I am working on creating an AM sine wave utilizing an Agilent 33250A Function Generator. I would like to modulate the sine wave using an external digital stimulus that I am generating with a Xilinx Spartan 3 development kit to produce and ASK (amplitude shift keyed = modulation depth of 100%) signal. My problem is this:
The spartan3 dev kit has a voltage level of 3.3V on output ports when high and 0V on output ports when low (digital CMOS levels). The external modulation input of the 33250A requires a -5V to 5v full-scale signal. Therefore I must level shift the output of the spartan board to -5volts when low, and +5 volts when high to achieve a modulation depth of 100% for ASK. As my modulation signal is digital, I don't really care about the inbetweens.
More simply, I have a digital signal that is either 0V or 3.3V. When the signal is 0V, I want to run it through a converter that outputs -5V. When the signal is 3.3V, I want it rasied to 5V.
Suggestions? I have access to both a split voltage (-20 to +20) power supply and am interested in any transister/op-amp solutions and IC solutions that may exists.
Cheers,
Matt
The spartan3 dev kit has a voltage level of 3.3V on output ports when high and 0V on output ports when low (digital CMOS levels). The external modulation input of the 33250A requires a -5V to 5v full-scale signal. Therefore I must level shift the output of the spartan board to -5volts when low, and +5 volts when high to achieve a modulation depth of 100% for ASK. As my modulation signal is digital, I don't really care about the inbetweens.
More simply, I have a digital signal that is either 0V or 3.3V. When the signal is 0V, I want to run it through a converter that outputs -5V. When the signal is 3.3V, I want it rasied to 5V.
Suggestions? I have access to both a split voltage (-20 to +20) power supply and am interested in any transister/op-amp solutions and IC solutions that may exists.
Cheers,
Matt