LM4651 Datasheet, PDF (1/20 Pages) National Semiconductor (TI) – LM4651 & LM4652 Overture™ Audio Power Amplifier 170W Class D Audio Power Amplifier Solution

August 2000
LM4651 & LM4652 Overture^™ Audio Power Amplifier
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
voltage, over modulation, and thermal shut down protection
circuitry. It contains a standby function, which shuts down
the pulse width modulation and minimizes supply current.
The LM4652 is a fully integrated H-bridge power MOSFET
IC in a TO-220 power package. Together, these two IC’s
form a simple, compact high power audio amplifier 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 in-
creases the efficiency compared to Class AB amplifiers. This
high efficiency solution significantly reduces the heat sink
size compared 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
n Output power into 4Ω with < 10% THD. 170W (Typ)
n THD at 10W, 4Ω, 10 − 500Hz.
< 0.3% THD (Typ)
n Maximum efficiency at 125W
n Standby attenuation.
85% (Typ)
>100dB (Min)
Features
n Conventional pulse width modulation.
n Externally controllable switching frequency.
n 50kHZ to 200kHz switching frequency range.
n Integrated error amp and feedback amp.
n Turn−on soft start and under voltage lockout.
n Over modulation protection (soft clipping).
n Short circuit current limiting and thermal shutdown
protection.
n 15 Lead TO−220 isolated package.
n Self checking protection diagnostic.
Applications
n Powered subwoofers for home theater and PC’s
n Car booster amplifier
n Self-powered speakers
Connection Diagrams
LM4651 Plastic Package
LM4652 Plastic Package (Note 8)
DS101277-72
Top View
Order Number LM4651N
See NS Package Number N28B
Overture^® is a registered trademark of National Semiconductor Corporation.
© 2001 National Semiconductor Corporation DS101277
DS101277-73
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
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