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  • TI Thinks Resolved

DRV2625: DRV2625 VDD versus LRA waveform Vpp

Intellectual 940 points

Replies: 31

Views: 279

Part Number: DRV2625

Hi

We set overdrive voltage = 3Vpeak as attached excel

But we find when we change DRV2625 VDD voltage, the waveform Vp/Vpp also change as below table

Is it normal? Since as I know the Vp should limit at Vpeak setting

Thank you~~

Haptic_VDD(V) Waveform Vp(V) Waveform Vpp(V)
4.4 3.42 6.84
4.2 3.34 6.68
4 3.3 6.6
3.8 3.22 6.48
3.6 3.14 6.32
3.5 3.1 6.2
3.4 3.06 6.12

8132.DRV2624 and DRV2625 Configuration Tool and Design Equations-AWA_modified.xlsx

  • In reply to Carson Allen:

    Hi Carson:

    We decrease sampling rate to 5K/S and find the PWM noise disappear

    Our setting is rated voltage = 1.8V, clamp voltage = 3V

    We change VDD 3.6V and 4.4V and the Vpp still change as below chart(VDD=3.6V, Vpp=6.192V; VDD=4.4V, Vpp=6.84V)

    What is your VDD setting in the previous test you provide?

    And please help change VDD=3.6V and 4.4V on you side to see Vpp status

    And if your test, Vpp won't change with VDD, which setting or anything we need check? Did you check our setting file(excel)?

    Thank you~~

    VDD=3.6V

    VDD=4.4V

  • In reply to Carson Allen:

    Hi Carson:

    We decrease sampling rate to 5K/S and PWM noise disappear

    Our setting is rated voltage = 1.8V , clamping voltage = 3V

    We change VDD 3.6V and 4.4V but Vpp still change (VDD 3.6V, Vpp=6.192V; VDD 4.4V, Vpp=6.84V)

    What is your VDD voltage setting at previous test you provide?

    And please help do test that change VDD 3.6V and 4.4V on your side to see Vpp status

    If your test, Vpp won't change, so which setting or anything that we need check? Did you help check our setting file(excel) ?

    Thank you~~

    VDD=3.6V

    VDD=4.4V

  • In reply to Poki Huang:

    Hey Poki,

    Yes I will perform the test today get back with results for you

    Best,

    Carson

  • In reply to Carson Allen:

    Hi Carson:

    Sorry, I need correct our setting for below table is 2.82 Vpeak not 3V peak

    Haptic_VDD(V) Waveform Vp(V) Waveform Vpp(V)
    4.4 3.42 6.84
    4.2 3.34 6.68
    4 3.3 6.6
    3.8 3.22 6.48
    3.6 3.14 6.32
    3.5 3.1 6.2
    3.4 3.06 6.12

    And I summary my questions as below and please help do test on your side

    1. The waveform Vp/Vpp increase with VDD, please help do test that change VDD 3.6V and 4.4V on your side to see Vp/Vpp status

    2. The waveform Vp/Vpp is not limited by setting Vpeak, please help do test that change Vpeak 2.82V and 2.55V on your side to see Vp/Vpp status

    Thank you~~

    Poki

  • In reply to Poki Huang:

    So I did the same test as you with clamp voltage at 2.82

    Vdd = 4.4  Vpeak = 2.68

    Vdd = 4.2 Vpeak = 2.68

    Vdd = 4.0  Vpeak = 2.66

    Vdd = 3.8  Vpeak = 2.65

    Vdd = 3.6  Vpeak = 2.63

    Vdd = 3.4  Vpeak = 2.63

    So unlike yours, my Vpeak doesnt change drastically with Vdd but still does a little and it also does not surpass the clamp voltage of 2.82.

    Let me ask you a few questions:

    1. So, are you making sure to run auto-calibration everytime the power supply is changed? You should probably not load in old settings from a different power supply

    2. Is this happening across consistently across chips or all your readings from a single PCB?

    3. Are you making sure what ever you are writing to the OD_CLAMP register is what you think you are putting it? I would read the reigster to make sure

    4. I also noticed from past photos you are measuring off cardboard, are you still doing that because the material can add more noise to readings?

    5. Are these measurements with or without an LRA attached or with the appropriate output filter for recording?

    Answering those will help get to the source of the problem here

    Best,

    Carson

  • In reply to Carson Allen:

    Hi Carson:

    1. We do calibration but the Vpeak still not fix and under OD_CLAMP, but we find after calibration OD_CLAMP from 0x89 to 0x92 (2.82V to 3V), waveform as below

    VDD=3.4V,   before calibration, OD_CLAMP=0x89 (2.82V) , Vpeak=3.024V

    VDD=3.4V,  after calibration, OD_CLAMP=0x92 (3V) , Vpeak=3.168V

    VDD=4.4V,  before calibration, OD_CLAMP=0x89 (2.82V) , Vpeak=3.348V

    VDD=4.4V,  after calibration, OD_CLAMP=0x92 (3V) , Vpeak=3.492V

    2. All chips has the same situation, not only one

    3. As item1, I read registor after change VDD and calibration

    4. We don't use cardboard, present setting as below picture

    5. With attached LRA and use DRV2605 EVB low pass filter(100Kohm, 470PF)

    Questions as below

    1. Your waveform is strong click, Rated voltage =1.8V right?

    2. Could you provide your sample code for us?

    3. Could you provide excel file ("DRV2624 and DRV2625 Configuration Tool and Design Equations") and fill in the setting of your test?

    4. How do you change your VDD? External supply to DRV2625 EVB J7.1 pin?

    5. Not only Vpeak change with VDD but also Vpeak can't be clamp under OD_CLAMP, so anything we can check about HW or SW?

    Thank you~~

    Poki

  • In reply to Poki Huang:

    Hey Poki,

    Yes I am using Strong click with 1.8V rated voltage

    I am not directly programming the chip, I am suing the DRV2625EVM with haptics control console where I switch power using the designated pins on the board.

    I'm sorry but what do you mean by HW and SW?

    Can you provide the details of the LRA you are using and possibly share the code you are using so I can have a colleague recreate your exact set-up without the EVM?

    Best,

    Carson

  • In reply to Carson Allen:

    CZ-EACQ SPEC_Draft1.1_200716_AWA.pdfHi Carson:

    1. I attached LRA spec. as above, and the code we are using will provide to you later

    2. I mean at present situation, our Vpeak can't be controlled under OD_CLAMP setting, so anything related this issue we can check?

    3. Could you provide the waveforms you measured below?

    Vdd = 4.4  Vpeak = 2.68

    Vdd = 4.2 Vpeak = 2.68

    Vdd = 4.0  Vpeak = 2.66

    Vdd = 3.8  Vpeak = 2.65

    Vdd = 3.6  Vpeak = 2.63

    Vdd = 3.4  Vpeak = 2.63

    Thank you

    Poki

  • In reply to Poki Huang:

    Hi Carson:

    I list our code as below, please help check, thank you~~

    Poki

    #define DRV2625_ID 0x00                                                                              
      #define DRV2625_STATUS 0x01                                                                          
      #define DRV2625_MODE 0x07                                                                            
      #define DRV2625_CONFIG_08 0x08                                                                      
      #define DRV2625_GO 0x0C                                                                              
      #define DRV2625_LIBRARY 0x0D                                                                        
      #define DRV2625_WAVE_SEQ_1 0x0F                                                                      
      #define DRV2625_WAVE_SEQ_2 0x10                                                                      
      #define DRV2625_WAVE_SEQ_3 0x11                                                                      
      #define DRV2625_WAVE_SEQ_4 0x12                                                                      
      #define DRV2625_WAVE_SEQ_5 0x13                                                                      
      #define DRV2625_WAVE_SEQ_6 0x14                                                                      
      #define DRV2625_WAVE_SEQ_7 0x15                                                                      
      #define DRV2625_WAVE_SEQ_8 0x16                                                                      
      #define DRV2625_RATED_VOLTAGE 0x1F                                                                  
      #define DRV2625_OD_CLAMP 0x20                                                                        
      #define DRV2625_AUTO_CAL_COMP 0x21                                                                  
      #define DRV2625_AUTO_CAL_BEMF 0x22                                                                  
      #define DRV2625_FEEDBACK_CONTROL 0x23                                                                
      #define DRV2625_RATED_VOLTAGE_CLAMP 0x24                                                            
      #define DRV2625_OD_CLAMP_LVL1 0x25                                                                  
      #define DRV2625_OD_CLAMP_LVL2 0x26                                                                  
      #define DRV2625_CONTROL1 0x27                                                                        
      #define DRV2625_CONTROL2 0x28                                                                        
      #define DRV2625_CONTROL3 0x29                                                                        

      #define DRV2625_AUTO_CAL_TIME 0x2A  

     

    #define OP_MODE_AUTO_CALIBRATION 3   

      #define OP_MODE_WAVEFORM_SEQ 1        

      #define MOTOR_DRIVE_TIME_SETTING 0x10        

      #define DRV2625_LIB_ENABLE (1<<7)       

      #define HAPTIC_TYPE_FIRST 1                                                                                                                                                                                                                                                                                                                              

      #define MOTOR_RATED_VOLTAGE_SETTING 0x46                                                            
      #define MOTOR_OD_CLAMP_SETTING 0x75

     

     


    static int auto_calibration(calibration_data* data)                                                  
      {                                                                                                    
          reg_write(DRV2625_MODE, OP_MODE_AUTO_CALIBRATION);                                              
          reg_write(DRV2625_FEEDBACK_CONTROL, 0x38);                                                      
          reg_write(DRV2625_RATED_VOLTAGE, MOTOR_RATED_VOLTAGE_SETTING);                                  
          reg_write(DRV2625_OD_CLAMP, MOTOR_OD_CLAMP_SETTING);                                            
          reg_write(DRV2625_AUTO_CAL_TIME, 0x02);                                                          
          reg_write(DRV2625_CONTROL1, MOTOR_DRIVE_TIME_SETTING);                                          
          reg_write(DRV2625_CONTROL2, 0x11);                                                              
          reg_write(DRV2625_CONTROL3, 0x0C);                                                              
          reg_write(DRV2625_GO, 0x01);                                                                    
          poll_go();   

    }

     

    init {

          reg_write(DRV2625_RATED_VOLTAGE, MOTOR_RATED_VOLTAGE_SETTING);               
          reg_write(DRV2625_OD_CLAMP, MOTOR_OD_CLAMP_SETTING);

          set_waveform_sequencer_mode();                                                                   

    }

     

      static void set_waveform_sequencer_mode()                                                            
      {                                                                                                    
          reg_write(DRV2625_LIBRARY, DRV2625_LIB_ENABLE);                                                  
          reg_write(DRV2625_WAVE_SEQ_1, HAPTIC_TYPE_FIRST);                                                
          reg_write(DRV2625_MODE, 0x40 | (TRIG_PIN_FUNC_PULSE << 2) | OP_MODE_WAVEFORM_SEQ);              
      }

  • In reply to Poki Huang:

    Hi Carson:

    I use DRV2625 EVB but the situation is the same, the Vpeak is higher than OD_CLAMP and Vpeak change with VDD

    I do calibration everytime after change VDD level

    Is there any other setting I need to do first?

    Thank you~~

    Poki 

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