SBOS835C May   2017  – October 2019 TMP464

PRODUCTION DATA.  

  1. 1 Features
  2. 2 Applications
  3. 3 Description
    1.     Device Images
      1.      Typical Application 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 Recommended Operating Conditions
    4. 6.4 Thermal Information
    5. 6.5 Electrical Characteristics
    6. 6.6 Two-Wire 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 Temperature Measurement Data
      2. 7.3.2 Series Resistance Cancellation
      3. 7.3.3 Differential Input Capacitance
      4. 7.3.4 Sensor Fault
      5. 7.3.5 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
          1. 7.5.1.4.1 Single Register Reads
          2. 7.5.1.4.2 Block Register Reads
        5. 7.5.1.5 Timeout Function
        6. 7.5.1.6 High-Speed Mode
      2. 7.5.2 TMP464 Register Reset
      3. 7.5.3 Lock Register
    6. 7.6 Register Maps
      1. 7.6.1 Register Information
        1. 7.6.1.1  Pointer Register
        2. 7.6.1.2  Local and Remote Temperature Value Registers
        3. 7.6.1.3  Software Reset Register
        4. 7.6.1.4  THERM Status Register
        5. 7.6.1.5  THERM2 Status Register
        6. 7.6.1.6  Remote Channel Open Status Register
        7. 7.6.1.7  Configuration Register
        8. 7.6.1.8  η-Factor Correction Register
        9. 7.6.1.9  Remote Temperature Offset Register
        10. 7.6.1.10 THERM Hysteresis Register
        11. 7.6.1.11 Local and Remote THERM and THERM2 Limit Registers
        12. 7.6.1.12 Block Read - Auto Increment Pointer
        13. 7.6.1.13 Lock Register
        14. 7.6.1.14 Manufacturer and Device Identification Plus Revision Registers
  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
  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 Community 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

7.6.1.7 Configuration Register

The Configuration Register sets the conversion rate, starts one-shot conversion of all enabled channels, enables conversion the temperature channels, controls the shutdown mode and reports when a conversion is in process. The Configuration Register is set by writing to pointer address 30h, and is read from pointer address 30h. Table 8 summarizes the bits of the Configuration Register.

Table 8. Configuration Register Bit Descriptions

CONFIGURATION REGISTER (READ = 30h, WRITE = 30h, POR = 0x0F9C)
BIT NUMBER NAME FUNCTION POWER-ON-RESET VALUE
15:12 0 Reserved for future use; always reports 0 0000
11:8 REN4:REN1 1 = enable respective remote channel 4 through 1 conversions 1111
7 LEN 1 = enable local channel conversion 1
6 OS 1 = start one-shot conversion on enabled channels 0
5 SD 1 = enables device shutdown 0
4:2 CR2:CR0 Conversion rate control bits; control conversion rates for all enabled channels from 16 seconds to continuous conversion 111
1 BUSY 1 when the ADC is converting (read-only bit ignores writes) 0
0 Reserved — 0

The Remote Enable four through one (REN4:REN1, bits 11:8) bits enable conversions on the respective remote channels. The Local Enable (LEN, bit 7) bit enables conversions of the local temperature channel. If all LEN and REN are set to 1 (default), this enables the ADC to convert the local and all remote temperatures. If the LEN is set to 0, the local temperature conversion is skipped. Similarly if a REN is set to 0, that remote temperature conversion channel is skipped. The TMP464 device steps through each enabled channel in a round-robin fashion in the following order: LOC, REM1, REM2, REM4, LOC, REM1, and so on. All local and remote temperatures are converted by the internal ADC by default after power up. The configuration register LEN and REN bits can be configured to save power by reducing the total ADC conversion time for applications that do not require all of the four remote and local temperature information. Note writing all zeros to REN4:REN1 and LEN has the same effect as SD = 1 and OS = 0.

The shutdown bit (SD, bit 5) enables or disables the temperature-measurement circuitry. If SD = 0 (default), the TMP464 device converts continuously at the rate set in the conversion rate register. When SD is set to 1, the TMP464 device immediately stops the conversion in progress and instantly enters shutdown mode. When SD is set to 0 again, the TMP464 device resumes continuous conversions starting with the local temperature.

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

After the TMP464 device is in shutdown mode, writing a 1 to the one-shot (OS, bit 6) bit starts a single ADC conversion of all the enabled temperature channels. This write operation starts one conversion and comparison cycle on either the four remote and one local sensor or any combination of sensors, depending on the LEN and REN values in the Configuration Register (read address 30h). The TMP464 device returns to shutdown mode when the cycle is complete. Table 9 details the interaction of the SD, OS, LEN, and REN bits.

Table 9. Conversion Modes

WRITE READ FUNCTION
REN[8:1], LEN OS SD REN[8:1], LEN OS SD
All 0 — — All 0 0 1 Shutdown
At least 1 enabled — 0 Written value 0 0 Continuous conversion
At least 1 enabled 0 1 Written value 0 1 Shutdown
At least 1 enabled 1 1 Written value 1 1 One-shot conversion

The conversion rate bits control the rate that the conversions occur (CR2:CR0, bits 4:2). The value of CR2:CR0 bits controls the idle time between conversions but not the conversion time itself, which allows the TMP464 device power dissipation to be balanced with the update rate of the temperature register. Table 10 describes the mapping for CR2:CR0 to the conversion rate or temperature register update rate.

Table 10. Conversion Rate

CR2:CR0 DECIMAL VALUE FREQUENCY (Hz) TIME (s)
000 0 0.0625 16
001 1 0.125 8
010 2 0.25 4
011 3 0.5 2
100 4 1 1
101 5 2 0.5
110 6 4 0.25
111 7 Continuous conversion; depends on number of enabled channels; see Table 11 (default).

Table 11. Continuous Conversion Times

NUMBER OF REMOTE CHANNELS ENABLED CONVERSION TIME (ms)
LOCAL DISABLED LOCAL ENABLED
0 0 15.5
1 15.8 31.3
2 31.6 47.1
3 47.4 62.9
4 63.2 78.7

The remaining bits of the configuration register are reserved and must always be set to 0. The POR value for this register is 0x0F9C.