Use USB_DAQ to Complete the Calibration of PGA308 EVM

Iven Xu

Mar. 13th, 2013

Thanks to Ian Williams

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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

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a) 4-wire voltage output mode

a) 4-wire voltage output mode:

• USB_DAQ Board Default Configuration:

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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.

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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.

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• About the OTP Program, note that you only have 4 times. So before your calibration is completed, do not use OTP program.

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a) 4-wire voltage output mode:

a) 4-wire voltage output mode:

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b) 3-wire voltage output mode

b) 3-wire voltage output mode:

• USB_DAQ Board Default Configuration:

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b) 3-wire voltage output mode:

• PGA308 EVM Default Configuration:

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b) 3-wire voltage output mode:

• Pre-cal file : pre_OW_to_vo_4p096.csv

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c) Current output mode

c) Current output mode:

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• USB DAQ Configuration

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.

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c) Current output mode:

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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.

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c) Current output mode:

• We can use

the Graph to

monitor the

output.

Also, we can

use Multi-meter

to monitor the

output.

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• About the OTP Program, note that you only have 4 times. So before your calibration is completed, do not use OTP program.

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c) Current output mode:

Multi-Calibration principle of PGA308:

• Need to update later.

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Thanks!

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

“pre_vout_4p096.csv”

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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.

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

then click “Save”.

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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):

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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.

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