Features No output filter required for inductive loads Externally configurable gain Very fast turn on time: 17μs (typ) Minimum external components "Click and pop" suppression circuitry Micro-power shutdown mode Available in space-saving microSMD package Description The LM4671 is a single supply, high efficiency 2.5W switching audio amplifier. A low noise, filterless PWM architecture eliminates the output filter, reducing external component count, board area consumption, system cost, and simplifying design. The LM4671 is designed to meet the demands of mobile phones and other portable communication devices. Operating on a single 5V supply, it is capable of driving a 4Ω speaker load at a continuous average output of 2.1W with less than 1% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The LM4671 has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3V supply driving an 8Ω speaker, the IC's efficiency for a 100mW power level is 80%, reaching 88% at 400mW output power. The LM4671 features a low-power consumption shutdown mode. Shutdown may be enabled by driving the Shutdown pin to a logic low (GND). The gain of the LM4671 is externally configurable which allows independent gain control from multiple sources by summing the signals. Key Specification ■  Efficiency @ 3.6V, 100mW into   8Ω speaker 80% (typ) ■  Efficiency @ 3.6V, 400mW into    8Ω speaker 88% (typ) ■  Efficiency @ 5V, 1W into 8Ω   speaker 86% (typ) ■  Quiescent current, 3.6V supply 2.8mA (typ) ■  Total shutdown power supply   current 0.01µA (typ) ■  Single supply range 2.4V to 5.5V Applications Mobile phones PDAs Portable electronic devices

Typical Application click for larger image	Connection Diagram click for larger image
Typical Performance *click for larger image

Datasheets

Title		Size	Date	Other Language
	LM4671 Filterless High Efficiency 2.5W Switching Audio Amplifier	589 Kbytes	3-Mar-08

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM4671ITL/NOPB RoHS Status	MICRO SMD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.44 each at 1K+ pcs	reel of 250

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM4671.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM4671 is located at RoHS Status.

Part Number(s) (NSID)	Weight (milligrams)	Type	Pins	MSL Rating	Peak Reflow	RoHS Status	CAD Symbols	Models	Package Marking Format
LM4671ITL/NOPB	2.916	MICRO SMD	9	1	260	Detail	Download	N/A	XVG I E7

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM4671.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM4671 is located at RoHS Status.

CAD Symbols and Models Download LM4671 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4671ITL	CMOS7	0	21301	0	0	1584000	3	449464325

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.

For more information on Reliability Metrics, please click here.

All information pertaining to the RoHS Compliance Standard can be found at http://www.national.com/en/packaging/leadfree.html.

Moisture Sensitivity Level Data for LM4671.

A RoHS compliance or an IPC 1752 report can be acquired at http://www.national.com/en/packaging/greennopb.html.

National's certificate of product compliance for LM4671 is located at RoHS Status.