Use USBDAQ to Complete the Calibration of PGA

Use USB_DAQ to Complete the Calibration of PGA 308 EVM Iven Xu Mar. 13 th, 2013 Thanks to Ian Williams 1

Agenda • USB_DAQ and PGA 308 EVM overview • Calibration principle of PGA 308 EVM • Three output mode of PGA 308 EVM – 4 -wire voltage output mode – 3 -wire voltage output mode – Current output mode • Multi-Calibration principle of PGA 308 2

a) 4 -wire voltage output mode 3

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

a) 4 -wire voltage output mode: • PGA 308 EVM Default Configuration: • T 1 and T 2 of USB_DAQ need not to connect anything. • Notice only in current output mode, we should connect the +-15 V to T 2 and 24 V to T 1. 5

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_4 p 096. csv” for voltage output. • Then, click “Calibrate” in step 6 and follow the prompted window to change the output of sensor. 6

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. 7

a) 4 -wire voltage output mode: 8

b) 3 -wire voltage output mode 9

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

b) 3 -wire voltage output mode: • PGA 308 EVM Default Configuration: 11

b) 3 -wire voltage output mode: • Pre-cal file : pre_OW_to_vo_4 p 096. csv 12

c) Current output mode 13

c) Current output mode: • USB DAQ Configuration 14

c) Current output mode: • PGA 308 EVM Configuration * When we want to use current output mode of XTR 117: * we should make sure the configuration of PGA 308 is in 4 -wire voltage output mode; * Because in 3 -wire voltage output mode of PGA 308, we should turn on/off the Vs of PGA 308. 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. 15

c) Current output mode: 16

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_4 p 096. csv” for current output. • Then, click “Calibrate” in step 6 and follow the prompted window to change the output of sensor. 17

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

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. 19

Multi-Calibration principle of PGA 308: • Need to update later. 20

Thanks! 21

How to create the model file: • (1), click the “Load Preset From…. ”, select a exist file like “pre_vout_4 p 096. csv” 22

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. 23

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

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): 25

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 PGA 308 software. 26