The schematic is the first step and should be based on this modified version of the one supplied in the datasheet:
The above should be modified to include the single control line sub-circuit shown below:
In addition to that, I want to include an RC Zobel network on the output, and possibly a low resistance series inductor too:
Finally we need to provide an LED drive, as the datasheet specifies 10k pullups to 5V (not currently available, but perhaps required) which isn't strong enough to brightly light a red LED. A simple zener supply should be OK. Rail voltage will be 45V peak or so. 2.4k with 5.1V zener will make 18mA available and dissipate 1W continuously. Perhaps a linear part would be better, or a 20k resistor just to allow the IC to provide a signal, but then what to drive the LED? Ideas welcome :-)
Values recommended for a single module are as follows:
And my annotated version is here, showing what I plan to mess with for various reasons:
After the schematics are complete and agreed upon we can move on to layout, and something similar to their design, possibly enhanced/redesigned for two layers, will be good:
This is my tweaked variant of the chip pin out diagram:
I still need to figure out the input circuit values, and Zobel values and decide on an output inductor, or not. I also need to pick up the parts to use, so the footprints can be obtained from them. Especially the 1000uF+ decouple caps.
Comments welcome :-)
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