PGA411-Q1: Resolver sensor Interface IC not showing updated angle

Zubair,

The first thing to do is check if AOUT is changing as you rotate the resolver sensor. If AOUT is changing, then the tracking loop is updating correctly and there is a problem with your interface code. If AOUT is not changing, then try the following debugging steps:

You will need to check if a fault has occurred. With the default register settings, most faults will cause the PGA411-Q1 to turn off the exciter amplifier and tracking loop. There are a few ways to debug if this is the issue.

1.) Check the state of the fault pin (note that it needs a pull-up resistor). If it is High/Hi-Z, then a fault has occurred.
2.) Check that the exciter outputs are active on the oscilloscope (OE1/OE2). If these are working, then the tracking loop should also be running.
3.) Keep FAULTRES low for your initial testing. This will ignore all faults and keep the device running. Note that when keeping FAULTRES low, it is possible to damage the PGA411 by shorting the boost output, OE1, or OE2 pins.

If it appears that a fault is not causing the issue, then you should double check your signal levels.

1.) Check that OSIN/OCOS are within 1Vpp to 3Vpp maximum.
2.) Check that the signal at the IE1 and IE2 pins is within 0.5 to 4.5V.

Finally, what interface are you using to read the angle information? SPI, parallel, or emulated encoder outputs?

Thanks,

-Clancy

Hi,

Thanks for the updates.

I am using SPI interface.

I am able to correctly read the registers values. Also before reading the angle value. I am checking the device state which shows me that device is in active state.

I have tried it for both Vrms 4 V as well as 7 V by configuring the register value.

I have disabled the faults as for now.

Can you please share the initializations steps so that I can verify my code. I have followed TI basic initialzation code as give in document.

Device communication is fine. While angle value not getting updated. Probably Resolver sensor not getting excited correctly or else.

Zubair,

Do you have access to an oscilloscope? You should check that the analog signals look OK.

- OE1 and OE2
- IE1 and IE2
- IZ1, IZ2, IZ3, and IZ4
- OCOS and OSIN

The "Troubleshooting Guide for PGA411-Q1" includes images of what these signals typically look like:
www.ti.com/.../slaa688.pdf

Have you seen the sample code available in the automotive TI design?
www.ti.com/.../TIDA-00796

And this app note explains the code from the TIDA-00796 in a little more detail:
www.ti.com/.../slaa708.pdf

Thanks,

-Clancy

Hi,
I have one new thing very weired, which is my device when gets power up, It always shows that it is in active state & I am successfully able to do communication with PGA as I am reading DEV_CLCRC register default value, The value it gives me during reading is accurate, But when I tried device to put into diagnostics, It does not goes into DIAG mode, It always remain in active mode. Even without initializing the minimum code.

Hi,

    Now I am reading the resolver angle data, It is always giving me different data, even without rotating the resolver sensor. 

I have checked device state, It is in Active mode & No Fults. Tracking loop is also enabled as well internal exciter is enabled. 

Do I have wrong pinout connections of resolver with Pga or any other issue? Really appreciate your feedback on it. Thanks

Zubair,

Can you share a few things?

- register settings that you are using
- schematic of your board if not using the EVM (you can send this to me privately)
- waveform captures of:
-OSIN/OCOS
- IE1/IE2
- IZ1/IZ2/IZ3/IZ4

To resolve the interface issues, can you also send me a list of the SPI commands you are sending to the PGA411?

Thanks,

-Clancy