Features No output filter required for inductive loads Externally configurable gain Very fast turn on time: 1.35ms (typ) Minimum external components "Click and pop" suppression circuitry Micro-power shutdown mode Short circuit protection Available in space-saving microSMD and LLP packages Description The LM4670 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 external component count, simplifies circuit design, and reduces board area. The LM4670 processes analog inputs with a delta-sigma modulation technique that lowers output noise and THD when compared to conventional pulse width modulators. The LM4670 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 4 speaker load at a continuous average output of 2.3W with less than 1% THD+N. Its flexible power supply requirements allow operation from 2.4V to 5.5V. The LM4670 has high efficiency with speaker loads compared to a typical Class AB amplifier. With a 3.6V supply driving an 8 speaker, the IC's efficiency for a 100mW power level is 77%, reaching 88% at 600mW output power. The LM4670 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 LM4670 is externally configurable which allows independent gain control from multiple sources by summing the signals. Key Specification Efficiency at 3.6V, 100mW into 8 speaker 77% (typ) Efficiency at 3.6V, 600mW into 8 speaker 88% (typ) Efficiency at 5V, 1W into 8 speaker 87% (typ) Quiescent current, 3.6V supply 4.8mA (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 *click for larger image
Typical Performance *click for larger image

Datasheets

Title		Size	Date	Other Language
	LM4670 Filterless High Efficiency 3W Switching Audio Amplifier	1191 Kbytes	13-Jul-06

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM4670ITL/NOPB RoHS Status	MICRO SMD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0 FARNELL Europe and Asia 890 RS COMPONENTS Worldwide 230	$0.52 each at 1K+ pcs	reel of 250
LM4670ITLX/NOPB RoHS Status	MICRO SMD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.52 each at 1K+ pcs	reel of 3000
LM4670SD/NOPB LM4670SD RoHS Status	LLP	Full production Lead Time: 10 weeks	Distributor Region Qty CEAC Asia Pacific 1000 DIGI-KEY Worldwide 0 FARNELL Europe and Asia 2061	$0.54 each at 1K+ pcs	reel of 1000
LM4670SDX/NOPB LM4670SDX RoHS Status	LLP	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 0	$0.54 each at 1K+ pcs	reel of 4500

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 LM4670.

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 LM4670 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
LM4670ITL/NOPB	2.784	MICRO SMD	9	1	260	Detail	Download	N/A	XVG I E6
LM4670ITLX/NOPB	2.784	MICRO SMD	9	1	260	Detail	Download	N/A	XVG I E6
LM4670SD/NOPB LM4670SD	20.736 20.803	LLP	8	1 1	260 260	Detail	Download	N/A	ZXYTT L4670
LM4670SDX/NOPB LM4670SDX	20.736 20.803	LLP	8	1 1	260 260	Detail	Download	N/A	ZXYTT L4670

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 LM4670.

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 LM4670 is located at RoHS Status.

CAD Symbols and Models Download LM4670 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4670ITL	CMOS7	0	21301	0	0	1584000	3	449464325
LM4670ITLX	CMOS7	0	21301	0	0	1584000	3	449464325
LM4670SD	CMOS7	0	21301	0	0	1584000	3	449464325
LM4670SDX	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 LM4670.

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 LM4670 is located at RoHS Status.