LM4842 Datasheet | National Semiconductor

Description The LM4842 is a monolithic integrated circuit that provides DC volume control, and stereo bridged audio power amplifiers capable of producing 2W into 4Ω (Note 1) or 2.2W into 3Ω (Note 2) with less than 1.0% THD+N. Boomer ® audio integrated circuits were designed specifically to provide high quality audio while requiring a minimum amount of external ponents. The LM4842 incorporates a DC volume control, stereo bridged audio power amplifiers, new cap-less headphone driver circuit (patent pending), selectable gain or bass boost, and an input mux making it optimally suited for multimedia monitors, portable radios, desktop, and portable puter applications. The LM4842 features an externally controlled, low-power consumption shutdown mode (Shutdown Low), and both a power amplifier and headphone mute for maximum system flexibility and performance. Note 1: When properly mounted to the circuit board, the LM4842MH will deliver 2W into 4Ω. The LM4842MT will deliver 1.1W into 8Ω. See the Application Information section for LM4842MH usage information. Note 2: An LM4842MH that has been properly mounted to the circuit board and forced-air cooled will deliver 2.2W into 3Ω. Key Specifications n PO at 1% THD+N n into 3Ω (MH and LQ) n into 4Ω (MH and LQ) n into 8Ω (MT, MH, and LQ) n Single-ended THD+N at 85m W into 32Ω n Shutdown current (Shutdown Low) 2.2W(typ) 2.0W(typ) 1.1W(typ) 1.0%(typ) 0.2µA(typ) Features n Stereo headphone amplifier mode that eliminates the Output Coupling Capacitors (patent pending) n Advanced “click and pop” suppression circuitry n Acoustically Enhanced DC Volume Control Taper n 2 Channel Stereo Input MUX n System Beep Detect n Stereo switchable bridged/single-ended power amplifiers n Selectable internal/external gain and bass boost n Thermal shutdown protection circuitry Applications n Portable and Desktop puters n Multimedia Monitors n Portable Radios, PDAs, and Portable TVs Connection Diagrams TSSOP Package Top View Order Number...