Test T5: Power Consumption of the Module

Test T5: Power Consumption of the Module

MSD P11207Test Plan1/5/11

Test T5: Power Consumption of the module

Objective

Engineering Specs Tested: ES7

This test will measure the current consumption of the module.

Equipment Required

2 laptop computers running Windows

2 copies of TI SmartRF Studio software

2 copies of TI SmartRF Flash Programmer

2 USB cables (Type A to Type B)

2 TI CC Debuggers

2 Mid-Range RF modules

1 External Power Supply

1 Oscilloscope

1 Oscilloscope Probe

Prototype board

Resistor 10Ω

Location

EE Lab

Procedure:

Figure 1: Measurement Setup

The current consumption varies rapidly and to estimate the maximal current consumption, the current is measured with an oscilloscope voltage probe over a 10Ω resistor in series with the power supply. The use of the resistor and oscilloscope allows measurement of the current consumption as a function of time, and is therefore necessary to calculate battery life time.

This method also gives a visual representation of the current consumption during active and sleep mode of the device.

Note: This measurement method may influence the result because of the voltage drop over the resistor and the stray (cable) resistance. Ideally the measurement setup should have been verified with a high precision amperemeter. However the accuracy will be defined by other factors and a higher accuracy here would not affect the final results. The results are also read manually from the oscilloscope, which will also influence on the accuracy.

Note: All the files needed during this procedure can be found on the Edge website of Project 11207, under MSD II/Test Plan/ Test Plan Files

  1. Place laptops 5 meters apart on a table, with a clear line of sight
  2. Configure the power supply to provide 3.3V with a minimum current of 500mA. Don’t turn it on yet.
  3. Create the circuit corresponding to the schematic in figure 1 and connectmodule A to the power supplyand the oscilloscope as indicated.
  4. Connect module A to laptop A using the CC Debugger (for data communication)
  5. Turn on the Power supply
  6. Connect module B to laptop B using the USB cable (for power supply)
  7. Connect also module B to laptop B via CC Debugger (for data communication)
  8. On both computers, run TI Smart RF Flash Programmer:
  9. In the System on Chip Window, select your device, which should have the Chip Type CC1111
  10. In the section Flash image, Select the file “Power_Test.hex”
  11. In the section actions, select “Erase, Program and Verify”
  12. Click on “Perform actions”
  13. Close Flash Programmer
  14. Repeat with the second module
  15. Power on laptop “A” (Transmitter), and run Texas Instruments SmartRF Studio 7 software.

Figure 2: Smart RF Studio First Window

  1. Select CC1111

Figure 3: Smart RF Studio TX Window

  1. In the new window, Select “Expert Mode”
  2. Select the Field “Packet TX” in the bottom of the window
  3. Open file configuration “Power_TX_Configuration.srfs” (File/Open Cfg)
  1. Power on laptop “B” (Receiver), and run also Texas Instruments Smart RF Studio.
  2. Select CC1111
  3. In the new window, Select “Expert Mode”
  4. Select the Field “Packet TX” in the bottom of the window
  5. Open file configuration “Power_RX_Configuration.srfs” (File/Open Cfg)

Figure 4: Smart RF Studio RX Window

  1. Click on the Start Button
  1. On laptop “A” start the transmission of the packets by clicking on the button “Start”

Figure 5: Start Button

  1. Record the power consumption during transmission on the oscilloscope
  2. Zoom on one of the sequence during which the transceiver is sending a packet and record the maximum value of current
  3. Record the exact value of the voltage
  4. Calculate the maximum power consumption and record it.
  5. Repeat Steps 1 to 15 with Module A as the receiver (Open “Power_RX_Configuration.srfs”) and module B as the transceiver (Open “Power_TX_Configuration.srfs”) to calculate the maximum power consumption during the reception.

Results

Date: _____1/28/11______Engineer Initials: ___RT______

Pass / Fail Criteria: Power consumption less than 5W

Measured Power Voltage during transmission: ____3.7V______

Maximum Measured Current Consumption during transmission:____27.45mA______

Maximum Power Consumption during transmission: _____102mW______Result: Pass / Fail

Measured Power Voltage during reception: ______3.7V______

Maximum Measured Current Consumption during reception:____26.25mA______

Maximum Power Consumption during reception: _____97mW______Result: Pass / Fail