Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsLinear IC - Audio amplifier 1-channel (mono) Class AB VSSOP 8

8 7

3 4

GND

IN-

IN+

BYP

IN-

IN+

GND

BYP

LM4923, LM4923LQBD

www.ti.com

SNAS211E –JULY 2004–REVISED MAY 2013

LM4923 1.1 Watt Fully Differential Audio Power Amplifier

With Shutdown Select

Check for Samples: LM4923, LM4923LQBD

FEATURES

DESCRIPTION

The LM4923 is a fully differential audio power

• Fully Differential Amplification

amplifier primarily designed for demanding

• Available in Space-saving WQFN Package

applications in mobile phones and other portable

• Ultra Low Current Shutdown Mode

communication device applications. It is capable of

delivering 1.1 watt of continuous average power to an

• Can Drive Capacitive Loads up to 100pF

8Ω BTL load with less than 1% distortion (THD+N)

• Improved Pop & Click Circuitry Eliminates

from a 5V

power supply.

Noises During Turn-on and Turn-off

Boomer audio power amplifiers were designed

Transitions

specifically to provide high quality output power with a

• 2.4 - 5.5V Operation

minimal amount of external components. The

• No Output Coupling Capacitors, Snubber

LM4923 does not require output coupling capacitors

Networks or Bootstrap Capacitors Required

or bootstrap capacitors, and therefore is ideally suited

for mobile phone and other low voltage applications

where minimal power consumption is a primary

APPLICATIONS

requirement.

• Mobile Phones

The LM4923 features a low-power consumption

• PDAs

shutdown mode. To facilitate this, Shutdown may be

• Portable Electronic Devices

enabled by logic low. Additionally, the LM4923

features an internal thermal shutdown protection

KEY SPECIFICATIONS

mechanism.

• Improved PSRR at 217Hz 85dB(typ)

The LM4923 contains advanced pop & click circuitry

• Power Output at 5.0V @ 1% THD+N 1.1W(typ)

which eliminates noises which would otherwise occur

during turn-on and turn-off transitions.

• Power Output at 3.3V @ 1% THD+N

400mW(typ)

• Shutdown Current 0.1μA(typ)

Connection Diagrams

Figure 1. NGP Package, Top View Figure 2. 8 Pin VSSOP Package, Top View

See Package Number NGP0008A See Package Number DGK0008A

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 (22 pages)

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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 LM4923 1.1 Watt Fully Differential Audio Power Amplifier With Shutdown Select Check for Samples: LM4923, LM4923LQBD FEATURES DESCRIPTION • • • • • The LM4923 is a fully differential audio power amplifier primarily designed for demanding applications in mobile phones and other portable communication device applications. It is capable of delivering 1.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Typical Application VDD CS 1 PF RF1 20 k: R i1 20 k: + -IN - Differential Input + SD 1.0 PF + Differential Input Ri2 20 k: RF2 20 k: CB Bias VO+ RL Common Mode 8: - BYP VO- + +IN GND Figure 3. Typical Audio Amplifier Application Circuit These devices have limited built-in ESD protection.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 Operating Ratings Temperature Range TMIN ≤ TA ≤ TMAX −40°C ≤ TA ≤ 85°C 2.4V ≤ VDD ≤ 5.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Electrical Characteristics VDD = 5V (1) (2) The following specifications apply for VDD = 5V, AV = 1, and 8Ω load unless otherwise specified. Limits apply for TA = 25°C. Symbol Parameter LM4923 Conditions Typical (3) Limit (4) Units (Limits) IDD Quiescent Power Supply Current VIN = 0V, no load VIN = 0V, RL = 8Ω 4 4 9 9 mA (max) ISD Shutdown Current VSHUTDOWN = GND 0.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 Electrical Characteristics VDD = 3V (1) (2) The following specifications apply for VDD = 3V, AV = 1, and 8Ω load unless otherwise specified. Limits apply for TA = 25°C. Symbol Parameter Conditions LM4923 Typical (3) Limit (4) Units (Limits) IDD Quiescent Power Supply Current VIN = 0V, no load VIN = 0V, RL = 8Ω 3 3 5.5 5.5 mA (max) ISD Shutdown Current VSHUTDOWN = GND 0.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics THD+N vs Frequency VDD = 2.6V, RL = 4Ω, PO = 150mW 10 10 1 1 THD+N (%) THD+N (%) THD+N vs Frequency VDD = 2.6V, RL = 8Ω, PO = 150mW 0.1 0.1 0.01 0.01 0.001 20 100 1k 0.001 20 10k 20k 100 FREQUENCY (Hz) 10 Figure 5. THD+N vs Frequency VDD = 5V, RL = 8Ω, PO = 400mW THD+N vs Frequency VDD = 3V, RL = 8Ω, PO = 275mW 10 THD+N (%) THD+N (%) 1 0.1 0.1 0.01 0.01 0.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 Typical Performance Characteristics (continued) 10 THD+N vs Output Power VDD = 2.6V, RL = 4Ω 10 THD+N vs Output Power VDD = 5V, RL = 8Ω 20 kHz 1 1 THD+N (%) THD+N (%) 20 kHz 1 kHz 0.1 0.01 0.1 1 kHz 20 Hz 0.01 20 Hz 0.001 10m 100m 0.001 10m 1 100m OUTPUT POWER (W) Figure 10. Figure 11. THD+N vs Output Power VDD = 3V, RL = 8Ω THD+N vs Output Power VDD = 3V, RL = 4Ω THD+N (%) 1 1 kHz 1 kHz 0.1 0.01 20 Hz 0.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) 2 0 1.8 -10 1.6 -20 1.4 -30 CMRR (dB) OUTPUT POWER (W) Output Power vs Supply Voltage RL = 8Ω 1.2 10% THD+N 1 800m 1% THD+N CMRR vs Frequency VDD = 5V, RL = 8Ω -40 -50 -60 600m -70 400m -80 -90 200m 0 2.4 3 3.5 4.5 4 5 -100 20 5.5 100 Figure 17.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 Typical Performance Characteristics (continued) Power Dissipation vs Output Power VDD = 5V, RL = 8Ω 0.7 Power Dissipation vs Output Power VDD = 3V, RL = 8Ω 0.25 POWER DISSIPATION (W) POWER DISSIPATION (W) 0.6 0.5 0.4 0.3 0.2 0.2 0.15 0.1 0.05 0.1 0 0 0 0.2 0.4 0.8 0.6 1 1.2 1.4 0.1 0 OUTPUT POWER (W) Figure 22. OUTPUT NOISE VOLTAGE (V) POWER DISSIPATION (W) 0.6 0.5 0.4 0.3 0.2 0.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Typical Performance Characteristics (continued) Output Power vs Load Resistance 1.6 Supply Current Shutdown Voltage 5 5V, 10% THD+N 1.4 OUTPUT POWER (W) 1.0 3V, 10% THD+N 0.8 3V, 1% THD+N 0.6 0.4 2.6V, 10% THD+N 0.2 SUPPLY CURRENT (mA) 4 5V, 1% THD+N 1.2 3 2 1 0 2.6V, 1% THD+N 0 -1 4 8 12 16 20 24 28 32 0 LOAD RESISTANCE (:) Submit Documentation Feedback 1 1.5 2 2.5 SHUTDOWN VOLTAGE (V) Figure 28. 10 0.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 APPLICATION INFORMATION DIFFERENTIAL AMPLIFIER EXPLANATION The LM4923 is a fully differential audio amplifier that features differential input and output stages. Internally this is accomplished by two circuits: a differential amplifier and a common mode feedback amplifier that adjusts the output voltages so that the average value remains VDD / 2. When setting the differential gain, the amplifier can be considered to have "halves".
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Best thermal performance is achieved with the largest practical copper heat sink area. In all circumstances and conditions, the junction temperature must be held below 150°C to prevent activating the LM4923's thermal shutdown protection. Figure 24 in the Typical Performance Characteristics shows the maximum power dissipation versus temperature. Example PCB layouts are shown in the Demonstration Board Layout section.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – 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 ratio (PSRR). The capacitor location on both the bypass and power supply pins should be as close to the device as possible. A larger half-supply bypass capacitor improves PSRR because it increases half-supply stability. Typical applications employ a 5V regulator with 10µF and 0.
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LM4923, LM4923LQBD SNAS211E – JULY 2004 – REVISED MAY 2013 www.ti.com Tolerance RF1 RF2 V02 - V01 ILOAD 20% 0.8R 1.2R -0.500V 62.5mA 10% 0.9R 1.1R -0.250V 31.25mA 5% 0.95R 1.05R -0.125V 15.63mA 1% 0.99R 1.01R -0.025V 3.125mA 0% R R 0 0 Similar results would occur if the input resistors were not carefully matched.
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LM4923, LM4923LQBD www.ti.com SNAS211E – JULY 2004 – REVISED MAY 2013 Revision History Rev Date 1.0 09/28/07 Added the VSSOP package, then released. Description 1.01 12/17/07 Updated the mktg outline NGP0008A into the rev B. 1.02 02/19/09 Fixed typo labels on the typical circuit diagram. E 05/03/13 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 LM4923LQ/NOPB 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 WQFN NGP 8 1000 178.0 12.4 2.2 2.2 1.0 8.0 12.0 Q1 LM4923LQX/NOPB WQFN NGP 8 4500 330.0 12.4 2.2 2.2 1.0 8.0 12.0 Q1 LM4923MM/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 8-May-2013 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM4923LQ/NOPB WQFN NGP 8 1000 213.0 191.0 55.0 LM4923LQX/NOPB WQFN NGP 8 4500 367.0 367.0 35.0 LM4923MM/NOPB VSSOP DGK 8 1000 210.0 185.0 35.0 LM4923MMX/NOPB VSSOP DGK 8 3500 367.0 367.0 35.
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MECHANICAL DATA NGP0008A LQB08A (Rev B) www.ti.
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