoid Current-Sense Application
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      2. 9.2.2 Speaker Enhancements and Diagnostics Using Current Sense Amplifier
        1. Design Requirements
        2. Detailed Design Procedure
        3. Application Curve
      3. 9.2.3 Current Sensing for Remote I/Os in PLC
        1. Design Requirements
        2. Application Curve
  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 Development Support
    2. 12.2 Related Documentation
    3. 12.3 Receiving Notification of Documentation Updates
    4. 12.4 Community Resources
    5. 12.5 Trademarks
    6. 12.6 Electrostatic Discharge Caution
    7. 12.7 Glossary
  13. 13Mechanical, Packaging, and Orderable Information

Package Options

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

Input Filtering


Input filters are not required for accurate measurements using the INA253. For most accurate results, do not use filters at the IN+ and IN– inputs. However, If filter components are used on the input of the amplifier, follow the guidelines in this section to minimize effects on performance.

Based strictly on user design requirements, external filtering of the current signal may be desired. The initial location that can be considered for the filter is at the output of the current amplifier. Although placing the filter at the output satisfies the filtering requirements, this location changes the low output impedance measured by any circuitry connected to the output voltage pin. The other location for filter placement is at the current amplifier input pins. This location also satisfies the filtering requirement, but carefully select the components to minimize the impact on device performance. Figure 39 shows a filter placed at the inputs pins.

INA253 ina253-filter-at-input-pins.gifFigure 39. Filter at Input Pins

External series resistance provides a source of additional measurement error. Therefore, keep the value of these series resistors to 10-Ω or less in order to reduce loss of accuracy. The internal bias network shown in Figure 39 creates a mismatch in input bias currents when a differential voltage is applied between the input pins (see Figure 40). If additional external series filter resistors are added to the circuit, a mismatch is created in the voltage drop across the filter resistors. This voltage is a differential error voltage in the shunt resistor voltage. In addition to the absolute resistor value, mismatch resulting from resistor tolerance can significantly impact the error because this value is calculated based on the actual measured resistance.

INA253 D029_ibpmvdiff_SBOS662.gifFigure 40. Input Bias Current vs Differential Input Voltage

Calculate the measurement error expected from the additional external filter resistors using Equation 1.

Equation 1. INA253 q_gainerror_percent_bas437.gif


  • Gain Error Factor is calculated using Equation 2.
Equation 2. INA253 input-filter-eq.gif


  • RS is the external filter resistance value

Calculate the gain error factor, shown in Equation 2, in order to determine the gain error introduced by the additional external series resistance. Equation 1 calculates the deviation of the shunt voltage resulting from the attenuation and imbalance created by the added external filter resistance. Table 1 provides the gain error factor and gain error for several resistor values.

Table 1. Gain Error Factor and Gain Error for External Input Resistors

5 0.998 0.17
10 0.997 0.33
100 0.968 3.23