The LM4781 is a three channel audio amplifier capable oftypically delivering 35W per channel of continuous averageoutput power into an 8Ω load with less than 0.5% THD+Nfrom 20Hz - 20kHz.The LM4781 is fully protected utilizing National’s Self PeakInstantaneous Temperature (°Ke) (SPiKeTM) protection circuitry.SPiKe provides a dynamically optimized Safe OperatingArea (SOA). SPiKe protection completely safeguards theLM4781’s outputs against over-voltage, under-voltage, overloads,shorts to the supplies or GND, thermal runaway andinstantaneous temperature peaks. The advanced protectionfeatures of the LM4781 places it in a class above discreteand hybrid amplifiers.Each amplifier of the LM4781 has an independent smoothtransition fade-in/out mute.The LM4781 can easily be configured for bridge or paralleloperation for higher power and bi-amp solutions.Key Specificationsj Output Power/Channel with 0.5% THD+N,1kHz into 8Ω 35W (typ)j THD+N at 3 x 20W into 8Ω (20Hz - 20kHz) 0.2% (typ)j THD+N at 3 x 20W into 6Ω (20Hz - 20kHz) 0.3% (typ)j THD+N at 3 x 20W into 4Ω (20Hz - 20kHz) 0.5% (typ)j Mute Attenuation 110dB (typ)j PSRR 85dB (min)j Slew Rate 9V/μs (typ)Featuresn SPiKe Protectionn Low external component countn Quiet fade-in/out mute moden Wide supply range: 20V - 70Vn Signal-to-Noise Ratio ≥ 93dB (ref. to PO = 1W)Applicationsn Audio amplifier for component stereon Audio amplifier for compact stereon Audio amplifier for self-powered speakersn Audio amplifier for high-end and HD TVs