Features Improved click and pop circuitry virtually eliminates noise during turn on/off transitions DC Volume Control Interface System Beep Detect Stereo switchable bridged/single-ended power amplifiers Selectable internal/external gain and bass boost Thermal shutdown protection circuitry Unity gain stable Description The LM4938 is a monolithic integrated circuit that provides DC volume control, and stereo bridged audio power amplifiers capable of producing 2W into 4 with less than 1.0% THD or 2.2W into 3 with less than 1.0% THD. Boomer® audio integrated circuits were designed specifically to provide high quality audio while requiring a minimum amount of external components. The LM4938 incorporates a DC volume control, stereo bridged audio power amplifiers and a selectable gain or bass boost, making it optimally suited for multimedia monitors, portable radios, desktop, and portable computer applications. The LM4938 features an externally controlled, low-power consumption shutdown mode, and both a power amplifier and headphone mute for maximum system flexibility and performance. Key Specification PO at 1% THD+N   into 3 2.2W (typ) into 4 2.0W (typ) into 8 1.3W (typ) Single-ended mode - THD+N at 92mW into 32 1.0%(typ) Shutdown current 0.5µA (typ) Applications Flat Panel Displays Portable and Desktop Computers Multimedia Monitors Portable Radios, PDAs, and Portable TVs

Typical Application click for larger image	Block Diagram click for larger image
Typical Performance click for larger image

Datasheets

Title		Size	Date	Other Language
	LM4938 Stereo 2W Audio Power Amplifiers with DC Volume Control and Selectable Gain	1642 Kbytes	15-Jul-05

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM4938MH/NOPB LM4938MH RoHS Status	TSSOP EXP PAD	Full production Lead Time: 6 weeks	Distributor Region Qty DIGI-KEY Worldwide 44 FARNELL Europe and Asia 298	$0.92 each at 1K+ pcs	rail of 48
LM4938MHX/NOPB LM4938MHX RoHS Status	TSSOP EXP PAD	Full production Lead Time: 6 weeks	Distributor Region Qty AITG Asia Pacific 1001 DIGI-KEY Worldwide 0	$0.92 each at 1K+ pcs	reel of 2500

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 LM4938.

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 LM4938 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
LM4938MH/NOPB LM4938MH	117.59 118.211	TSSOP EXP PAD	28	1 1	260 260	Detail	Download	N/A	NSUZXYTTE# LM4938MH
LM4938MHX/NOPB LM4938MHX	117.59 118.211	TSSOP EXP PAD	28	1 1	260 260	Detail	Download	N/A	NSUZXYTTE# LM4938MH

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 LM4938.

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 LM4938 is located at RoHS Status.

CAD Symbols and Models Download LM4938 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4938MH	CMOS7	0	21301	0	0	1584000	3	449464325
LM4938MHX	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 LM4938.

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 LM4938 is located at RoHS Status.