SBOS879D July   2017  – October 2019 MCP6291 , MCP6292 , MCP6294

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Low-Side Motor Control
      2.      Small-Signal Overshoot vs Load Capacitance
  4. 4 Revision History
  5. 5 Device Comparison Table
  6. 6 Pin Configuration and Functions
    1.     Pin Functions: MCP6921
    2.     Pin Functions: MCP6292
    3.     Pin Functions: MCP6294
  7. 7 Specifications
    1. 7.1 Absolute Maximum Ratings
    2. 7.2 ESD Ratings
    3. 7.3 Recommended Operating Conditions
    4. 7.4 Thermal Information: MCP6291
    5. 7.5 Thermal Information: MCP6292
    6. 7.6 Thermal Information: MCP6294
    7. 7.7 Electrical Characteristics: VS (Total Supply Voltage) = (V+) – (V–) = 2.4 V to 5.5 V
    8. 7.8 Typical Characteristics
  8. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1 Rail-to-Rail Input
      2. 8.3.2 Rail-to-Rail Output
      3. 8.3.3 Overload Recovery
    4. 8.4 Device Functional Modes
  9. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Application
      1. 9.2.1 Design Requirements
      2. 9.2.2 Detailed Design Procedure
      3. 9.2.3 Application Curve
  10. 10Power Supply Recommendations
    1. 10.1 Input and ESD Protection
  11. 11Layout
    1. 11.1 Layout Guidelines
    2. 11.2 Layout Example
  12. 12Device and Documentation Support
    1. 12.1 Documentation Support
      1. 12.1.1 Related Documentation
    2. 12.2 Related Links
    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

9.2.2 Detailed Design Procedure

The transfer function of the circuit in Figure 33 is shown in Equation 1.

Equation 1. MCP6291 MCP6292 MCP6294 EQ_2_SBOS701.gif

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

Equation 2. MCP6291 MCP6292 MCP6294 EQ_3_SBOS701.gif

Using Equation 2, RSHUNT is 100 mΩ. The voltage drop produced by ILOAD and RSHUNT is amplified by the MCP629x to produce an output voltage of roughly 0 V to 4.95 V. The gain needed by the MCP629x to produce the necessary output voltage is calculated using Equation 3:

Equation 3. MCP6291 MCP6292 MCP6294 EQ_4_SBOS701.gif

Using Equation 3, the required gain is calculated to be 49.5 V/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 MCP629x to 49.5 V/V.

Equation 4. MCP6291 MCP6292 MCP6294 EQ_5_SBOS701.gif

Choosing RF as 165 kΩ and RG as 3.4 kΩ provides a combination that equals roughly 49.5 V/V. Figure 34 shows the measured transfer function of the circuit shown in Figure 33.