Datasheet

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LM4862

www.ti.com

SNAS102F –MAY 1997–REVISED MAY 2013

LM4862 675 mW Audio Power Amplifier with Shutdown

Mode

Check for Samples: LM4862

FEATURES

DESCRIPTION

The LM4862 is a bridge-connected audio power

• No Output Coupling Capacitors, Bootstrap

amplifier capable of delivering typically 675mW of

Capacitors or Snubber Circuits are Necessary

continuous average power to an 8Ω load with 1%

• Small Outline or PDIP Packaging

THD+N from a 5V power supply.

• Unity-Gain Stable

Boomer audio power amplifiers were designed

• External Gain Configuration Capability

specifically to provide high quality output power with a

minimal amount of external components. Since the

• Pin Compatible with LM4861

LM4862 does not require output coupling capacitors,

bootstrap capacitors, or snubber networks, it is

APPLICATIONS

optimally suited for low-power portable systems.

• Portable Computers

The LM4862 features an externally controlled, low-

• Cellular Phones

power consumption shutdown mode, as well as an

• Toys and Games

internal thermal shutdown protection mechanism.

The unity-gain stable LM4862 can be configured by

KEY SPECIFICATIONS

external gain-setting resistors.

• THD+N for 500mW Continuous Average

Output Power at 1kHz into 8Ω 1% (max)

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

825 mW (typ)

• Shutdown Current 0.7μA (typ)

Typical Application

Connection Diagram

*Refer to Application Information for information concerning proper

selection of the input coupling capacitor.

Figure 1. Typical Audio Amplifier Application Figure 2. Small Outline and PDIP Package-Top

Circuit View

See Package Number D0008A or P0008E

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 (18 pages)

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LM4862 www.ti.com SNAS102F – MAY 1997 – REVISED MAY 2013 LM4862 675 mW Audio Power Amplifier with Shutdown Mode Check for Samples: LM4862 FEATURES DESCRIPTION • The LM4862 is a bridge-connected audio power amplifier capable of delivering typically 675mW of continuous average power to an 8Ω load with 1% THD+N from a 5V power supply.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com 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. 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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LM4862 www.ti.com SNAS102F – MAY 1997 – REVISED MAY 2013 Electrical Characteristics (1) (2) The following specifications apply for VDD = 5V unless otherwise specified. Limits apply for TA = 25°C. Symbol Parameter Conditions LM4862 Typical VDD Supply Voltage (3) Limit (4) Units (Limits) 2.7 V (min) 5.5 V (max) 6.0 mA (max) IDD Quiescent Power Supply Current VIN = 0V, IO = 0A (5) 3.6 ISD Shutdown Current VPIN1 = VDD 0.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com External Components Description (Figure 1) 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/(2πRiCI). 2. Ci Input coupling capacitor which blocks the DC voltage at the amplifier's input terminals. Also creates a highpass filter with Ri at fc = 1/(2πRiCi).
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LM4862 www.ti.com SNAS102F – MAY 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 Output Power Figure 6. Figure 7. THD+N vs Output Power THD+N vs Output Power Figure 8. Figure 9.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 6 Output Power vs Supply Voltage Output Power vs Supply Voltage Figure 10. Figure 11. Output Power vs Supply Voltage Output Power vs Load Resistance Figure 12. Figure 13. Power Dissipation vs Output Power Power Derating Curve Figure 14. Figure 15.
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LM4862 www.ti.com SNAS102F – MAY 1997 – REVISED MAY 2013 Typical Performance Characteristics (continued) Dropout Voltage vs Power Supply Noise Floor Figure 16. Figure 17. Frequency Response vs Input Capacitor Size Power Supply Rejection Ratio Figure 18. Figure 19. Open Loop Frequency Response Supply Current vs Supply Voltage Figure 20. Figure 21.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com APPLICATION INFORMATION BRIDGE CONFIGURATION EXPLANATION As shown in Figure 1, the LM4862 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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LM4862 www.ti.com SNAS102F – MAY 1997 – REVISED MAY 2013 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 Typical Performance Characteristics, the effect of a larger half supply bypass capacitor is improved PSSR due to increased half-supply stability.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com The LM4862 is unity-gain stable which gives a designer maximum system flexibility. The LM4862 should be used in low gain configurations to minimize THD+N values, and maximize 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.
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LM4862 www.ti.com SNAS102F – MAY 1997 – REVISED MAY 2013 From Equation 5, the minimum AVD is 2; use AVD = 2. Since the desired input impedance was 20 kΩ, and with a AVD of 2, a ratio of 1:1 of Rf to Ri results in an allocation of Ri = Rf = 20 kΩ. The final design step is to address the bandwidth requirements which must be stated as a pair of −3 dB frequency points. Five times away from a –3 dB point is 0.17 dB down from passband response which is better than the required ±0.25 dB specified.
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LM4862 SNAS102F – MAY 1997 – REVISED MAY 2013 www.ti.com REVISION HISTORY Changes from Revision E (May 2013) to Revision F • 12 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.com 18-Oct-2013 continues to take reasonable steps to provide representative and accurate information but may not have conducted destructive testing or chemical analysis on incoming materials and chemicals. TI and TI suppliers consider certain information to be proprietary, and thus CAS numbers and other limited information may not be available for release.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-May-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM4862MX/NOPB Package Package Pins Type Drawing SOIC D 8 SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 2500 330.0 12.4 Pack Materials-Page 1 6.5 B0 (mm) K0 (mm) P1 (mm) 5.4 2.0 8.0 W Pin1 (mm) Quadrant 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) LM4862MX/NOPB SOIC D 8 2500 367.0 367.0 35.
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