Hi,
I am looking for an audio amplifier capable powering a variety of voice coil motors, down to a low frequency (ideally less than 5Hz). The main requirements are to be able to:
Drive two 4 ohm impedances simultaneously, with a power of up to 20 [W] per voice coil.
Drive a single 8.5 ohm impedance, at up to approx 20 [W].
Drive a single 2 ohm impedance, at 5-15 [W].
Ideally, the amplifier will be available as an EVM to reduce design and manufacturing time for the small quantities we need.
The TPA3118D2 and TPA3116D2 were recommended as suggestions, but datasheets cut off at 20Hz for frequency response.
Would it be possible to use these amplifiers down to a lower frequency, or would it be better to switch to simply using power amplifiers (we've used OPA569 for a custom application in the past)? It looks like THD+N increases significantly for the TPA3116D2 at low frequencies, so perhaps it would be better to use something like the TPA3251D2? Again, low frequency response is not visible on the chart.
I also worry that the EVM could filter out low frequency amplification, but possibly this could be changed by replacing components.low
Thanks,
Tom.