Use USB_DAQ to Complete the Calibration of PGA308 EVM

1. Use USB_DAQ to Complete the Calibration of PGA308 EVM Iven Xu Mar. 13th, 2013 Thanks to Ian Williams

2. Agenda • USB_DAQ and PGA308 EVM overview • Calibration principle of PGA308 EVM • Three output mode of PGA308 EVM • 4-wire voltage output mode • 3-wire voltage output mode • Current output mode • Multi-Calibration principle of PGA308

3. a) 4-wire voltage output mode

4. a) 4-wire voltage output mode: • USB_DAQ Board Default Configuration:

5. a) 4-wire voltage output mode: • PGA308 EVM Default Configuration: • T1 and T2 of USB_DAQ need not to connect anything. • Notice only in current output mode, we should connect the +-15V to T2 and 24V to T1.

6. a) 4-wire voltage output mode: • Firstly, we should make sure we have selected “Run out of RAM” in “Block Diagram”: • Then, move to “Calibration”. Make sure the step 1 ~ step 3 as the same of below fig: • Thirdly, click “select Cal Preset” in step 4 and select “pre_vout_4p096.csv” for voltage output. • Then, click “Calibrate” in step 6 and follow the prompted window to change the output of sensor.

7. a) 4-wire voltage output mode: • About the OTP Program, note that you only have 4 times. So before your calibration is completed, do not use OTP program.

8. a) 4-wire voltage output mode:

9. b) 3-wire voltage output mode

10. b) 3-wire voltage output mode: • USB_DAQ Board Default Configuration:

11. b) 3-wire voltage output mode: • PGA308 EVM Default Configuration:

12. b) 3-wire voltage output mode: • Pre-cal file : pre_OW_to_vo_4p096.csv

13. c) Current output mode

14. c) Current output mode: • USB DAQ Configuration

15. c) Current output mode: • PGA308 EVM Configuration * When we want to use current output mode of XTR117: * we should make sure the configuration of PGA308 is in 4-wire voltage output mode; * Because in 3-wire voltage output mode of PGA308, we should turn on/off the Vs of PGA308. But in 3-wire mode, the one-wire and Vout is connect in one junction, so we cannot use one-wire to control the Vs (turn on/off). * conclusion: is we should use 4-wire voltage output for current output.

16. c) Current output mode:

17. c) Current output mode: • Firstly, we should make sure we have selected “Run out of RAM” in “Block Diagram”: • Then, move to “Calibration”. Make sure the step 1 ~ step 3 as the same of below fig: • Thirdly, click “select Cal Preset” in step 4 and select “pre_Iout_4p096.csv” for current output. • Then, click “Calibrate” in step 6 and follow the prompted window to change the output of sensor.

18. c) Current output mode: • We can use the Graph to monitor the output. Also, we can use Multi-meter to monitor the output.

19. c) Current output mode: • About the OTP Program, note that you only have 4 times. So before your calibration is completed, do not use OTP program.

20. Multi-Calibration principle of PGA308: • Need to update later.

21. Thanks!

22. How to create the model file: • (1), click the “Load Preset From….”, select a exist file like “pre_vout_4p096.csv”

23. How to create the model file: • (2), then you can change the value as you want, for example we change the Vref (V) from 4.096 to 4.

24. How to create the model file: • (3), then click the “Save Preset to File”, write a name like “pre_cal.csv”, then click “Save”.

25. How to create the model file: • (4), Then re-click the “Load Preset From…”, select the “pre_cal.csv” we saved in the last step (3):

26. How to create the model file: • (5), then the value should be the same as you just changed in step (2) (we changed Vref from 4.096 to 4). • (6), then click the “OK”, now finished the preset file. • (7), then you can do the calibration in “step 6” of PGA308 software.