SNOU204 October   2024

 

  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
  8. 2Hardware
    1. 2.1 Overview
    2. 2.2 Perforations and Connectivity
    3. 2.3 Status LEDs (D3, D5, D6) and Subregulator
    4. 2.4 Programming Header
    5. 2.5 BSL Button
    6. 2.6 Remote BJT - Q1
    7. 2.7 Address Jumpers
    8. 2.8 Current Measurement - SEL Measurement
  9. 3Software
    1. 3.1 Software Installation
      1. 3.1.1 Live Software on dev.ti.com
      2. 3.1.2 Download from dev.ti.com
    2. 3.2 Home Tab
    3. 3.3 Data Capture Tab
    4. 3.4 Registers Tab
  10. 4Hardware Design Files
    1. 4.1 Schematic
    2. 4.2 PCB Layout
    3. 4.3 Bill of Materials
  11. 5Additional Information
    1. 5.1 Trademarks

2.8 Current Measurement - SEL Measurement

This EVM provides two approaches in measuring the total quiescent current of the TMP9R01 device. Within this section of the EVM, there is a jumper and three test points: TP1, TP2, and GND.

Option 1: Measure the current through the resistor with known voltage measurements of TP1 and TP2. The jumper is in parallel with a resistor. To take advantage of this option, users need to remove the jumper and repopulate the resistor R21 with a value of your choice.

Option 2: Using a SMU to supply voltage and measure current through TP2 and GND. To take advantage of this option, remove R21 resistor, switch off the USB power through the Subregulator switch and supply TP1 and TP2 with the same voltage within the range of 1.7V to 3.6V.

When measuring current through this device, the following images show what to expect for the current output. There are different current ranges for what mode the device is in. Shutdown mode consumes the least amount of power vs active conversion mode consumes the most amount of power.

TYP (µA)MAX (µA)
IqActive conversion, local sensor240375
Active conversion, remote sensor400600
Standby mode (between conversions)1535
Shutdown mode, serial bus inactive38
Shutdown mode, serial bus active, fs = 400kHz90
Shutdown mode, serial bus active, fs = 2.17MHz350
TMP9R01EVM Expected Total Quiescent Current with Communication
A. VDD is at 5.5V.
Figure 2-2 Expected Total Quiescent Current with Communication
TMP9R01EVM Expected Total Quiescent Current without Communication
A. VDD is at 3.3V.
Figure 2-3 Expected Total Quiescent Current without Communication