SBOSA37A November   2020  – March 2023 ALM2403-Q1

PRODUCTION DATA  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
  4. 4 Revision History
  5. 5 Pin Configuration and 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 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 Overtemperature and Shutdown Pin (OTF/SH_DN)
      2. 7.3.2 Thermal Shutdown
      3. 7.3.3 Current-Limit and Short-Circuit Protection
      4. 7.3.4 Input Common-Mode Range
      5. 7.3.5 Reverse Body Diodes in Output-Stage Transistors
      6. 7.3.6 EMI Filtering
    4. 7.4 Device Functional Modes
      1. 7.4.1 Open-Loop and Closed-Loop Operation
      2. 7.4.2 Shutdown
  8. 8 Application and Implementation
    1. 8.1 Application Information
      1. 8.1.1 Capacitive Load and Stability
    2. 8.2 Typical Application
      1. 8.2.1 Design Requirements
      2. 8.2.2 Detailed Design Procedure
        1. 8.2.2.1 Resolver Excitation Amplifier Combined With MFB 2nd-Order, Low-Pass Filter
          1. 8.2.2.1.1 Filter Design
          2. 8.2.2.1.2 Short-to-Battery Protection
        2. 8.2.2.2 Power Dissipation and Thermal Reliability
          1. 8.2.2.2.1 Improving Package Thermal Performance
      3. 8.2.3 Application Curves
    3. 8.3 Power Supply Recommendations
    4. 8.4 Layout
      1. 8.4.1 Layout Guidelines
      2. 8.4.2 Layout Example
  9. 9 Device and Documentation Support
    1. 9.1 Documentation Support
      1. 9.1.1 Related Documentation
    2. 9.2 Receiving Notification of Documentation Updates
    3. 9.3 Support Resources
    4. 9.4 Trademarks
    5. 9.5 Electrostatic Discharge Caution
    6. 9.6 Glossary
  10. 10Mechanical, Packaging, and Orderable Information

Package Options

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

8.2.2.2 Power Dissipation and Thermal Reliability

Power dissipation is critical to many industrial and automotive applications. Resolvers are typically chosen over other position feedback techniques because of reliability and accuracy in harsh conditions and high temperatures.

The ALM2403-Q1 is capable of high output current with power-supply voltages up to 24 V. Internal power dissipation increases when operating at high supply voltages. The power dissipated in the op amp (POPA) is calculated using Equation 4:

Equation 4. POPA= VS- VOUT×IOUT= VS- VOUT×VOUTRL

To calculate the worst-case power dissipation in the op amp, the ac and dc cases must be considered separately.

In the case of constant output current (dc) to a resistive load, the maximum power dissipation in the op amp occurs when the output voltage is half the positive supply voltage. This calculation assumes that the op amp is sourcing current from the positive supply to a grounded load. If the op amp sinks current from a grounded load, modify Equation 5 to include the negative supply voltage instead of the positive.

Equation 5. P O P A M A X ⎽ D C =   P O P A V S 2 =   V S 2 4   ×   R L

The ac maximum of average power dissipation in the op amp for a sinusoidal output current (ac) to a resistive load occurs when the peak output voltage is 2/π times the supply voltage, given symmetrical supply voltages, as shown in Equation 6:

Equation 6. P O P A P E A K ⎽ A C =   P O P A 2   ×   V S π =   2   ×   V S 2 π 2   ×   R L

After the total power dissipation is determined, the junction temperature at the worst expected ambient temperature case must be determined by using Equation 7:

Equation 7. T J M A X = P O P A × R θ J A +   T A M A X