When the Mode bit is set to 0 in the Configuration register, the device operates in continuous conversion mode. Figure 8-4 shows that the device continuously performs temperature conversions in this mode. The TMP126 does not wait until the end of the conversion period to update the temperature, instead the temperature result register is updated at the end of the temperature conversion. After a completed active conversion, the Data_Ready flag bit is set to 1. The user can read the interrupt/status register or the temperature result register to clear the Data_Ready flag. Therefore, the Data_Ready_Flag can be used to determine when the conversion completes so that an external controller can synchronize reading the result register with conversion result updates. The user can set the Data_Ready_Flag_En bit in the configuration register to monitor the state of the Data_Ready_Flag on the ALERT pin.

Every conversion period consists of an active temperature conversion followed by a standby period. During standby the TMP126 will de-activate all measurement circuitry to conserve power but will remain available for any SPI communication. The device typically consumes 75 µA during the temperature conversion and only 1 µA during the low-power standby period. The duration of the temperature conversion will remain fixed, but the conversion period can be configured using the Conv_Period[2:0] bit field in the Configuration register, allowing the average current consumption of the device to be optimized based on the application requirements. Changing the conversion period also affects the temperature result update rate due to the temperature result register being updated at the end of every temperature conversion.

Use Equation 1 to calculate the average current consumption of the device in continuous conversion mode.

Equation 1.

Figure 8-4 Conversion Period Timing Diagram