LM4854 Datasheet, PDF(1/29 Page) National Semiconductor (TI) – 1.9W Monaural, 85mW Stereo Headphone Audio Amplifier

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LM4854 Datasheet, PDF (1/29 Pages) National Semiconductor (TI) – 1.9W Monaural, 85mW Stereo Headphone Audio Amplifier

April 2003

LM4854

1.9W Monaural, 85mW Stereo Headphone Audio

Amplifier

General 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. Oper-

ating on a single 5V supply, the mono BTL mode delivers

1.1W (typ) to an 8â¦ load, 1.7W (typ) to a 4â¦ load (Note 1) at

1% THD+N. In SE stereo mode, the amplifier will deliver

85mW to 32â¦ loads. The LM4854 features a new circuit

topology that suppresses output transients (âclick and popsâ)

and eliminates SE-mode output coupling capacitors, saving

both component 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, note-

book, 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, 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 applica-

tions, and TSSOP packages.

Note 1: An LM4854LD that has been properly mounted to a circuit board will

deliver 1.7W (typ) into a 4â¦ load.

Key Specifications

j LLP BTL output power (RL = 3.2â¦ and

THD+N = 1%)

VDD = 3.0V

VDD = 5.0V

j LLP BTL output power (RL = 4â¦ and

THD+N = 1%)

VDD = 3.0V

VDD = 5.0V

j LLP BTL output power (RL = 8â¦ and

THD+N = 1%)

VDD = 3.0V

VDD = 5.0V

1.0W (typ)

1.9W (typ)

900mW (typ)

1.7W (typ)

380mW (typ)

1.1W (typ)

j SE output power (RL = 32â¦ and THD+N

= 1.0%)

VDD = 3.0V

VDD = 5.0V

j Micropower shutdown supply current

32mW (typ)

93mW (typ)

VDD = 3.0V

VDD = 5.0V

j Standby supply current

0.005ÂµA (typ)

0.05ÂµA (typ)

VDD = 3.0V

VDD = 5.0V

j PSRR (f = 1kHz, 3.0V â¤ VDD â¤ 5.0V,

(Fig. 1))

16ÂµA (typ)

27ÂµA (typ)

BTL

60dB (typ)

66dB (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 Space-saving micro SMD package, exposed-DAP LLP,

and TSSOP

Applications

n PDAs

n Notebook computers

n Cellular phones

n Handheld portable electronic devices

BoomerÂ® is a registered trademark of National Semiconductor Corporation.

www.national.com

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