: Sombody knows a good way to get convert an unbalaced 5V signal to a balanced 5V signal? Just a simlpe little circuit that handles 250KHz?
Not enough info. But, assuming that you mean an unbalanced 5v (0 to 5v) digital signal to a balanced 10 volt peak to peak (+5v to -5v) digital signal, just use a 1488 RS232 transmitter chip.
Power the chip with +5v on pin 14 and -5v on pin 1. Ground pin 7
unbalance input goes to pin 2
balanced output from pin 3
If on the other hand, you mean unbalance 5v (0v to 5v) digital to two balanced 5v (0v to 5v, 180 degree phase relationship), use any logical inverter like a 7400.
unbalanced to to inverter input pin of inverter.
in-phase output comes from same input pin of inverter.
out-of-phase output comes from output pin of inverter.
But if, on the third hand(?), you are talking about an analog signal, look at fig 1-27 on this page:
For the circuit to be reasonably effective up to 250 KHz, I suggest low values for r2 and r3, perhaps 330 ohms each. Make r1 and r4 3300 ohms each. Q1 is any general purpose 500-600 milliwatt audio transistor like the 2n3904. Vcc should be 15 to 20 volts. The capacitors will depend on the output impedance and required minimum freq, but 50 uf should get you in the ball park.