LM48520_14 Datasheet, PDF (1/20 Pages) Texas Instruments – Boosted Stereo Class D Audio Power Amplifier with Output Speaker Protection and Spread Spectrum

LM48520, LM48520TLBD
www.ti.com
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
FEATURES
1
•2 Click and Pop Suppression
• Low 0.04μA Shutdown Current
• 78% Efficiency
• Filterless Class D
• 2.7V - 5.0V operation
• 4 Adjustable Gain settings
• Adjustable output swing limiter with Soft
Clipping
• Speaker Protection
• Short circuit protection on Audio Amps
• Independent Boost and Amplifier shutdown
pins
APPLICATIONS
• Mobile Phones
• PDAs
• Portable media
• Cameras
• Handheld games
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 8Ω 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.
■ Quiescent Power Supply Current
■ Output Power
(R_L = 8Ω, THD+N ≤ 1%,
V_DD = 3.3V,PV1 = 5.0V)
■ Shutdown Current
Table 1. Key Specifications
VALUE
11.5mA (typ)
1.1
0.04μA (typ)
UNIT
W (typ)
1
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
All trademarks are the property of their respective owners.
2
PRODUCTION DATA information is current as of publication date.
Products conform to specifications per the terms of the Texas
Instruments standard warranty. Production processing does not
necessarily include testing of all parameters.
Copyright © 2008, Texas Instruments Incorporated