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DRV2605L Auto Calibration Issues

Other Parts Discussed in Thread: DRV2605L

I am encountering issues with auto calibration with two separate motors. I will describe the experience with each motor separately. The circuit used is identical to Figure 58 in the DRV2605L datasheet, with the exception that PWM is not employed, only internal trigger and the built-in waveform library. VDD is 3.3V. 

In each case, the DRV2605L is configured for ERM in open-loop mode. All defaults are taken. 

1) ERM #1

Manufacturer: Precision Microdrives

Model: 340-121

Datasheet: https://catalog.precisionmicrodrives.com/order-parts/datasheet/304-121-5mm-vibration-motor-11mm-type

Rated Operating Voltage: 3V

Max. Operating Voltage: 3.6V

Terminal Resistance: 34.5 Ohm

To perform the auto calibration the registers are set as follows: 

0x16: 141

0x17: 166

This results in a failure of the auto calibration. If 0x16 is brought down to 128, however, the auto calibration succeeds and waveforms play without any diagnostic errors. 

I am unclear as to why the operating voltage needs to be reduced in order for the part to calibrate. 

2) ERM #2

Manufacturer: Precision Microdrives

Model: 307-100

Datasheet: www.precisionmicrodrives.com/.../307-100-9mm-vibration-motor-25mm-type

Rated Operating Voltage: 3V

Max. Operating Voltage: 3.6V

Terminal Resistance: 5.5 Ohm

To perform the auto calibration the registers are set as follows: 

0x16: 141

0x17: 166

With these values, calibration fails. The only way to pass calibration is to dramatically lower the operating/max voltage, such as using the power on defaults. Even once this is done, however, any attempt to play a waveform succeeds, but then results in the OC_DETECT set to 1. 

The manufacturer suggested this may be related to the terminal resistance. 

Thank you, 

Karl

  • Hi Karl,

    We are reviewing this and will get back to you shortly. Thanks!

    -Brian
  • Karl,

    On ERM #1, could you please provide a complete register dump of all the registers?

    Any oscilloscope captures of the AutoCAL will help. From what I can tell, it looks like the Back Emf is too high.

    On ERM#2 the DCResistance is too low. We require at least 8ohm load for operation.

    Please let  us know if you have any questions.

    Regards,

    Gautham Ramachandran

    Apps. Engineer - Haptics.

  • I've included 5 register dumps. A power on reset dump, a pre calibration at 0x16 set to 141 with corresponding post calibration and scope capture, and a pre/post calibration at 0x16 set to 129 with corresponding scope capture.

    Understood, regarding the second ERM.  

    Reset Dump:

    0x00 0xE0

    0x01 0x40

    0x02 0x00

    0x03 0x01

    0x04 0x01

    0x05 0x00

    0x06 0x00

    0x07 0x00

    0x08 0x00

    0x09 0x00

    0x0A 0x00

    0x0B 0x00

    0x0C 0x00

    0x0D 0x00

    0x0E 0x00

    0x0F 0x00

    0x10 0x00

    0x11 0x05

    0x12 0x19

    0x13 0xFF

    0x14 0x19

    0x15 0xFF

    0x16 0x3E

    0x17 0x8C

    0x18 0x0C

    0x19 0x6C

    0x1A 0x36

    0x1B 0x93

    0x1C 0xF5

    0x1D 0xA0

    0x1E 0x20

    0x1F 0x80

    0x20 0x33

    0x21 0xAF

    0x22 0xFB

    Pre-Calibration (Fail/141):

    0x00 0xE0

    0x01 0x07

    0x02 0x00

    0x03 0x01

    0x04 0x01

    0x05 0x00

    0x06 0x00

    0x07 0x00

    0x08 0x00

    0x09 0x00

    0x0A 0x00

    0x0B 0x00

    0x0C 0x00

    0x0D 0x00

    0x0E 0x00

    0x0F 0x00

    0x10 0x00

    0x11 0x05

    0x12 0x19

    0x13 0xFF

    0x14 0x19

    0x15 0xFF

    0x16 0x8D

    0x17 0xA6

    0x18 0x0C

    0x19 0x6C

    0x1A 0x36

    0x1B 0x93

    0x1C 0xF5

    0x1D 0xA0

    0x1E 0x20

    0x1F 0x80

    0x20 0x33

    0x21 0xAF

    0x22 0xFB

     


     

    Post-Calibration (Fail/141):

    0x00 0xE8

    0x01 0x07

    0x02 0x00

    0x03 0x01

    0x04 0x01

    0x05 0x00

    0x06 0x00

    0x07 0x00

    0x08 0x00

    0x09 0x00

    0x0A 0x00

    0x0B 0x00

    0x0C 0x00

    0x0D 0x00

    0x0E 0x00

    0x0F 0x00

    0x10 0x00

    0x11 0x05

    0x12 0x19

    0x13 0xFF

    0x14 0x19

    0x15 0xFF

    0x16 0x8D

    0x17 0xA6

    0x18 0x0C

    0x19 0x6C

    0x1A 0x36

    0x1B 0x93

    0x1C 0xF5

    0x1D 0xA0

    0x1E 0x20

    0x1F 0x80

    0x20 0x33

    0x21 0x95

    0x22 0xFB

    Pre-Calibration (Pass/129):

    0x00 0xE0

    0x01 0x07

    0x02 0x00

    0x03 0x01

    0x04 0x01

    0x05 0x00

    0x06 0x00

    0x07 0x00

    0x08 0x00

    0x09 0x00

    0x0A 0x00

    0x0B 0x00

    0x0C 0x00

    0x0D 0x00

    0x0E 0x00

    0x0F 0x00

    0x10 0x00

    0x11 0x05

    0x12 0x19

    0x13 0xFF

    0x14 0x19

    0x15 0xFF

    0x16 0x81

    0x17 0xA6

    0x18 0x0C

    0x19 0x6C

    0x1A 0x36

    0x1B 0x93

    0x1C 0xF5

    0x1D 0xA0

    0x1E 0x20

    0x1F 0x80

    0x20 0x33

    0x21 0xAB

    0x22 0x5A

    Post Calibration (Pass/129):

    0x00 0xE0

    0x01 0x07

    0x02 0x00

    0x03 0x01

    0x04 0x01

    0x05 0x00

    0x06 0x00

    0x07 0x00

    0x08 0x00

    0x09 0x00

    0x0A 0x00

    0x0B 0x00

    0x0C 0x00

    0x0D 0x00

    0x0E 0x00

    0x0F 0x00

    0x10 0x00

    0x11 0x05

    0x12 0x19

    0x13 0xFF

    0x14 0x19

    0x15 0xFF

    0x16 0x81

    0x17 0xA6

    0x18 0x10

    0x19 0x7E

    0x1A 0x34

    0x1B 0x93

    0x1C 0xF5

    0x1D 0xA0

    0x1E 0x20

    0x1F 0x80

    0x20 0x33

    0x21 0x96

    0x22 0x5A

    Thanks, 
    Karl

  • Hello, gentle query to see if there's any news on this issue. 

    Thanks!

    Karl