LM4874

LM4874 Boomer 2.1W Differential Input, BTL Output Stereo Audio Amplifier with Selectable Gain and Shutdown August 2002 LM4874 2.1W Differential Input, BTL Output Stereo Audio Amplifier with Selectable Gain and Shutdown General Description The LM4874 features differential stereo inputs, BTL (bridgetied load) outputs, and four externally selectable fixed gains. Operating on a single 5V supply, the LM4874 delivers 1.2W, 1.9W, or 2.1W (typ) of output power to an 8Ω, 4Ω, or 3Ω BTL load (Note 1), respectively, with less than 1% THD+N. The LM4874’s gain is selected using two digital inputs. The nominal gain values are 6dB, 10dB, 15.6dB, and 21.6dB. The LM4874 is designed for notebook and other handheld portable applications. It delivers high quality output power from a surface-mount package and requires few external components. Other features include an active-low micropower shutdown mode input and thermal shutdown protection. j BTL output power RL = 8Ω, VDD = 5.0V, and THD+N = 1% j Micropower shutdown current j PSRR ( @ 1kHz, VDD = 5V, (Fig.1)) 1.2W (typ) 0.1µA (typ) 62dB (typ) Features n n n n n n n Fully differential input and output Internal gain set: 6dB, 10dB, 15.6dB, and 21.6dB Improved ’click and pop’ suppression Thermal shutdown protection circuit Ultra low current micropower shutdown mode 3.0V to 5.5V operation Available in space-saving exposed-DAP TSSOP package Key Specifications j BTL output power Applications 2.1W (typ) 1.9W (typ) n Notebook computers n PDAs n Po...