Features 16-bit resolution stereo DAC I 2S digital audio data serial interface SPI serial interface (control register) Volume Control (32 steps; 1.5 dB increments) Up to 50mW/channel stereo headphone amplifier Zero Crossing Detection for Silent Attenuation Steps 2.6VDC to 5.0VDC digital supply voltage range 2.6VDC to 5.5VDC analog supply voltage range (Note 8) Unity-gain stable headphone amplifiers Available in the 20-bump microSMD package Description The LM4921 combines a 16-bit resolution stereo I 2S input digital-to-analog converter (DAC) with a stereo headphone audio power amplifier. It is primarily designed for demanding applications in mobile phones and other portable communication device applications. The LM4921 features an I 2S serial interface for the digital audio information and a 16-bit SPI serial interface for internal register control and communication. With AVDD and DVDD = 3.0VDC and driving a 32Ω single-ended load to a 26mWRMS output level the distortion (THD+N) of the LM4921 will be less than 0.5%. The LM4921 also features a programmable 32-step digital volume control accessed through an SPI interface. Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components. It is, therefore, ideally suited for mobile phone and other low voltage applications where minimal power consumption is a primary requirement. The LM4921 features a low-power consumption shutdown mode, and also has an internal thermal shutdown protection mechanism. Key Specification ■   PSRR at 217Hz, A/DVDD = 3V, (Fig. 1) 52dB (typ) ■   POUT at AVDD = 3.0V, 32Ω      < 0.05% THD 13mW (typ)    < 0.5% THD 26mW (typ) ■   Supply voltage range      DVDD 2.6V to 5.0V    AVDD (Note 8) 2.6V to 5.5V ■   Shutdown current 1µA (typ) 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
	LM4921 Low Voltage IS 16-Bit Stereo DAC with Stereo Headphone Power Amplifiers and Volume Control	457 Kbytes	30-May-07

Part Number(s) (NSID)	Top View	Availability	Current Reported Stock	Budgetary Pricing	Pack Size
LM4921ITL/NOPB RoHS Status	MICRO SMD	Full production Lead Time: 6 weeks	Distributor Region Qty ARROW Worldwide 500 DIGI-KEY Worldwide 647 MOUSER Worldwide 900 TAYLOR Americas 500	$1.03 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 LM4921.

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 LM4921 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
LM4921ITL/NOPB	6.926	MICRO SMD	20	1	260	Detail	Download	N/A	XYVG I B9

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 LM4921.

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 LM4921 is located at RoHS Status.

Design Tools

Title	Size	Date
Audio Amplifier Digital Control Interface Evaluation Board Software

CAD Symbols and Models Download LM4921 CAD Symbols

Models N/A

Reliability Metrics

Part Number	Process	EFR Reject	EFR Sample Size	PPM	LTA Rejects	LTA Device Hours	FITS	MTTF (Hours)
LM4921ITL	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 LM4921.

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 LM4921 is located at RoHS Status.