Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) or 2-channel (stereo) Class AB TO 263 9

LM4950

www.ti.com

SNAS174E –JULY 2003–REVISED MAY 2013

LM4950 Boomer ™ Audio Power Amplifier Series 7.5W Mono-BTL or 3.1W Stereo Audio

Power Amplifier

Check for Samples: LM4950

FEATURES

DESCRIPTION

The LM4950 is a dual audio power amplifier primarily

• Pop & Click Circuitry Eliminates Noise During

designed for demanding applications in flat panel

Turn-On and Turn-Off Transitions

monitors and TV's. It is capable of delivering 3.1

• Low Current, Active-Low Shutdown Mode

watts per channel to a 4Ω single-ended load with less

• Low Quiescent Current

than 1% THD+N or 7.5 watts mono BTL to an 8Ω

load, with less than 10% THD+N from a 12V

power

• Stereo 3.1W Output, R

= 4Ω

supply.

• Mono 7.5W BTL Output, R

= 8Ω

Boomer audio power amplifiers were designed

• Short Circuit Protection

specifically to provide high quality output power with a

• Unity-Gain Stable

minimal amount of external components. The

• External Gain Configuration Capability

LM4950 does not require bootstrap capacitors or

snubber circuits. Therefore, it is ideally suited for

display applications requiring high power and minimal

KEY SPECIFICATIONS

size.

• Quiescent Power Supply Current 16mA (typ)

The LM4950 features a low-power consumption

• P

OUT

(SE)

active-low shutdown mode. Additionally, the LM4950

– V

= 12V, R

= 4Ω, 1% THD+N: 3.1W (typ)

features an internal thermal shutdown protection

• P

OUT

(BTL) mechanism along with short circuit protection.

– V

= 12V, R

= 8Ω, 10% THD+N: 7.5W (typ)

The LM4950 contains advanced pop & click circuitry

that eliminates noises which would otherwise occur

• Shutdown Current 40μA (typ)

during turn-on and turn-off transitions.

APPLICATIONS

The LM4950 is a unity-gain stable and can be

configured by external gain-setting resistors.

• Flat Panel Monitors

• Flat Panel TVs

• Computer Sound Cards

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.

2 is a trademark of ~ Texas Instruments Incorporated.

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 (30 pages)

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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 LM4950 Boomer ™ Audio Power Amplifier Series 7.5W Mono-BTL or 3.1W Stereo Audio Power Amplifier Check for Samples: LM4950 FEATURES DESCRIPTION • The LM4950 is a dual audio power amplifier primarily designed for demanding applications in flat panel monitors and TV's. It is capable of delivering 3.1 watts per channel to a 4Ω single-ended load with less than 1% THD+N or 7.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com TYPICAL APPLICATION Figure 1.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Connection Diagrams VIN B BYPASS VOUT B VDD GND (TAB) GND VOUT A SHUTDOWN VIN A Figure 2. Plastic Package, DDPAK Top View See Package Number KTW0009A 9 V IN 8 BYPASS 7 VOUT B 6 V DD 5 GND (TAB) B 4 GND 3 VOUT A 2 SHUTDOWN 1 VIN A Figure 3. Plastic Package, TO-220 Top View See Package Number NEC0009A These devices have limited built-in ESD protection.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Electrical Characteristics VDD = 12V (1) (2) The following specifications apply for VDD = 12V, AV = 0dB (SE) or 6dB (BTL) unless otherwise specified. Limits apply for TA = 25°C.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Figure 4. Typical Stereo Single-Ended (SE) Audio Amplifier Application Circuit External Components Description See Figure 1. Components Functional Description 1. RIN This is the inverting input resistance that, along with RF, sets the closed-loop gain. Input resistance RIN and input capacitance CIN form a high pass filter. The filter's cutoff frequency is fc = 1/(2πRINCIN). 2. CIN This is the input coupling capacitor.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics 6 THD+N vs Frequency THD+N vs Frequency Figure 5. VDD = 12V, RL = 8Ω BTL operation, POUT = 1W Figure 6. VDD = 12V, RL = 8Ω BTL operation, POUT = 3W THD+N vs Frequency THD+N vs Frequency Figure 7. VDD = 12V, RL = 8Ω BTL operation, POUT = 5W Figure 8. VDD = 12V, RL = 8Ω BTL operation, BTLAV = 20, POUT = 1W THD+N vs Frequency THD+N vs Frequency Figure 9.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Typical Performance Characteristics (continued) THD+N vs Frequency THD+N vs Frequency Figure 11. VDD = 12V, RL = 4Ω, SE operation, both channels driven and loaded (average shown), POUT = 1W, AV = 1 Figure 12. VDD = 12V, RL = 4Ω, SE operation, both channels driven and loaded (average shown), POUT = 2.5W, AV = 1 THD+N vs Frequency THD+N vs Output Power Figure 13.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 8 THD+N vs Output Power THD+N vs Output Power Figure 17. VDD = 12V, RL = 4Ω, SE operation, both channels driven and loaded (average shown), fIN = 1kHz Figure 18. VDD = 12V, RL = 8Ω, SE operation, both channels driven and loaded (average shown), fIN = 1kHz THD+N vs Output Power THD+N vs Output Power Figure 19.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Typical Performance Characteristics (continued) Output Power vs Power Supply Voltage Output Power vs Power Supply Voltage Figure 23. RL = 4Ω, SE operation, both channels driven and loaded (average shown), at (from top to bottom at 12V): THD+N = 10%, THD+N = 1% Figure 24.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 10 Total Power Dissipation vs Load Dissipation Total Power Dissipation vs Load Dissipation Figure 29. VDD = 12V, BTL operation, fIN = 1kHz, at (from top to bottom at 3W): RL = 8Ω, RL = 16Ω Figure 30. VDD = 12V, SE operation, fIN = 1kHz, at (from top to bottom at 1W): RL = 4Ω, RL = 8Ω Output Power vs Load Resistance Output Power vs Load Resistance Figure 31.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Typical Performance Characteristics (continued) THD+N vs Output Power THD+N vs Output Power Figure 35. VDD = 9.6V, RL = 8Ω, BTL operation, fIN = 1kHz Figure 36. VDD = 9.6V, RL = 4Ω, SE operation, fIN = 1kHz both channels driven and loaded (average shown) THD+N vs Output Power THD+N vs Output Power Figure 37. VDD = 9.6V, RL = 8Ω, BTL operation, BTLAV = 20, fIN = 1kHz Figure 38. VDD = 9.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 12 Output Power vs Load Resistance Output Power vs Load Resistance Figure 41. VDD = 9.6V, BTL operation, fIN = 1kHz, at (from top to bottom at 15Ω): THD+N = 10%, THD+N = 1% Figure 42. VDD = 9.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Typical Performance Characteristics (continued) THD+N vs Output Power Total Power Dissipation vs Load Dissipation Figure 47. VDD = 15V, RL = 8Ω, SE operation, fIN = 1kHz both channels driven and loaded (average shown) Figure 48. VDD = 15V, BTL operation, fIN = 1kHz, at (from top to bottom at 4W): RL = 8Ω, RL = 16Ω Total Power Dissipation vs Load Dissipation per Channel Output Power vs Load Resistance Figure 49.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 14 THD+N vs Output Power THD+N vs Output Power Figure 53. VDD = 16V, RL = 8Ω, BTL operation, fIN = 1kHz, BTLAV = 20 Figure 54. VDD = 16V, RL = 4Ω, AV = 10 SE operation, fIN = 1kHz, both channels driven and loaded (average shown) Channel-to-Channel Crosstalk vs Frequency Channel-to-Channel Crosstalk vs Frequency Figure 55.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Typical Performance Characteristics (continued) Clipping Voltage vs Power Supply Voltage Clipping Voltage vs Power Supply Voltage Figure 59. RL = 8Ω, BTL operation, fIN = 1kHz at (from top to bottom at 12V): positive signal swing, negative signal swing Figure 60.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com APPLICATION INFORMATION HIGH VOLTAGE BOOMER WITH INCREASED OUTPUT POWER Unlike previous 5V Boomer amplifiers, the LM4950 is designed to operate over a power supply voltages range of 9.6V to 16V. Operating on a 12V power supply, the LM4950 will deliver 7.5W into an 8Ω BTL load with no more than 10% THD+N. Figure 65.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 POWER DISSIPATION Power dissipation is a major concern when designing a successful single-ended or bridged amplifier. Equation 2 states the maximum power dissipation point for a single-ended amplifier operating at a given supply voltage and driving a specified output load. PDMAX-SE = (VDD) 2/ (2π2RL): Single Ended (2) The LM4950's dissipation is twice the value given by Equation 2 when driving two SE loads.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com the BYPASS pin and ground improves the internal bias voltage's stability and improves the amplifier's PSRR. The PSRR improvements increase as the bypass pin capacitor value increases. Too large, however, increases turn-on time and can compromise the amplifier's click and pop performance.
PAGE 19
LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 The gain of the internal amplifiers remains unity until the voltage on the bypass pin reaches VDD/2. As soon as the voltage on the bypass pin is stable, the device becomes fully operational and the amplifier outputs are reconnected to their respective output pins. Although the BYPASS pin current cannot be modified, changing the size of CBYPASS alters the device's turn-on time.
PAGE 20
LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Figure 66. Piezo-electric Transducer Capacitance ≤ 200nF AUDIO POWER AMPLIFIER DESIGN Audio Amplifier Design: Driving 4W into an 8Ω BTL The following are the desired operational parameters: Power Output 4WRMS Load Impedance 8Ω Input Level 0.3VRMS (max) Input Impedance 20kΩ Bandwidth 50Hz–20kHz ± 0.25dB The design begins by specifying the minimum supply voltage necessary to obtain the specified output power.
PAGE 21
LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 The Output Power vs. Power Supply Voltage graph in Typical Performance Characteristics for an 8Ω load indicates a minimum supply voltage of 10.2V. The commonly used 12V supply voltage easily meets this. The additional voltage creates the benefit of headroom, allowing the LM4950 to produce peak output power in excess of 4W without clipping or other audible distortion.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Demonstration Board Layout Figure 67. Recommended KTW SE PCB Layout: Top Silkscreen Figure 68.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 Figure 69. Recommended KTW SE PCB Layout: Bottom Layer Figure 70.
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LM4950 SNAS174E – JULY 2003 – REVISED MAY 2013 www.ti.com Figure 71. Recommended KTW BTL PCB Layout: Top Layer Figure 72.
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LM4950 www.ti.com SNAS174E – JULY 2003 – REVISED MAY 2013 REVISION HISTORY Changes from Revision D (May 2013) to Revision E • Page Changed layout of National Data Sheet to TI format ..........................................................................................................
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Nov-2013 TAPE AND REEL INFORMATION *All dimensions are nominal Device LM4950TSX/NOPB Package Package Pins Type Drawing SPQ DDPAK/ TO-263 500 KTW 9 Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) 330.0 24.4 Pack Materials-Page 1 10.75 B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant 14.85 5.0 16.0 24.
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PACKAGE MATERIALS INFORMATION www.ti.com 8-Nov-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM4950TSX/NOPB DDPAK/TO-263 KTW 9 500 367.0 367.0 45.
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MECHANICAL DATA KTW0009A TS9A (Rev B) BOTTOM SIDE OF PACKAGE www.ti.
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