LM48520 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – Boosted Stereo Class D Audio Power Amplifier with Output Speaker Protection and Spread Spectrum

LM48520, LM48520TLBD
www.ti.com
SNAS367C – FEBRUARY 2008 – REVISED APRIL 2013
LM48520
Boosted Stereo Class D Audio Power Amplifier
with Output Speaker Protection and Spread Spectrum
Check for Samples: LM48520, LM48520TLBD
FEATURES
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•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
KEY SPECIFICATIONS
• Quiescent Power Supply Current: 11.5 mA(typ)
• Output Power (R_L = 8Ω, THD+N ≤ 1%,
V_DD = 3.3V,PV1 = 5.0V): 1.1 W(typ)
• Shutdown Current: 0.04 μA(typ)
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.
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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.
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