SLIS136C September   2011  – September 2019 TPL0501-100

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Simplified Schematic
  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 Thermal Information
    4. 6.4 Electrical Characteristics: Analog Specifications
    5. 6.5 Electrical Characteristics: Operating Specifications
    6. 6.6 Timing Requirements
    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 Single-Channel, 256-Position Resolution
    4. 7.4 Device Functional Modes
      1. 7.4.1 Voltage Divider Mode
      2. 7.4.2 Rheostat Mode
    5. 7.5 Programming
      1. 7.5.1 SPI Digital Interface
        1. Table 1. Register Map - Default Value 0x80
      2. 7.5.2 Ideal Resistance Values
  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
      3. 8.2.3 Application Curve
  9. 9 Power Supply Recommendations
    1. 9.1 Power Sequence
    2. 9.2 Wiper Position Upon Power Up
  10. 10Layout
    1. 10.1 Layout Guidelines
    2. 10.2 Layout Example
  11. 11Device and Documentation Support
    1. 11.1 Receiving Notification of Documentation Updates
    2. 11.2 Support Resources
    3. 11.3 Trademarks
    4. 11.4 Electrostatic Discharge Caution
    5. 11.5 Glossary
  12. 12Mechanical, Packaging, and Orderable Information

Package Options

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

7.4.2 Rheostat Mode

The TPL0501 operates in rheostat mode when only two terminals are used as a variable resistor. The variable resistance can either be between terminal H and terminal W or between terminal L and terminal W. The unused terminal can be left floating or it can be tied to terminal W. The nominal resistance between terminal H and terminal L is 10 kΩ and has 256 tap points accessed by the wiper terminal. The 8-bit volatile register value is used to determine one of the 256 possible wiper positions.

To set the resistance between terminal H and terminal W in rheostat mode, the potentiometer can be configured in two possible ways (see Figure 13).

TPL0501-100 dfm_rheostat_m1_slis134.gifFigure 13. Equivalent Circuit for Rheostat Mode With Terminal H to Terminal W Resistance

The general equation for determining the digitally programmed output resistance between Terminal H and Terminal W is Equation 3:

Equation 3. TPL0501-100 eq3_slis134.gif

where

  • RTOT is the end-to-end resistance between terminal H and terminal L.
  • D is the decimal value of the wiper code

Similarly, to set the resistance between terminal L and terminal W, the potentiometer can be configured in two possible ways.

TPL0501-100 dfm_rheostat_m2_slis134.gifFigure 14. Equivalent Circuit for Rheostat Mode With Terminal L to Terminal W Resistance

The general equation for determining the digitally programmed output resistance between terminal L and terminal W is Equation 4:

Equation 4. TPL0501-100 eq4_slis134.gif

where

  • RTOT is the end-to-end resistance between terminal H and terminal L
  • D is the decimal value of the wiper code.