LM48824

The LM48824 is a Class G, ground-referenced stereo headphone amplifier designed for portable devices. The LM48824 features National's ground-referenced architecture, which eliminates the large DC blocking capacitors required by traditional headphone amplifiers, saving board space and minimizing system cost.

The LM48824 takes advantage of National's patent-pending Class G architecture offering power savings compared to a traditional Class AB headphone amplifier. Additionally, output noise is improved by common-mode sensing that corrects for any differences between the amplifier ground and the potential at the headphone return terminal, minimizing noise created by any ground mismatches.

A high output impedance mode allows the LM48824's outputs to be driven by an external source without degrading the signal. Other features include flexible power supply requirements, differential inputs for improved noise rejection, a low power (2.5A) shutdown mode, and a 32-step I 2C volume control with mute function.

The LM48824's superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. The LM48824 is available in an ultra-small 16-bump, 0.4mm pitch micro SMD package (1.69mm x 1.69mm)

Design Tools

The LM48824 is a class G, ground-referenced stereo headphone amplifier designed for portable devices. The LM48824 features National's ground-referenced architecture, which eliminates the large DC blocking capacitors required by traditional headphone amplifiers, saving board space and minimizing system cost.

Features of the LM48824 are:(1)class G power savings;(2)ground referenced headphone outputs eliminates output coupling capacitors;(3)common-mode sense;(4)I2C volume and mode control;(5)high output impedance in shutdown;(6)differential inputs;(7)advanced click-and-pop suppression;(8)low supply current;(9)low THD mode option.

The absolute maximum ratings of the LM48824 can be summarized as:(1):the parameter is supply voltage,the rating is 6,the unit is V;(2):the parameter is storage temperature,the rating is -65 to +150,the unit is ;(3):the parameter is input voltage,the rating is -0.3 to VDD+0.3,the unit is V;(4):the parameter is power dissipation,the rating is internally limited;(5):the parameter is ESD rating,the rating is 2000,200,500,the unit is V;(6):the parameter is junction temperature,the rating is 150,the unit is ;(7):the parameter is soldering information vapor phase (60 sec.),the rating is 215,the unit is ;(8):the parameter is soldering information infrared (15 sec.),the rating is 220,the unit is ;(9):the parameter is thermal resistance,the rating is 60,the unit is /W.