LM4734 Datasheet, PDF (1/24 Pages) National Semiconductor (TI) – 3 Channel 20W Audio Power Amplifier with Mute and Standby

February 2004
LM4734
3 Channel 20W Audio Power Amplifier with Mute and
Standby
General Description
The LM4734 is a three channel audio amplifier capable of
typically delivering 20W per channel of continuous average
output power into a 4Ω or 8Ω load with less than 10%
THD+N from 20Hz - 20kHz.
The LM4734 has short circuit protection and a thermal shut
down feature that is activated when the die temperature
exceeds 150˚C. The LM4734 also has an under voltage lock
out feature for click and pop free power on and off.
Each amplifier of the LM4734 has an independent smooth
transition fade-in/out mute and a power conserving standby
mode. The mute and standby modes can be controlled by
external logic.
The LM4734 has a wide supply operating supply range from
±10V - ±30V allowing for lower cost unregulated power
supplies to be used.
The LM4734 can easily be configured for bridge or parallel
operation for higher power and bi-amp solutions.
Key Specifications
j Output Power/Channel with 10% THD+N,
1kHz into 4Ω or 8Ω
20W (typ)
j THD+N at 3x1W into 8Ω, 1kHz
0.03% (typ)
j Mute Attenuation
110dB (typ)
j PSRR
64dB (typ)
j Slew Rate
18V/µs (typ)
Features
n Low external component count
n Quiet fade-in/out mute mode
n Low power standby mode
n Wide supply range: 20V - 60V
Applications
n Audio amplifier for component stereo
n Audio amplifier for compact stereo
n Audio amplifier for home theater in a box (HTB)
n Audio amplifier for high-end and HD TVs
Typical Application
200898D2
FIGURE 1. Typical Audio Amplifier Application Circuit
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