Features • No output filter required for inductive transducers • Selectable gain of 6dB (2V/V) or 12dB (4V/V) • Very fast turn on time: 5ms (typ) • User selectable shutdown High or Low logic level • Minimum external components • "Click and pop" suppression circuitry • Micro-power shutdown mode • Short circuit protection • micro SMD, LLP, and MSOP packages (no heat sink required) Description The LM4665 is a fully integrated single-supply high efficiency switching audio amplifier. It features an innovative modulator that eliminates the LC output filter used with typical switching amplifiers. Eliminating the output filter reduces parts count, simplifies circuit design, and reduces board area. The LM4665 processes analog inputs with a delta-sigma modulation technique that lowers output noise and THD when compared to conventional pulse width modulators. The LM4665 is designed to meet the demands of mobile phones and other portable communication devices. Operating on a single 3V supply, it is capable of driving 8 transducer loads at a continuous average output of 400mW with less than 2%THD+N. The LM4665 has high efficiency with an 8 transducer load compared to a typical Class AB amplifier. With a 3V supply, the IC's efficiency for a 100mW power level is 75%, reaching 80% at 400mW output power. The LM4665 features a low-power consumption shutdown mode. Shutdown may be enabled by either a logic high or low depending on the mode selection. Connecting the Shutdown Mode pin to either VDD (high) or GND (low) enables the Shutdown pin to be driven in a likewise manner to activate shutdown. The LM4665 has fixed selectable gain of either 6dB or 12dB. The LM4665 has short circuit protection against a short from the outputs to VDD, GND or across the outputs. Key Specification Efficiency at 100mW into 8 transducer 75%(typ) Efficiency at 400mW into 8 transducer 80%(typ) Total quiescent power supply current (3V) 3mA(typ) Total shutdown power supply current (3V) 0.01µA(typ) Single supply range (MSOP & LD) 2.7V to 5.5V Single supply range (ITL) (Note 11) 2.7V to 3.8V Applications • Mobile phones • PDAs • Portable electronic devices

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Datasheet

Title		Size	Date	Other Language
	LM4665 Boomer ® Audio Power Amplifier Series Filterless High Efficiency 1W Switching Audio Amplifier	1018 Kbytes	20-Dec-02	日本語

Featured Application Notes

Title		Size	Date	Other Language
	AN-1651: Application Note 1651 Keeping Up with the Expanding Demands of High-Performance Audio	206 Kbytes	10-Jul-07	中文
	AN-1671: Application Note 1671 Gain and Linearity Testing for Precision Operational Amplifiers	417 Kbytes	21-May-08	日本語
	AN-1784: Application Note 1784 LMV1022 / LMV1023 Digital Output PDM Microphone Amplifier Demo Board User's Guide	3786 Kbytes	6-Mar-08

More Application Notes

Title		Size	Date	Other Language
	AN-1784: Application Note 1784 LMV1022 / LMV1023 Digital Output PDM Microphone Amplifier Demo Board User's Guide	3786 Kbytes	6-Mar-08
	AN-1671: Application Note 1671 Gain and Linearity Testing for Precision Operational Amplifiers	417 Kbytes	21-May-08	日本語
	AN-1651: Application Note 1651 Keeping Up with the Expanding Demands of High-Performance Audio	206 Kbytes	10-Jul-07	中文

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Standard Pack Size
LM4665LD/NOPB RoHS	LLP	Lifetime buy Lead Time: 16 weeks	Distributor Region Qty DIGIKEY Worldwide 0	$1.09 each at 1K+ pcs	reel of 1000
LM4665ITL/NOPB RoHS	MICRO SMD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGIKEY Worldwide 718 FARNELL Europe and Asia 49 RS COMPONENTS Worldwide 250	$1.02 each at 1K+ pcs	reel of 250

Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM4665IBLBD	LM4671ITLBD	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665ITLX	LM4671ITLX	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665LD	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM4665LDX	LM4673SDX	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665MM	LM4675SD	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM4665MMBD	LM4671ITLBD	NATIONAL SEMICONDUCTOR	16 Nov 2008

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4665ITL	CMOS7	0	18406	0	0	1089000	4	309006723
LM4665LD	CMOS7	0	18406	0	0	1089000	4	309006723

Note: The Early Failure Rates (EFR) were calculated as point estimate PPM based on rejects and sample size for EFR. The Long Term Failure Rates were calculated at 60% confidence using the Arrhenius equation at 0.7eV activation energy and derating the assumed stress temperature of 150°C to an application temperature of 55°C.

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Obsolete Versions

Obsolete Part	Alternate Part or Supplier	Source	Last Time Buy Date
LM4665IBLBD	LM4671ITLBD	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665ITLX	LM4671ITLX	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665LD	NONE	NATIONAL SEMICONDUCTOR	01 Dec 2009
LM4665LDX	LM4673SDX	NATIONAL SEMICONDUCTOR	16 Nov 2008
LM4665MM	LM4675SD	NATIONAL SEMICONDUCTOR	05 Mar 2008
LM4665MMBD	LM4671ITLBD	NATIONAL SEMICONDUCTOR	16 Nov 2008