I am wanting to use a XR-8038 as a signal generator to control an IGBT transistor. I need a positive bias to turn the transistor on and a negative bias to turn the resistor off. I need to do this at 20KHz, 28KHz and 40KHz.
I have the XR-8038 wired to a +/-12V power supply, and get very nice square wave output. The output is 0V to+12V when the ground of the oscilloscope probe is grounded to the common, and -12V to 0V when the probe is grounded to the negative power supply. The circuit is wired according to the Generalized Test Circuit on the datasheet.
**broken link removed**
The question is, how do I get a square wave that is +12V to -12V, or shift the wave to +6V to -6V?
Look at figure 1 on page 2 of the document you linked. The output driver is connected to common, and so you can't get -12V swings.
Try connecting a PNP transistor, like a 2n3906. Emitter to +12V, base thru 2.2K resistor to out generator output, collector through a 4.7k resistor to -12V.
Look at figure 1 on page 2 of the document you linked. The output driver is connected to common, and so you can't get -12V swings.
Try connecting a PNP transistor, like a 2n3906. Emitter to +12V, base thru 2.2K resistor to out generator output, collector through a 4.7k resistor to -12V.
This guy got a symetrical output about 0 from his 8038. Its only +/- 5v but you ought to be able to tweak the output op-amp to get the +/- 6v you require.