Datasheet

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LM4861

www.ti.com

SNAS095C –MAY 1997–REVISED MAY 2013

LM4861 1.1W Audio Power Amplifier with Shutdown Mode

Check for Samples: LM4861

FEATURES

DESCRIPTION

The LM4861 is a bridge-connected audio power

• No output coupling capacitors, bootstrap

amplifier capable of delivering 1.1W of continuous

capacitors, or snubber circuits are necessary

average power to an 8Ω load with 1% THD+N using

• Small Outline (SOIC) packaging

a 5V power supply.

• Compatible with PC power supplies

Boomer audio power amplifiers were designed

• Thermal shutdown protection circuitry

specifically to provide high quality output power with a

minimal amount of external components using

• Unity-gain stable

surface mount packaging. Since the LM4861 does

• External gain configuration capability

not require output coupling capacitors, bootstrap

capacitors, or snubber networks, it is optimally suited

APPLICATIONS

for low-power portable systems.

• Personal computers

The LM4861 features an externally controlled, low-

• Portable consumer products

power consumption shutdown mode, as well as an

internal thermal shutdown protection mechanism.

• Self-powered speakers

• Toys and games

The unity-gain stable LM4861 can be configured by

external gain-setting resistors for differential gains of

up to 10 without the use of external compensation

KEY SPECIFICATIONS

components. Higher gains may be achieved with

• THD+N for 1kHz at 1W continuous average

suitable compensation.

output power into 8Ω 1.0% (max)

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

1.5 W (typ)

• Shutdown Current 0.6µA (typ)

Connection Diagram

Figure 1. 8-Lead SOIC - Top View

See D Package

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.

2All 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 (20 pages)

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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 LM4861 1.1W Audio Power Amplifier with Shutdown Mode Check for Samples: LM4861 FEATURES DESCRIPTION • The LM4861 is a bridge-connected audio power amplifier capable of delivering 1.1W of continuous average power to an 8Ω load with 1% THD+N using a 5V power supply.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com Typical Application Figure 2. Typical Audio Amplifier Application Circuit These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 Absolute Maximum Ratings (1) (2) Supply Voltage 6.0V −65°C to +150°C Storage Temperature −0.3V to VDD + 0.3V Input Voltage Power Dissipation (3) Internally limited ESD Susceptibility (4) 3000V ESD Susceptibility (5) 250V Junction Temperature 150°C Soldering Information (1) (2) (3) (4) (5) SOIC Package Vapor Phase (60 sec.) 215°C Infrared (15 sec.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com High Gain Application Circuit Figure 3. Audio Ampiifier with AVD = 20 Single Ended Application Circuit *CS and CB size depend on specific application requirements and constraints. Typical vaiues of CS and CB are 0.1 μF. **Pin 1 should be connected to VDD to disable the amplifier or to GND to enable the amplifier. This pin should not be left floating. ***These components create a “dummy” load for pin 8 for stability purposes. Figure 4.
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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 External Components Description (Figure 2 and Figure 3) Components Functional Description 1. Ri Inverting input resistance which sets the closed-loop gain in conjunction with Rf. This resistor also forms a high pass filter with Ci at fC = 1 / (2π Ri Ci). 2. Ci Input coupling capacitor which blocks DC voltage at the amplifier's input terminals. Also creates a high pass filter with Ri at fC = 1 / (2π Ri Ci). 3.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics 6 THD+N vs Frequency THD+N vs Frequency Figure 5. Figure 6. THD+N vs Frequency THD+N vs Output Power Figure 7. Figure 8. THD+N vs Output Power Output Power vs Load Resistance Figure 9. Figure 10.
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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 Typical Performance Characteristics (continued) Output Power vs Supply Voltage Power Dissipation vs Output Power Figure 11. Figure 12. Noise Floor vs Frequency Supply Current Distribution vs Temperature Figure 13. Figure 14. Supply Current vs Supply Voltage Power Derating Curve Figure 15. Figure 16.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 8 Power Supply Rejection Ratio Open Loop Frequency Response Figure 17. Figure 18.
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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 APPLICATION INFORMATION BRIDGE CONFIGURATION EXPLANATION As shown in Figure 2 , the LM4861 has two operational amplifiers internally, allowing for a few different amplifier configurations. The first amplifier's gain is externally configurable, while the second amplifier is internally fixed in a unity-gain, inverting configuration.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com POWER SUPPLY BYPASSING As with any power amplifier, proper supply bypassing is critical for low noise performance and high power supply rejection. The capacitor location on both the bypass and power supply pins should be as close to the device as possible. As displayed in the Typical Performance Characteristics, the effect of a larger half supply bypass capacitor is improved low frequency THD+N due to increased half-supply stability.
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LM4861 www.ti.com SNAS095C – MAY 1997 – REVISED MAY 2013 AUDIO POWER AMPLIFIER DESIGN Design a 1W / 8Ω Audio Amplifier Given: Power Output 1 Wrms Load Impedance 8Ω Input Level 1 Vrms Input Impedance 20 kΩ Bandwidth 100 Hz–20 kHz ± 0.25 dB A designer must first determine the needed supply rail to obtain the specified output power. By extrapolating from Figure 11 in Typical Performance Characteristics, the supply rail can be easily found.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com LM4861 MDA MWA 1.1W Audio Power Amplifier with Shutdown Mode Figure 19. Die Layout (B - Step) Table 1. DIE/WAFER CHARACTERISTICS Fabrication Attributes Physical Die Identification Die Step General Die Information LM4861B Bond Pad Opening Size (min) 83µm x 83µm B Bond Pad Metalization ALUMINUM Passivation VOM NITRIDE Physical Attributes Wafer Diameter 150mm Back Side Metal BARE BACK Dise Size (Drawn) 1372µm x 2032µm 54.0mils x 80.
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LM4861 www.ti.
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LM4861 SNAS095C – MAY 1997 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision B (May 2013) to Revision C • 14 Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-May-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LM4861MX SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.0 Q1 LM4861MX/NOPB SOIC D 8 2500 330.0 12.4 6.5 5.4 2.0 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-May-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM4861MX SOIC D 8 2500 367.0 367.0 35.0 LM4861MX/NOPB SOIC D 8 2500 367.0 367.0 35.
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