SBOSA45D February   2022  – January 2025 TMP1826

PRODUCTION DATA  

  1.   1
  2. 1 Features
  3. 2 Applications
  4. 3 Description
  5. 4 Description (cont.)
  6. 5 Device Comparison
  7. 6 Pin Configuration and Functions
  8. 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 1-Wire® Interface Timing
    7. 7.7 EEPROM Characteristics
    8. 7.8 Timing Diagrams
    9. 7.9 Typical Characteristics
  9. 8 Detailed Description
    1. 8.1 Overview
    2. 8.2 Functional Block Diagram
    3. 8.3 Feature Description
      1. 8.3.1  Power Up
      2. 8.3.2  Power Mode Switch
      3. 8.3.3  Bus Pullup Resistor
      4. 8.3.4  Temperature Results
      5. 8.3.5  Temperature Offset
      6. 8.3.6  Temperature Alert
      7. 8.3.7  Standard Device Address
        1. 8.3.7.1 Unique 64-Bit Device Address and ID
      8. 8.3.8  Flexible Device Address
        1. 8.3.8.1 Non-Volatile Short Address
        2. 8.3.8.2 IO Hardware Address
        3. 8.3.8.3 Resistor Address
        4. 8.3.8.4 Combined IO and Resistor Address
      9. 8.3.9  CRC Generation
      10. 8.3.10 Functional Register Map
      11. 8.3.11 User Memory Map
      12. 8.3.12 Bit Communication
        1. 8.3.12.1 Host Write, Device Read
        2. 8.3.12.2 Host Read, Device Write
      13. 8.3.13 Bus Speed
      14. 8.3.14 NIST Traceability
    4. 8.4 Device Functional Modes
      1. 8.4.1 Conversion Modes
        1. 8.4.1.1 Basic One-Shot Conversion Mode
        2. 8.4.1.2 Auto Conversion Mode
        3. 8.4.1.3 Stacked Conversion Mode
        4. 8.4.1.4 Continuous Conversion Mode
      2. 8.4.2 Alert Function
        1. 8.4.2.1 Alert Mode
        2. 8.4.2.2 Comparator Mode
      3. 8.4.3 1-Wire® Interface Communication
        1. 8.4.3.1 Bus Reset Phase
        2. 8.4.3.2 Address Phase
          1. 8.4.3.2.1 READADDR (33h)
          2. 8.4.3.2.2 MATCHADDR (55h)
          3. 8.4.3.2.3 SEARCHADDR (F0h)
          4. 8.4.3.2.4 ALERTSEARCH (ECh)
          5. 8.4.3.2.5 SKIPADDR (CCh)
          6. 8.4.3.2.6 OVD SKIPADDR (3Ch)
          7. 8.4.3.2.7 OVD MATCHADDR (69h)
          8. 8.4.3.2.8 FLEXADDR (0Fh)
        3. 8.4.3.3 Function Phase
          1. 8.4.3.3.1  CONVERTTEMP (44h)
          2. 8.4.3.3.2  WRITE SCRATCHPAD-1 (4Eh)
          3. 8.4.3.3.3  READ SCRATCHPAD-1 (BEh)
          4. 8.4.3.3.4  COPY SCRATCHPAD-1 (48h)
          5. 8.4.3.3.5  WRITE SCRATCHPAD-2 (0Fh)
          6. 8.4.3.3.6  READ SCRATCHPAD-2 (AAh)
          7. 8.4.3.3.7  COPY SCRATCHPAD-2 (55h)
          8. 8.4.3.3.8  READ EEPROM (F0h)
          9. 8.4.3.3.9  GPIO WRITE (A5h)
          10. 8.4.3.3.10 GPIO READ (F5h)
      4. 8.4.4 NVM Operations
        1. 8.4.4.1 Programming User Data
        2. 8.4.4.2 Register and Memory Protection
          1. 8.4.4.2.1 Scratchpad-1 Register Protection
          2. 8.4.4.2.2 User Memory Protection
    5. 8.5 Programming
      1. 8.5.1 Single Device Temperature Conversion and Read
      2. 8.5.2 Multiple Device Temperature Conversion and Read
      3. 8.5.3 Register Scratchpad-1 Update and Commit
      4. 8.5.4 Single Device EEPROM Programming and Verify
      5. 8.5.5 Single Device EEPROM Page Lock Operation
      6. 8.5.6 Multiple Device IO Read
      7. 8.5.7 Multiple Device IO Write
    6. 8.6 Register Map
      1. 8.6.1  Temperature Result LSB Register (Scratchpad-1 offset = 00h) [reset = 00h]
      2. 8.6.2  Temperature Result MSB Register (Scratchpad-1 offset = 01h) [reset = 00h]
      3. 8.6.3  Status Register (Scratchpad-1 offset = 02h) [reset = 3Ch]
      4. 8.6.4  Device Configuration-1 Register (Scratchpad-1 offset = 04h) [reset = 70h]
      5. 8.6.5  Device Configuration-2 Register (Scratchpad-1 offset = 05h) [reset = 80h]
      6. 8.6.6  Short Address Register (Scratchpad-1 offset = 06h) [reset = 00h]
      7. 8.6.7  Temperature Alert Low LSB Register (Scratchpad-1 offset = 08h) [reset = 00h]
      8. 8.6.8  Temperature Alert Low MSB Register (Scratchpad-1 offset = 09h) [reset = 00h]
      9. 8.6.9  Temperature Alert High LSB Register (Scratchpad-1 offset = 0Ah) [reset = F0h]
      10. 8.6.10 Temperature Alert High MSB Register (Scratchpad-1 offset = 0Bh) [reset = 07h]
      11. 8.6.11 Temperature Offset LSB Register (Scratchpad-1 offset = 0Ch) [reset = 00h]
      12. 8.6.12 Temperature Offset MSB Register (Scratchpad-1 offset = 0Dh) [reset = 00h]
      13. 8.6.13 IO Read Register [reset = F0h]
      14. 8.6.14 IO Configuration Register [reset = 00h]
  10. 9 Application and Implementation
    1. 9.1 Application Information
    2. 9.2 Typical Applications
      1. 9.2.1 Bus Powered Application
        1. 9.2.1.1 Design Requirements
        2. 9.2.1.2 Detailed Design Procedure
      2. 9.2.2 Supply Powered Application
        1. 9.2.2.1 Design Requirements
        2. 9.2.2.2 Detailed Design Procedure
      3. 9.2.3 UART Interface for Communication
        1. 9.2.3.1 Design Requirements
        2. 9.2.3.2 Detailed Design Procedure
    3. 9.3 Power Supply Recommendations
    4. 9.4 Layout
      1. 9.4.1 Layout Guidelines
      2. 9.4.2 Layout Example
  11. 10Device and Documentation Support
    1. 10.1 Documentation Support
      1. 10.1.1 Related Documentation
    2. 10.2 Receiving Notification of Documentation Updates
    3. 10.3 Support Resources
    4. 10.4 Trademarks
    5. 10.5 Electrostatic Discharge Caution
    6. 10.6 Glossary
  12. 11Revision History
  13. 12Mechanical, Packaging, and Orderable Information

Package Options

Mechanical Data (Package|Pins)
Thermal pad, mechanical data (Package|Pins)
Orderable Information
8.4.3.2.3 SEARCHADDR (F0h)

The command is used by the host to identify the 64-bit address of each of the devices on the bus after the system is powered up (see Figure 8-21). Additionally, this command can be run by the host to discover any new devices that can be added to the system later. When there is a single device bus, the host can skip the command and instead use the SKIPADDR or OVD_SKIPADDR commands to access the device.

As shown in right side flow of Figure 8-21, when the fast arbitration mode is enabled by setting ARB_MODE bits as '11b' in the device configuration-2 register, the devices check the bus for the transmitted bit. If the device reads a bit value other than what was transmitted, the device no longer responds to the command until the next bus reset. A device that wins the bus continues until the 64th bit, sets the ARB_DONE bit in the status register to '1b' and stops responding to the next SEARCHADDR command. The arbitration function allows the host a fast discovery of the devices without having to go through the complicated, memory intensive and longer discovery method using traditional SEARCHADDR command. At the same time, if the host has an issue on the bus, then the host can simply perform a broadcast write to disable and enable the arbitration mode to restart the fast arbitration mode.

The device also features an optimized arbitration mode which is enabled by setting ARB_MODE bits as '10b'. The devices check the transmitted bit, and if the devices detect a logic '0' when the devices send a logic '1', the devices do not participate in the SEARCHADDR command until the next SEARCHADDR command is sent. The device that is able to send all 64 bits successfully, wins the bus and sets the ARB_DONE bit in the status register to '1b' and stops responding to next SEARCHADDR command. As a result of the optimized arbitration mode, the host does not have to manage the complex memory structure to identify devices on the bus and can still use the legacy software search algorithm.

The host must top searching for devices when the host receives "FFFFFFFFh". The host must disable the arbitration mode bits to clear the ARB_DONE status and enable only when the host wants to search for new devices added to the existing bus.

TMP1826 Address Search Algorithm Flowchart Figure 8-21 Address Search Algorithm Flowchart