LM49450 - I2S Input, 2.5W/Channel, Low EMI, Stereo, Class D Audio Sub-System with Ground Referenced Headphone Amplifier, 3D Enhancement, and Headphone Sense
Datasheet Packaging Samples & Pricing Reliability Knowledge Base

Features
•24–Bit Stereo DAC
•Stereo Filterless Class D Operation
•Selectable spread spectrum mode reduces EMI
•Ground Referenced Headphone Amplifiers with 100dB SNR
•I 2S Compatible Audio Interface
•Audio Sample Rates up to 192kHz
•National’s 3D Enhancement
•32-step Digital Volume Control
•I 2C Compatible Control Interface
•Headphone Sense Input
•Stereo Analog Line Inputs
•Output Short Circuit Protection
•Thermal Overload Protection
•Minimum external components
•Click and Pop suppression
•Micro-power shutdown
•Available in space-saving 32 pin LLP package

Key Specification

■  SNR at Headphone Output 102dBA (typ)
■  Speaker Amplifier Efficiency  at 3.6V, 650mW/channel into 8Ω 87% (typ)
■  Speaker Amplifier Efficiency  at 5V, 1.1W/channel into 8Ω 80% (typ)
■  Quiescent Power Supply Current   Line Inputs:
 Speaker Mode at LSVDD = 3.6V 7.5mA (typ)
 Headphone Mode at HPVDD = 2.5V 5.3mA (typ)
■  Output Power/Channel  
 Speaker at LSVDD = 5V:  
 RL = 4Ω, THD+N ≤ 10% 2.5W (typ)
 RL = 8Ω, THD+N ≤ 1% 1.25W (typ)
 Headphone at HPVDD = 2.5V:  
 RL = 16Ω, THD+N ≤ 1% 34mW (typ)
 RL = 32Ω, THD+N ≤ 1% 36mW (typ)
■  PSRR at 1kHz  Speaker Mode  Headphone Mode 67dB ( typ) 77dB (typ)
■  Shutdown current 0.02μA (typ)

General Description

The LM49450 is a fully integrated audio subsystem designed for portable media player applications. More...


Applications

•Portable Media Players
•Portable Navigation Devices
•Multi-Media Monitors
•Laptops
•Portable Gaming Devices
•Mobile Handsets
  Typical Application
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ParametersValues
Power@ 4Ohms, 10% THD 2.5 Watt
Power@ 4Ohms, 1% THD 1.9 Watt
Power@ 8Ohms, 10% THD 1.54 Watt
Power@ 8Ohms, 1% THD 1.25 Watt
THD 0.06 %
SNR 92 dB
Channels 2 Channels
THD Conditions Vdd= 3.6V, Po=300mW
SNR Conditions Vdd=3.6V, Po=500mW, f=1kHz, A-weighted
Interface I2S
Stereo Inputs Single Ended
National 3D Yes
Supply Range +2.7 - +5.5 V
Temperature Min -40 deg C
Temperature Max 85 deg C
Loudspeaker Type Class D
Headphone Type True Ground
Automotive Yes
Loudspeaker Outputs 2
D/A Channels 2


Typical Performance

*click for larger image


  Connection Diagram
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Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM49450  I 2 S Input, 2.5W/Channel, Low EMI, Stereo, Class D Audio Sub-System with Ground Referenced Headphone Amplifier, 3D Enhancement, and Headphone Sense 1131
Kbytes		 26-Sep-08 Download

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Package Availability, Models, Samples & Pricing
Part NumberPackageFactory Lead TimeModelsSamples &
Electronic
Orders		Budgetary PricingStd
Pack
Size		Package
Marking
Format
TypePinsSpec.MSL
Rating		Peak
Reflow		RoHS
Report		CAD
Symbols		WeeksQtyQty$US each
LM49450SQLLP32NOPB1260RoHS N/A Full productionN/A
Samples
Buy Now 		1K+$3.20reel
of
1000		NS
UZXYTT
L49450
12 weeksN/A
LM49450SQXLLP32NOPB1260RoHS N/A Full productionN/A
 
Buy Now 		1K+$3.20reel
of
4500		NS
UZXYTT
L49450
12 weeksN/A

General Description

The LM49450 is a fully integrated audio subsystem designed for portable media player applications. The LM49450 combines a 24-bit I 2S digital-to-analog converter (DAC), 2.5W/channel stereo Class D speaker drivers, 36mW stereo ground referenced headphone drivers, volume control, and National’s unique 3D sound enhancement into a single device.

The filterless Class D amplifiers deliver 1.25W/channel into an 8Ω load with <1% THD+N with a 5V supply. The LM49450 offers two logic selectable modulation schemes, fixed frequency mode, and an EMI reducing spread spectrum mode. The 36mW/channel headphone drivers feature National’s ground referenced architecture that creates a ground-referenced output from a single supply, eliminating the need for bulky and expensive DC-blocking capacitors, saving space and minimizing system cost. A headphone sense input (HPS) automatically detects the presence of a headphone, and configures the device accordingly.

The LM49450 stereo, 24-bit DAC supports a wide range of sample rates (including 192kHz, 96kHz, 48kHz, and 44.1kHz). The digital audio signal path features better than 100dB SNR, and low 0.05% THD+N when measured at the headphone outputs. The flexible 3-wire I 2S interface supports left or right justified audio data.

The LM49450 features separate 32-step volume control for the headphones and speaker outputs. 3D enhancement, mode selection, shutdown control, and volume are controlled through an I 2C compatible interface.

Output short circuit and thermal overload protection prevent the device from being damaged during fault conditions. Superior click and pop suppression eliminates audible transients on power-up/down and during shutdown. The LM49450 is available in a space saving 32-pin LLP package.

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM49450SQCMOS70184060010890004309006723
LM49450SQXCMOS70184060010890004309006723

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.


[Information as of 7-Nov-2009]