LM4802B

Audio Power Amplifier with Boost Converter to Drive Ceramic Speakers November 2004 LM4802B Audio Power Amplifier with Boost Converter to Drive Ceramic Speakers General Description The LM4802B integrates a Boost Converter with an Audio Power Amplifier to drive Ceramic Speakers in portable applications. When powered by a 3V supply, it is capable of forcing 12Vp-p across a 2µF + 30Ω bridge-tied-load (BTL) with less than 1% THD+N. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. The LM4802B does not require bootstrap capacitors, or snubber circuits. Therefore it is ideally suited for portable applications requiring high output voltage and minimal size. The LM4802B features a low-power consumption shutdown mode. Additionally, the LM4802B features an internal thermal shutdown protection mechanism. The LM4802B contains advanced pop & click circuitry that eliminates noises which would otherwise occur during turn-on and turn-off transitions. The LM4802B is unity-gain stable. Its gain is set by external resistors. Key Specifications j Quiescent Power Supply Current j BTL Voltage Swing 12mA (typ) (2µF + 30Ω load, 1% THD+N, VDD = 3V) j Shutdown Current 12Vp-p (typ) 2µA (max) Features n Pop & click circuitry eliminates noise during turn-on and turn-off transitions n Low, 2µA (max) shutdown current n Low, 12mA (typ) quiescent current n 12Vp-p mono BTL output, load = 2µF + 30Ω, VDD = 3V n Short...