SNOU220B July   2025  – November 2025

 

  1.   1
  2.   Description
  3.   Get Started
  4.   Features
  5.   Applications
  6.   6
  7. 1Evaluation Module Overview
    1. 1.1 Introduction
    2. 1.2 Kit Contents
    3. 1.3 Specification
    4. 1.4 Device Information
    5. 1.5 General Texas Instruments High Voltage Evaluation (TI HV EVM) User Safety Guidelines
  8. 2Hardware
    1. 2.1 Overview
    2. 2.2 High Voltage Connection Setup Guide
      1. 2.2.1 Detaching the Sensor
      2. 2.2.2 Attaching Sensor Section to High Voltage Heat Source
    3. 2.3 Perforations
    4. 2.4 Status LEDs and Subregulator
    5. 2.5 Programming Header
    6. 2.6 Pushbutton Switch
    7. 2.7 RC Filter
  9. 3Software
    1. 3.1 Software Download
      1. 3.1.1 Online Software
      2. 3.1.2 Offline Software
    2. 3.2 Home Tab
    3. 3.3 Data Capture Tab
    4. 3.4 Collateral Tab
  10. 4Hardware Design Files
    1. 4.1 ISOTMP35REVM Schematic
    2. 4.2 PCB Layout
    3. 4.3 Bill of Materials
  11. 5Additional Information
    1. 5.1 Trademarks
  12. 6Revision History

2.7 RC Filter

On the sensor breakout board, R15 and C20 can be used for an optional RC circuit to filter the voltage output of the ISOTMP35R. R15 is already installed on the board, but is a 0Ω jumper so acts as a short. C20 is not installed by default. The user can desolder R15, solder on a different resistor in the place of R15, and solder on a capacitor for C20 to create an RC filter.

The user must be aware to not use a capacitor value greater than 120nF for C20. The ISOTMP35R has a maximum capacitive load of 220nF, however C17 on the controller portion of the EVM is a 100nF cap that is loaded onto the output voltage line. C17 prevents the voltage from dropping on the microcontroller ADC input, so C17 must not be removed. The ADC pin of the MSP430F5528 has 15pF of capacitive loading as well, although this is considered negligent when working on the scale of hundreds of nF.

To maintain output stability, phase margin (PM) must not be allowed to drop below 65°. When choosing a resistor and capacitor for an RC filter, take care to refer to the ISOTMP35R data sheet to find resistor and capacitor values to keep the PM above 65°. C17, the 100nF capacitor placed near the ADC on the MCU side of the PCB, does count as part of the total capacitance for the PM calculation. For example if the user wants a filter with 200nF and 950Ω, the user must install a 100nF capacitor for C20.