Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier Headphones (2-channel, stereo) Class AB SOIC 8

LM4881

www.ti.com

SNAS001D –SEPTEMBER 1997–REVISED MAY 2013

LM4881 Dual 200 mW Headphone Amplifier with

Shutdown Mode

Check for Samples: LM4881

FEATURES

DESCRIPTION

The LM4881 is a dual audio power amplifier capable

• VSSOP Surface Mount Packaging

of delivering 200mW of continuous average power

• Unity-gain Stable

into an 8Ω load with 0.1% THD+N from a 5V power

• External Gain Configuration Capability

supply.

• Thermal Shutdown Protection Circuitry

Boomer™ audio power amplifiers were designed

• No Bootstrap Capacitors, or Snubber Circuits

specifically to provide high quality output power with a

minimal amount of external components using

are Necessary

surface mount packaging. Since the LM4881 does

not require bootstrap capacitors or snubber networks,

APPLICATIONS

it is optimally suited for low-power portable systems.

• Headphone Amplifier

The LM4881 features an externally controlled, low

• Personal Computers

power consumption shutdown mode which is virtually

• Microphone Preamplifier

clickless and popless, as well as an internal thermal

shutdown protection mechanism.

KEY SPECIFICATIONS

The unity-gain stable LM4881 can be configured by

• THD+N at 1kHz at 125mW Continuous Average

external gain-setting resistors.

Output Power into 8Ω 0.1% (max)

• THD+N at 1kHz at 75mW Continuous

0.02% (typ)

• Output Power at 10% THD+N at 1kHz into 8Ω

300 mW (typ)

• Shutdown Current 0.7µA (typ)

• Supply Voltage Range 2.7V to 5.5 V

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2Boomer is a trademark of Texas Instruments.

3All other trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (15 pages)

PAGE 1
LM4881 www.ti.com LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Dual 200 mW Headphone Amplifier with Shutdown Mode Check for Samples: LM4881 FEATURES DESCRIPTION • • • • • The LM4881 is a dual audio power amplifier capable of delivering 200mW of continuous average power into an 8Ω load with 0.1% THD+N from a 5V power supply.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com Typical Application *Refer to Application Information for information concerning proper selection of the input and output coupling capacitors. Figure 1. Typical Audio Amplifier Application Circuit Connection Diagrams Figure 2. VSSOP Package Top View See Package Number DGK0008A Figure 3. SOIC and PDIP Package Top View See Package Number D0008A, or P0008E These devices have limited built-in ESD protection.
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LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Absolute Maximum Ratings (1) (2) Supply Voltage 6.0V −65°C to +150°C Storage Temperature −0.3V to VDD + 0.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com Electrical Characteristics(1)(2) (continued) The following specifications apply for VDD = 5V unless otherwise specified. Limits apply for TA = 25C. Symbol Parameter Conditions LM4881 Typ PO Output Power (3) Limit (4) Units (Limits) THD = 0.1% (max); f = 1 kHz; RL = 8Ω 200 RL = 16Ω 150 125 mW (min) mW RL = 32Ω 85 mW RL = 8Ω 300 mW RL = 16Ω 200 mW RL = 32Ω 110 mW RL = 16Ω, P O = 120 mWrms; 0.
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LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Typical Performance Characteristics THD+N vs Frequency THD+N vs Frequency Figure 4. Figure 5. THD+N vs Frequency THD+N vs Frequency Figure 6. Figure 7. THD+N vs Frequency THD+N vs Frequency Figure 8. Figure 9.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 6 THD+N vs Output Power THD+N vs Output Power Figure 10. Figure 11. THD+N vs Output Power THD+N vs Output Power Figure 12. Figure 13. THD+N vs Output Power THD+N vs Output Power Figure 14. Figure 15.
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LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Typical Performance Characteristics (continued) Output Power vs Supply Voltage Output Power vs Supply Voltage Figure 16. Figure 17. Output Power vs Supply Voltage Power Dissipation vs Output Power Figure 18. Figure 19. Output Power vs Load Resistance Output Power vs Load Resistance Figure 20. Figure 21.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) Power Dissipation vs Output Power Clipping Voltage vs Supply Voltage Figure 22. Figure 23. Clipping Voltage vs Supply Voltage 8 Channel Separation Figure 24. Figure 25. Output Attenuation in Shutdown Mode Supply Current vs Supply Voltage Figure 26. Figure 27.
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LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Typical Performance Characteristics (continued) Power Supply Rejection Ratio Open Loop Frequency Response Figure 28. Figure 29. Noise Floor Frequency Response vs Output Capacitor Size Figure 30. Figure 31. Frequency Response vs Output Capacitor Size Frequency Response vs Output Capacitor Size Figure 32. Figure 33.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) Typical Application Frequency Response Typical Application Frequency Response Figure 34. Figure 35. Power Derating Curve Figure 36.
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LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 APPLICATION INFORMATION SHUTDOWN FUNCTION In order to reduce power consumption while not in use, the LM4881 contains a shutdown pin to externally turn off the amplifier's bias circuitry. This shutdown feature turns the amplifier off when a logic high is placed on the shutdown pin. The trigger point between a logic low and logic high level is typically half supply.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com The LM4881 is unity gain stable and this gives a designer maximum system flexibility. The LM4881 should be used in low gain configurations to minimize THD+N values, and maximum the signal-to-noise ratio. Low gain configurations require large input signals to obtain a given output power. Input signals equal to or greater than 1 Vrms are available from sources such as audio codecs.
PAGE 13
LM4881 www.ti.com SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 Once the power dissipation equations have been addressed, the required gain can be determined from Equation 4. (4) (5) AV = Rf/Ri From Equation 4, the minimum gain is: AV = 1.26 Since the desired input impedance was 20 kΩ, and with a gain of 1.26, a value of 27 kΩ is designated for Rf, assuming 5% tolerance resistors. This combination results in a nominal gain of 1.35.
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LM4881 SNAS001D – SEPTEMBER 1997 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision C (May 2013) to Revision D • 14 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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