SLOS877C October   2014  – April 2021 TMP451-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 Timing Characteristics for Figure 1-1
    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 Temperature Measurement Data
        1. 7.3.1.1 Standard Binary to Decimal Temperature Data Calculation Example
        2. 7.3.1.2 Standard Decimal to Binary Temperature Data Calculation Example
      2. 7.3.2 Series Resistance Cancellation
      3. 7.3.3 Differential Input Capacitance
      4. 7.3.4 Filtering
      5. 7.3.5 Sensor Fault
      6. 7.3.6 ALERT and THERM Functions
    4. 7.4 Device Functional Modes
      1. 7.4.1 Shutdown Mode (SD)
    5. 7.5 Programming
      1. 7.5.1 Serial Interface
        1. 7.5.1.1 Bus Overview
        2. 7.5.1.2 Bus Definitions
        3. 7.5.1.3 Serial Bus Address
        4. 7.5.1.4 Read and Write Operations
        5. 7.5.1.5 Timeout Function
        6. 7.5.1.6 High-Speed Mode
    6. 7.6 Register Map
      1. 7.6.1 Register Information
        1. 7.6.1.1  Pointer Register
        2. 7.6.1.2  Temperature Registers
        3. 7.6.1.3  Status Register
        4. 7.6.1.4  Configuration Register
        5. 7.6.1.5  Conversion Rate Register
        6. 7.6.1.6  One-Shot Start Register
        7. 7.6.1.7  η-Factor Correction Register
        8. 7.6.1.8  Offset Register
        9. 7.6.1.9  General Call Reset
        10. 7.6.1.10 Identification Register
  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 Curves
  9. 9 Power Supply Recommendations
  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

7.6.1.3 Status Register

The status register reports the state of the temperature ADC, the temperature limit comparators, and the connection to the remote sensor. Table 7-5 lists the status register bits. The status register is read-only, and is read by accessing pointer address 02h.

Table 7-5 Status Register Format
STATUS REGISTER (READ = 02h, WRITE = N/A)
BIT NUMBER BIT NAME FUNCTION
7 BUSY = 1 when the ADC is converting
6 LHIGH(1) = 1 when the local high temperature limit is tripped
5 LLOW(1) = 1 when the local low temperature limit is tripped
4 RHIGH(1) = 1 when the remote high temperature limit is tripped
3 RLOW(1) = 1 when the remote low temperature limit is tripped
2 OPEN(1) = 1 when the remote sensor is an open circuit
1 RTHRM = 1 when the remote THERM limit is tripped
0 LTHRM = 1 when the local THERM limit is tripped
(1) These flags stay high until the status register is read or they are reset by a POR when pin 6 is configured as ALERT. Only bit 2 (OPEN) stays high until the status register is read or it is reset by a POR when pin 6 is configured as THERM2.

The BUSY bit = 1 if the ADC is making a conversion. This bit is set to 0 if the ADC is not converting.

The LHIGH and LLOW bits indicate a local sensor overtemperature or undertemperature event, respectively. The RHIGH and RLOW bits indicate a remote sensor overtemperature or undertemperature event, respectively. The OPEN bit indicates an open circuit condition on the remote sensor. When pin 6 is configured as the ALERT output, the five flags are NORed together. If any of the five flags are high, the ALERT interrupt latch is set and the ALERT output goes low. Reading the status register clears the five flags, provided that the condition that caused the setting of the flags is not present anymore (that is, the value of the corresponding result register is within the limits, or the remote sensor is connected properly and functional). The ALERT interrupt latch (and the ALERT pin correspondingly) is not reset by reading the status register. The reset is done by the master reading the temperature sensor device address to service the interrupt, and only if the flags have been reset and the condition that caused them to be set is not present.

The RTHRM and LTHRM flags are set when the corresponding temperature exceeds the programmed THERM limit. They are reset automatically when the temperature returns to within the limits. The THERM output goes low in the case of overtemperature on either the local or the remote channel, and goes high as soon as the measurements are within the limits again. The THERM hysteresis register (21h) allows hysteresis to be added so that the flag resets and the output goes high when the temperature returns to or goes below the limit value minus the hysteresis value.

When pin 6 is configured as THERM2, only the high limits matter. The LHIGH and RHIGH flags are set if the respective temperatures exceed the limit values, and the pin goes low to indicate the event. The LLOW and RLOW flags have no effect on THERM2, and the output behaves the same way when configured as THERM.