Hello,
We have built a custom board designed from your reference design for the 24V solenoid. However, we are using a 28V solenoid and are not powering any other circuitry from the voltage going to Vin of the DRV110.
The Excel tool (thanks for this by the way) was used to provide values for the components. The data is shown below:
The schematic for our board is shown below. Note there are a number of Do Not Installs:
We were surprised that instead of a 1.33A hold current, we are getting about 0.8A at 28V. More surprising was that as we ramped the voltage down (28, 24, 20, etc), the current increased. At 18.8V, the 1.33A seemed to be achieved. Further decreasing this voltage showed the current dropping again.Our solenoid is rated typically for 24V and has about a 9 ohm resistance.
The variation with solenoid voltage was very confusing. The only apparent influence would be from the DRV110A_VIN power. No other pins are referenced to the incoming power supply.
Does anyone have any similar experience or suggestions?
Thanks!