LM4941 - 1.25 Watt Fully Differential Audio Power Amplifier With RF Suppression and Shutdown from the PowerWise® Family

Datasheet Packaging Samples & Pricing Eval. Boards Reliability Application Notes Knowledge Base

Features
• Improved RF suppression, by up to 20dB over previous designs in selected applications
• Fully differential amplification
• Available in space-saving micro SMD package
• Ultra low current shutdown mode
• Can drive capacitive loads up to 100pF
• Improved pop & click circuitry eliminates noises during turn-on and turn-off transitions
• 2.4 - 5.5V operation
• No output coupling capacitors, snubber networks or bootstrap capacitors required

Key Specification

■  Improved PSRR at 217Hz 95dB (typ)
■  Power Output, VDD = 5.0V,  RL = 8Ω, 1% THD+N 1.25W (typ)
■  Power Output, VDD = 3.0V,  RL = 8Ω, 1% THD+N 430mW (typ)
■  Shutdown Current 0.1µA (typ)

General Description

The LM4941 is a fully differential audio power amplifier primarily designed for demanding applications in mobile phones and other portable communication device applications. More...


Applications

• Mobile phones
• PDAs
• Portable electronic devices
  Typical Application
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Parametric Table     expand
Parametric Table    collapse
Power@ 8Ohms, 1% THD 1.25 Watt
Power@ 8Ohms, 10% THD 1.54 Watt
THD 0.04 %
PSRR 95 dB
THD Conditions Pout = 700mW, f = 1kHz
PSRR Conditions Vripple = 200mVpp, f = 217Hz
Power@ 8Ohms, 1% THD 1.25 Watt
Power@ 8Ohms, 10% THD 1.54 Watt
THD 0.04 %
PSRR 95 dB
SNR 108 dB
CMRR 70 dB
Channels 1 Channels
THD Conditions Pout = 700mW, f = 1kHz
PSRR Conditions Vripple = 200mVpp, f = 217Hz
SNR Conditions Pout = 1W, f=1kHz
User Supply 5 Volt
Supply Range +2.4 - +5.5 V
Temperature Min -40 deg C
Temperature Max 85 deg C
Automotive Selection Guide Yes
PowerWise Yes
View Using Catalog


Typical Performance

click for larger image


  Additional Resources
Application Notes (see below)


Connection Diagram

click for larger image



Datasheet
RoHS Compliance Information Size in KbytesDate Click link below to Download
LM4941  1.25 Watt Fully Differential Audio Power Amplifier With RF Suppression and Shutdown 381 Kbytes 9-Mar-07 View Online
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
LM4941TMBD1.25 Watt Fully Differential Audio Power Amplifier With RF Suppression and ShutdownFull productionN/A
 
Buy Now 		1+$150.001-
N/AN/A
LM4941SDBDLM4941SD Evaluation BoardFull productionN/A
 
Buy Now 		1+$150.001-
N/AN/A
LM4941SDLLP8NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$0.66reel
of
1000		XYTT
4941
12 weeksN/A
LM4941TMMICRO SMD9NOPB1260RoHS Download Full productionN/A
Samples
Buy Now 		1K+$0.62reel
of
250		XVG
I H6
6 weeksN/A
LM4941TMXMICRO SMD9NOPB1260RoHS Download Full productionN/A
 
Buy Now 		1K+$0.62reel
of
3000		XVG
I H6
16 weeksN/A

General Description

The LM4941 is a fully differential audio power amplifier primarily designed for demanding applications in mobile phones and other portable communication device applications. It is capable of delivering 1.25 watts of continuous average power to a 8Ω load with less than 1% distortion (THD+N) from a 5VDC power supply. The LM4941 does not require output coupling capacitors or bootstrap capacitors, and therefore is ideally suited for mobile phone and other small form factor applications where minimal PCB space is a primary requirement.

The LM4941 also features proprietary internal circuitry that suppresses the coupling of RF signals into the chip. This is important because certain types of RF signals (such as GSM) can couple into audio amplifiers in such a way that part of the signal is heard through the speaker. The RF suppression circuitry in the LM4941 makes it well-suited for portable applications in which strong RF signals generated by an antenna from or a cellular phone or other portable electronic device may couple audibly into the amplifier.

Other features include a low-power consumption shutdown mode, internal thermal shutdown protection, and advanced pop & click circuitry.

Reliability Metrics

Part Number Process EFR Reject EFR Sample Size PPM * LTA Rejects LTA Device Hours FITS MTTF (Hours)
LM4941TMCMOS7013906008625005244736730
LM4941TMXCMOS7013906008625005244736730

Note: The Early Failure Rates were calculated as point estimates. 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.


More Application Notes

TitleSize in Kbytes Date Click link below to Download
AN-1567: Application Note 1567 LM4949 Demonstration Board 3533 Kbytes 18-Jul-07 Download
AN-1496: Application Note 1496 Noise, TDMA Noise, and Suppression Techniques 85 Kbytes 28-Apr-08 Download
AN-1496 (Chinese): Application Note 1496 Noise, TDMA Noise, and Suppression Techniques
 330 Kbytes  

If you have trouble printing or viewing PDF file(s), see Printing Problems.

[Information as of 13-Oct-2008]