LM4651_09 Datasheet, PDF (1/32 Pages) National Semiconductor (TI) – 170W Class D Audio Power Amplifier Solution

LM4651 & LM4652
Overture™ Audio Power
Amplifier
OBSOLETE
July 9, 2009
170W Class D Audio Power Amplifier Solution
General Description
The IC combination of the LM4651 driver and the LM4652
power MOSFET provides a high efficiency, Class D sub-
woofer amplifier solution.
The LM4651 is a fully integrated conventional pulse width
modulator driver IC. The IC contains short circuit, under volt-
age, over modulation, and thermal shut down protection cir-
cuitry. The LM4651also contains a standby function which
shuts down the pulse width modulation minimizing supply
current. The LM4652 is a fully integrated H-bridge power
MOSFET IC in a TO-220 power package. The LM4652 has a
temperature sensor built in to alert the LM4651 when the die
temperature of the LM4652 exceeds the threshold. Together,
these two IC's form a simple, compact high power audio am-
plifier solution complete with protection normally seen only in
Class AB amplifiers. Few external components and minimal
traces between the IC's keep the PCB area small and aids in
EMI control.
The near rail-to-rail switching amplifier substantially increases
the efficiency compared to Class AB amplifiers. This high ef-
ficiency solution significantly reduces the heat sink size com-
pared to a Class AB IC of the same power level. This two-chip
solution is optimum for powered subwoofers and self powered
speakers.
Key Specifications
■ ^{Output power into 4Ω with < 10% THD.}
170W (Typ)
■ ^{THD at 10W, 4Ω, 10 − 500Hz.}
< 0.3% THD (Typ)
■ ^{Maximum efficiency at 125W}
85% (Typ)
■ ^{Standby attenuation.}
>100dB (Min)
Features
■ ^{Conventional pulse width modulation.}
■ ^{Externally controllable switching frequency.}
■ ^{50kHz to 200kHz switching frequency range.}
■ ^{Integrated error amp and feedback amp.}
■ ^{Turn−on soft start and under voltage lockout.}
■ ^{Over modulation protection (soft clipping).}
■ ^{Externally controllable output current limiting and thermal}
shutdown protection.
■ ^{Self checking protection diagnostic.}
Applications
■ ^{Powered subwoofers for home theater and PC's}
■ ^{Car booster amplifier}
■ ^{Self-powered speakers}
Connection Diagrams
LM4651 Plastic Package
LM4652 Plastic Package (Note 8)
Top View
10127772
Order Number LM4651N
See NS Package Number N28B
10127773
Isolated TO-220 Package
Order Number LM4652TF
See NS Package Number TF15B
or
Non-Isolated TO-220 Package
Order Number LM4652TA
See NS Package Number TA15A
Overture^® is a registered trademark of National Semiconductor.
© 2009 National Semiconductor Corporation 101277
101277 Version 9 Revision 2 Print Date/Time: 2009/07/09 16:41:57
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