LM3875 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – OverturTM Audio Power Amplifier Series High-Performance 56W Audio Power Amplifier

August 2000
LM3875 Overture^™ Audio Power Amplifier Series
High-Performance 56W Audio Power Amplifier
General Description
The LM3875 is a high-performance audio power amplifier
capable of delivering 56W of continuous average power to
an 8Ω load with 0.1% THD+N from 20Hz to 20kHz.
The performance of the LM3875, utilizing its Self Peak In-
stantaneous Temperature (˚Ke) (SPiKe™) protection cir-
cuitry, puts it in a class above discrete and hybrid amplifiers
by providing an inherently, dynamically protected Safe Op-
erating Area (SOA). SPiKe protection means that these
parts are completely safeguarded at the output against ov-
ervoltage, undervoltage, overloads, caused by shorts to the
supplies, thermal runaway, and instantaneous temperature
peaks.
The LM3875 maintains an excellent signal-to-noise ratio of
greater than 95dB(min) with a typical low noise floor of
2.0µV. It exhibits extremely low THD+N values of 0.06% at
the rated output into the rated load over the audio spectrum,
and provides excellent linearity with an IMD (SMPTE) typical
rating of 0.004%.
Features
n 56W continuous average output power into 8Ω
n 100W instantaneous peak output power capability
n Signal-to-Noise Ratio >95dB (min)
n Output protection from a short to ground or to the
supplies via internal current limiting circuitry
n Output over-voltage protection against transients from
inductive loads
n Supply under-voltage protection, not allowing internal
biasing to occur when |V+| + |V−| ≤ 12V, thus eliminating
turn-on and turn-off transients
n 11 lead TO-220 package
n Wide supply voltage range: |V+| + |V−| = 20V to 84V
Applications
n Component or compact stereos
n Self-powered speakers
n Surround-sound amplifiers
n High-end stereo TVs
Typical Application
01144901
*Optional components dependent upon specific design requirements. Refer to the External Components Description section for a component function
description.
FIGURE 1. Typical Audio Amplifier Application Circuit
Overture™ and SPiKe™ are trademarks of National Semiconductor Corporation.
© 2004 National Semiconductor Corporation DS011449
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