DRV2700: DRV2700EVM with piezo actuator

first_name Karabchvsky

Part Number: DRV2700

I am trying to use DRV2700EVM to drive a piezo actuator (P-602.3SL from PI) with a 3Hz sine wave (Output voltage -20V to 100V) . During operation I can observe drops in VBST probably because boost goes into over current mode .

The actuator is 3.1uF rated . I tried driving a 3.3uF capacitor with the same waveform and there I don't observe any problem.

Is there any issue driving an actuator with DRV2700EVM ?

over 2 years ago

0 Jeff McPherson over 2 years ago

TI__Mastermind 46805 points

Hi,

Typically no, there is no issue driving an actuator. Can you double check that your programed current limit and the boost inductor can support the current you're trying to draw? Refer to section 8.2.1.2.3-4

Thank you,
Jeff McPherson

0 first_name Karabchvsky over 2 years ago

Prodigy 10 points

I have used a standard DRV2700EVM with default current limit and inductor . According to my calculations (Section 8.2.1.2.8 of datasheet) the current through actuator should be 5.8mA and inductor peek at 195mA . While the current limit on EVM is 2.4A

Best regards

Serge

0 Jeff McPherson over 2 years ago in reply to first_name Karabchvsky

TI__Mastermind 46805 points

Hi,

To clarify, are you seeing the boost drop issue with the default actuator? Your original post led me to believe you were using an external actuator. If you could monitor the current and voltage across the load on a scope and share those results that could give information on what may be happening.

Best regards,
Jeff McPherson

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DRV2700: DRV2700EVM with piezo actuator