LM48520, LM48520TLBD

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SNAS367B – FEBRUARY 2008 – REVISED MARCH 2008

LM48520

Boosted Stereo Class D Audio Power Amplifier

with Output Speaker Protection and Spread Spectrum

Check for Samples: LM48520, LM48520TLBD

1

FEATURES

•

Independent Boost and Amplifier shutdown

pins

2

•

Click and Pop Suppression

•

Low 0.04

μA Shutdown Current

APPLICATIONS

•

78% Efficiency

•

Mobile Phones

•

Filterless Class D

•

PDAs

•

2.7V - 5.0V operation

•

Portable media

•

4 Adjustable Gain settings

•

Cameras

•

Adjustable output swing limiter with Soft

•

Handheld games

Clipping

•

Speaker Protection

•

Short circuit protection on Audio Amps

DESCRIPTION

The LM48520 integrates a boost converter with a high efficiency Class D stereo audio power amplifier to provide

up to 1W/ch continuous power into an 8

Ω speaker when operating from 2.7V to 5.0V power supply with boost

voltage (PV1) of 5.0V. The LM48520 utilizes a proprietary spread spectrum pulse width modulation technique

that lowers RF interference and EMI levels. The Class D amplifier is a low noise, filterless PWM architecture that

eliminates the output filter, reducing external component count, board area, power consumption, system cost,

and simplifying design.

The LM48520 is designed for use in mobile phones and other portable communication devices. The high (78%)

efficiency extends battery life when compared to Boosted Class AB amplifiers. The LM48520 features a low-

power consumption shutdown mode. Shutdown may be enabled by driving the Shutdown pin to a logic low

(GND). Also, external leakage is minimized via control of the ground reference via the SW-OUT pin .

The LM48520 has 4 gain options which are pin selectable via Gain0 and Gain1 pins. Output short circuit

prevents the device from damage during fault conditions. Superior click and pop suppression eliminates audible

transients during power-up and shutdown.

Table 1. Key Specifications

VALUE

UNIT

■ Quiescent Power Supply Current

11.5mA (typ)

■ Output Power

1.1

W (typ)

■ Shutdown Current

0.04

μA (typ)

1

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Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2

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PRODUCTION DATA information is current as of publication date.

Copyright © 2008, Texas Instruments Incorporated

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.