I'd like to build about 12 units (too few to make custom PCBs, enough for time, cost and inexperience to be a concern) of a device mapping an analog (voltage, not PWM) input range of 0 to 5V to an output range of e.g. -12 to +12V, ~2W, with 0 output around 2.5V input. That probably has a name, but I have not found it.
Doesn't have to be exactly linear.
I can approximate such a device with a microcontroller (ATtiny85) and an H-bridge (L9110S), but with both input and output quantized at such a poor resolution (10 and 8 bit, typically), the result is too twitchy for what I'm driving (not motor, exactly, but a similar enough device using electromagnets).
Researching similar devices that are already being manufactured, I came across something almost perfect:digital audio amplifiers.
PAM8403-based boards are super cheap, assembled, efficient, have 2 H-bridges each, v.fast switching frequency, and drive stepper motors beautifully. And there are stronger amps available.
However, they achieve their functionality via AC coupling. So, a DC motor moves in response to voltage change, not absolute level. Without the input caps, they don't seem to work at all (at least, I couldn't make them)
What is the suggested solution? H-bridge-based motor driver + some magic on the 2 input pins? Modifying an amp's input? An analog circuit?