Stuart,
Thanks glad I could help!
For ERMs:
- It is possible to drive multiple actuators
- During ERM drive the device is in open-loop, so there is no special feedback, so functionally driving multiple ERMs is not a problem.
- The ERMs should be setup in parallel
- Ensure the equivalent resistance of all the ERMs is greater than 8 ohms, which is the minimum load impedance for the device.
For LRAs,
- It is not recommended to drive multiple actuators
- This is due to the fact that the DRV2603 senses the resonant frequency (auto-resonance tracking) of an individual LRA and then drives it with that frequency. If there are multiple actuators it may not be able to lock onto one frequency.
- That said, if the LRA actuator resonance frequency error is small than the driver may be able to drive both with sufficient force. This really comes down to setting it up in a lab and testing the acceleration of the actuators.
- Again, ensure that the equivalent resistance is greater than 8 ohms.
Thanks,
Brian