Class-D Audio-Amp Driver Delivers Over 90% Efficiency June 27, 2008
For driving Class-D audio amplifiers, the MD7120 N-channel, full-bridge power MOSFET connects directly to a 200V supply and can drive over 100W of output with a 90% efficiency. The device provides a range of output voltages from 12V to 200V and specifies a dead time of ±5 ns, matching rise or fall times of less than 30 ns with a typical 1-nF load. Drive for the N-channel MOSFETs is from normal logic level inputs via directly coupled level translators. Other integrated features include control logic, the level translators, a bootstrap-powered high-side gate driver, and over-temperature, under-voltage, and current protection circuits. Thresholds of current protection for both the high and low sides are resistor-programmable. Available in a 32-lead QFN package (MD7120K6-G), pricing is $5.20 each/1,000. SUPERTEX INC., Sunnyvale, CA. (800) 222-9883.
