SLVUBX1 December   2020 TPS63810

 

  1.   Trademarks
  2. 1Introduction
  3. 2Quick Start
    1. 2.1 Step 1: Software Installation
    2. 2.2 Step 2: Firmware Completition and Flashing
    3. 2.3 Step 3: Hardware Setup
    4. 2.4 Step 4: GUI
  4. 3System Overview
  5. 4Hardware Overview
    1. 4.1 Buck-Boost Converter
    2. 4.2 Thermoelectric Cooler (TEC)
    3. 4.3 LaunchPad
    4. 4.4 Voltage Reference
    5. 4.5 Temperature Sensor
  6. 5Firmware Overview
  7. 6Graphical User Interface (GUI)
  8. 7Setup Details
  9. 8Bill of Materials, PCB Layout, and Schematic
    1. 8.1 Bill of Materials
    2. 8.2 PCB Layout
    3. 8.3 Schematic

Temperature Sensor

Different types of temperature sensors can be used with the BOOSTXL-TECDRV BoosterPack. The sensors can be connected to the screw terminal on the BoosterPack to interface them to the I2C interface or the ADC of the LaunchPad’s MCU.

By default, the provided firmware is intended to be used with the TMP117 temperature sensor. The TMP117 is a high-precision digital temperature sensor. The TMP117 provides a 16-bit temperature result with a resolution of 0.0078°C and an accuracy of up to ±0.1°C across the temperature range of -20°C to 50°C with no calibration. The TMP117 has an I2C-compatible interface. The low power consumption of the TMP117 minimizes the impact of self-heating on measurement accuracy. The TMP117 operates from 1.8 V to 5.5 V and typically consumes 3.5 μA.

An nalog temperature sensor can also be used. The analog sensor is interfaced to the 16-bit ADC integrated into the MSP-EXP432P401R LaunchPad. The provided firmware is already prepared for reading the analog input. The user only has to provide the conversion equation to translate the ADC value into the temperature. Typically, three types of analog temperature sensors are used:

  1. Linear analog temperature sensors, which provides a voltage output that changes linearly with the temperature. An example is the LMT70, an ultra-small, high-precision, low-power CMOS analog temperature sensor with NTC output slope of -5.19 mV/°C and accuracy of ±0.05°C.
  2. Positive temperature coefficient (PTC) thermistor, which is a resistor whose resistance increases as temperature rises. An example is the TMP61, a ±1% 10-kΩ silicon-based thermistor offering linearity and consistent sensitivity across temperature.
  3. Negative temperature coefficient (NTC) thermistor, which is a resistor whose resistance decreases as temperature rises.

Note that PTC and NTC thermistors require a biasing resistor to form a resistive voltage divider whose output voltage depends on the temperature. The BOOSTXL-TECDRV BoosterPack has already included place for this resistor on board. It should also be noted that PTC thermistors have benefits over NTC thermistors such as no extra linearization circuitry, minimized calibration, less resistance tolerance variation, larger sensitivity at high temperatures, and simplified conversion methods to save time and memory in the processor. Use the thermistor design tool to view resistance tables and begin your design with example temperature conversion methods and code.