OBSOLETE
LM4651, LM4652
www.ti.com
SNOS507G – MAY 2004 – REVISED JULY 2009
LM4651 & LM4652 Overture™ Audio Power Amplifier 170W Class D Audio Power
Amplifier Solution
Check for Samples: LM4651, LM4652
FEATURES
1
•
•
•
•
•
•
•
23
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
DESCRIPTION
The IC combination of the LM4651 driver and the LM4652 power MOSFET provides a high efficiency, Class D
subwoofer 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. 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 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 increases 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.
Table 1. Key Specifications
VALUE
UNIT
Output power into 4Ω with < 10% THD.
170
W (Typ)
THD at 10W, 4Ω, 10 − 500Hz.
< 0.3% THD
(Typ)
Maximum efficiency at 125W
85% (Typ)
Standby attenuation.
>100
dB (Min)
1
2
3
Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of
Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.
Overture is a trademark of dcl_owner.
All other trademarks are the property of their respective owners.
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.
Copyright © 2004–2009, Texas Instruments Incorporated