Using GS6300 charger IC as an adjustable stepdown.

I got quite a bunch of these thingies some time ago, so it was just the time to get the fun started. At least I needed a car charger for my tablet badly. The wall plug is said to provide 9 volts up to 2,5 Amps. So GS6300 3 Amp thing was just what I needed.
The datasheet for the chip sucked: really little detail and only one application circuit. Luckily, the application circuit was quite simple to understand, so with minor modifications I made a small power adaptor for my flytouch II tablet.

Hints: Make sure you use the right core for the inductance: if you pick the wrong core, you’ll get GS6300 to heat up pretty fast at some 500-600mA consumption.
If you get the diode with the wrong trr (reverse recovery time), you’ll get it to overheat and won’t get enough current.
At first I used a 10k POT to adjust the output voltage and got it to be VERY unstable. 1k POT solved the problem.
Tab is connected to the GND pin, so make sure you have some nice’n’big ground polygons do dissipate all the heat, unless you want to attach a heatsink. At big currents it heats up. (a charging tablet + max brightness screen + a 3g modem plugged into the tablet).
There is the photo of the assembled thingie:

Since I didn’t have the car’s smoke’o’plug around, I wired the raw voltage from a 5v dc-dc stepdown I had around.

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