Posted on Aug 24, 2012 5215
Two pairs of MOSFETs form a bridge that alternately switches current in opposite directions. Two parallel-resonant LC circuits complete the converter. The Ll/C1 combination is resonant at the fundamental frequency; the L2/C2 combination is resonant at the clock frequency`s third harmonic and acts as a trap. Tl and C3 ensure that both halves of the MOSFET bridge are never on at the same time by providing a common delay to the gate drive of each half.
Select the values of R1 and C3 to yield a time constant that"s less than 5% of the clock"s period. You can add an output amplifier for additional buffering and conditioning of the circuit"s sine-wave output.