Datasheet

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

LM4910

www.ti.com

SNAS151G –MAY 2004–REVISED MARCH 2007

LM4910 Output Capacitor-less Stereo 35mW Headphone

Amplifier

Check for Samples: LM4910

FEATURES

• Available in space-saving MSOP, LLP, and

SOIC packages

• Eliminates headphone amplifier output

coupling capacitors

APPLICATIONS

• Eliminates half-supply bypass capacitor

• Mobile Phones

• Advanced pop & click circuitry eliminates

• PDAs

noises during turn-on and turn-off

• Portable electronics devices

• Ultra-low current shutdown mode

• Portable MP3 players

• Unity-gain stable

• 2.2V - 5.5V operation

DESCRIPTION

The LM4910 is an audio power amplifier primarily designed for headphone applications in portable device

applications. It is capable of delivering 35mW of continuous average power to a 32Ω load with less than 1%

distortion (THD+N) from a 3.3V

power supply.

The LM4910 utilizes a new circuit topology that eliminates output coupling capacitors and half-supply bypass

capacitors. The LM4910 contains advanced pop & click circuitry which eliminates noises caused by transients

that would otherwise occur during turn-on and turn-off.

Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal

amount of external components. Since the LM4910 does not require any output coupling capacitors, half-supply

bypass capacitors, or bootstrap capacitors, it is ideally suited for low-power portable applications where minimal

space and power consumption are primary requirements.

The LM4910 features a low-power consumption shutdown mode, activated by driving the shutdown pin with logic

low. Additionally, the LM4910 features an internal thermal shutdown protection mechanism. The LM4910 is also

unity-gain stable and can be configured by external gain-setting resistors.

Table 1. Key Specifications

VALUE UNIT

PSRR at f = 217Hz 65 dB (typ)

Power Output at V

= 3.3V, R

= 32Ω, and THD ≤ 1% 35 mW (typ)

Shutdown Current 0.1 µA (typ)

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 (29 pages)

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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 LM4910 Output Capacitor-less Stereo 35mW Headphone Amplifier Check for Samples: LM4910 FEATURES • 1 • 2 • • • • • Eliminates headphone amplifier output coupling capacitors Eliminates half-supply bypass capacitor Advanced pop & click circuitry eliminates noises during turn-on and turn-off Ultra-low current shutdown mode Unity-gain stable 2.2V - 5.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com Typical Application Figure 1. Typical Audio Amplifier Application Circuit Connection Diagram Figure 2. MSOP/SO Package Top View Figure 3. MSOP Marking Top View G - Boomer Family C2 - LM4910MM Figure 4.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 Figure 5. LLP Package Top View 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 Supply Voltage (1) (2) 6.0V −65°C to +150°C Storage Temperature Input Voltage Power Dissipation -0.3V to VDD + 0.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 Electrical Characteristics VDD = 3.3V www.ti.com (1) (2) The following specifications apply for VDD = 3.3V, AV = 1, and 32Ω load unless otherwise specified. Limits apply to TA = 25°C. Symbol Parameter Conditions LM4910 Typ (3) Limit Units (Limits) (4) (5) IDD Quiescent Power Supply Current VIN = 0V, 32Ω Load 3.5 6 mA (max) ISD Standby Current VSHUTDOWN = GND 0.1 1.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 Electrical Characteristics VDD = 3V (1) (2) The following specifications apply for VDD = 3V, AV = 1, and 32Ω load unless otherwise specified. Limits apply to TA = 25°C. Symbol Parameter Conditions LM4910 Typ (3) Limit Units (Limits) (4) (5) IDD Quiescent Power Supply Current VIN = 0V, 32Ω Load 3.3 6 mA (max) ISD Standby Current VSHUTDOWN = GND 0.1 1.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 Electrical Characteristics VDD = 2.6V www.ti.com (1) (2) The following specifications apply for VDD = 2.6V, AV = 1, and 32Ω load unless otherwise specified. Limits apply to TA = 25°C. Symbol Parameter Conditions LM4910 Typ (3) Limit Units (Limits) (4) (5) IDD Quiescent Power Supply Current VIN = 0V, 32Ω Load 3.0 mA (max) ISD Standby Current VSHUTDOWN = GND 0.
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LM4910 www.ti.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.
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LM4910 www.ti.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com Typical Performance Characteristics (continued) Open Loop Frequency Response Noise Floor Frequency Response vs Input Capacitor Size Supply Current vs Supply Voltage Application Information ELIMINATING OUTPUT COUPLING CAPACITORS Typical single-supply audio amplifiers that drive single-ended (SE) headphones use a coupling capacitor on each SE output.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 OUTPUT TRANSIENT ('CLICK AND POPS') ELIMINATED The LM4910 contains advanced circuitry that virtually eliminates output transients ('clicks and pops'). This circuitry prevents all traces of transients when the supply voltage is first applied or when the part resumes operation after coming out of shutdown mode.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com POWER SUPPLY BYPASSING As with any amplifier, proper supply bypassing is important for low noise performance and high power supply rejection. The capacitor location on the power supply pins should be as close to the device as possible. Typical applications employ a 3.3V regulator with 10µF tantalum or electrolytic capacitor and a ceramic bypass capacitor which aid in supply stability.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 USING EXTERNAL POWERED SPEAKERS The LM4910 is designed specifically for headphone operation. Often the headphone output of a device will be used to drive external powered speakers. The LM4910 has a differential output to eliminate the output coupling capacitors. The result is a headphone jack sleeve that is connected to VO3 instead of GND.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com 1/(2π*20kΩ*20Hz) = 0.397µF (7) Use a 0.39µF capacitor, the closest standard value. The high frequency pole is determined by the product of the desired frequency pole, fH, and the differential gain, AV. With an AV = 1 and fH = 100kHz, the resulting GBWP = 100kHz which is much smaller than the LM4910 GBWP of 11MHz.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 Figure 7. The PCDN042 provides additional ESD protection beyond the 10kV shown in the Absolute Maximum Ratings for the Vo3 output Figure 8. Output Noise vs RSERIES Figure 9. Figure 10. Output Power vs RSERIES Figure 11.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com HIGHER GAIN AUDIO AMPLIFIER The LM4910 is unity-gain stable and requires no external components besides gain-setting resistors, input coupling capacitors, and proper supply bypassing in the typical application. However, if a very large closed-loop differential gain is required, a feedback capacitor (Cf) may be needed as shown in Figure 11 to bandwidth limit the amplifier.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 LM4910 SO DEMO BOARD ARTWORK Figure 12. Composite View Figure 13.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com Figure 14. Top Layer Figure 15.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 LM4910 MSOP DEMO BOARD ARTWORK Figure 16. Composite View Figure 17.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com Figure 18. Top Layer Figure 19.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 LM4910 LLP DEMO BOARD ARTWORK Figure 20. Composite View Figure 21.
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LM4910 SNAS151G – MAY 2004 – REVISED MARCH 2007 www.ti.com Figure 22. Top Layer Figure 23. Bottom Layer LM4910 Reference Design Boards Bill of Materials Part Description Qty LM4910 Mono Reference Design Board 1 Ref Designator LM4910 Audio AMP 1 U1 Tantalum Cap 1µF 16V 10 1 Cs Ceramic Cap 0.39µF 50V Z50 20 2 Ci Resistor 20kΩ 1/10W 5 4 Ri, Rf Resistor 100kΩ 1/10W 5 1 Rpu Jumper Header Vertical Mount 2X1, 0.
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LM4910 www.ti.com SNAS151G – MAY 2004 – REVISED MARCH 2007 Minimization of THD PCB trace impedance on the power, ground, and all output traces should be minimized to achieve optimal THD performance. Therefore, use PCB traces that are as wide as possible for these connections. As the gain of the amplifier is increased, the trace impedance will have an ever increasing adverse affect on THD performance.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE MATERIALS INFORMATION www.ti.com 12-Aug-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 LM4910LQ/NOPB WQFN NGP 8 1000 178.0 12.4 2.2 2.2 1.0 8.0 12.0 Q1 LM4910MM/NOPB VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 12-Aug-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM4910LQ/NOPB WQFN NGP 8 1000 213.0 191.0 55.0 LM4910MM/NOPB VSSOP DGK 8 1000 210.0 185.0 35.
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MECHANICAL DATA NGP0008A LQB08A (Rev B) www.ti.
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