LM4854 Datasheet | National Semiconductor

Description The unity-gain stable LM4854 is both a mono differential output (for bridge-tied loads, or BTL) audio power amplifier and a single-ended (SE) stereo headphone amplifier. Operating on a single 5V supply, the mono BTL mode delivers 1.1W (typ) to an 8Ω load, 1.7W (typ) to a 4Ω load (Note 1) at 1% THD+N. In SE stereo mode, the amplifier will deliver 85m W to 32Ω loads. The LM4854 features a new circuit topology that suppresses output transients (’click and pops’) and eliminates SE-mode output coupling capacitors, saving both ponent and board space costs. The LM4854 has three inputs: one pair for a two-channel stereo signal and the third for a single-channel mono input. The LM4854 is designed for PDA, cellular telephone, notebook, and other handheld portable applications. It delivers high quality output power from a surface-mount package and requires few external ponents. Other features include an active-low micropower shutdown mode, an "instant-on" low power standby mode, and thermal shutdown protection. The LM4854 is available in the very space-efficient 12-lead micro SMD, exposed-DAP LLP for higher power applications, and TSSOP packages. Note 1: An LM4854LD that has been properly mounted to a circuit board will deliver 1.7W (typ) into a 4Ω load. j SE output power (RL = 32Ω and THD+N = 1.0%) VDD = 3.0V VDD = 5.0V j Micropower shutdown supply current 32m W (typ) 93m W (typ) 0.005µA (typ) 0.05µA (typ) 16µA (typ) 27µA (typ) VDD = 3.0V VDD = 5.0V j Standby supply current VDD = 3.0V VDD = 5.0V j PSRR (f = 1k Hz, 3.0V ≤ VDD ≤ 5.0V, (Fig. 1)) BTL SE 60d B (typ) 66d B (typ) Features n Fast 0.1ms (typ) and 1.0ms (max) turn-on and turn-off time n Eliminates SE amplifier output coupling capacitors n Advanced "click and pop" suppression circuitry n Stereo headphone amplifier mode n Low-power standby and ultra-low current micropower shutdown modes n Thermal shutdown protection circuitry n 2.4V to 5.5V operation n Unity-gain stable n Gain set with external resistors n...