IC AMP AUDIO PWR 1.5W MONO 24LLP

LM4851LQ/NOPB

Manufacturer Part NumberLM4851LQ/NOPB
DescriptionIC AMP AUDIO PWR 1.5W MONO 24LLP
ManufacturerNational Semiconductor
SeriesBoomer®
TypeClass AB
LM4851LQ/NOPB datasheet
 


Specifications of LM4851LQ/NOPB

Output Type1-Channel (Mono) with Stereo HeadphonesMax Output Power X Channels @ Load1.5W x 1 @ 4 Ohms; 115mW x 2 @ 32 Ohms
Voltage - Supply2.6 V ~ 5 VFeaturesDepop, Shutdown, SPI, Thermal Protection, Volume Control
Mounting TypeSurface MountPackage / Case24-LLP
Lead Free Status / RoHS StatusLead free / RoHS CompliantOther names*LM4851LQ
LM4851LQ
LM4851LQNOPB
LM4851LQNOPBTR
LM4851LQNOPBTR
LM4851LQTR
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LM4851
Integrated Audio Amplifier System
General Description
The LM4851 is an audio power amplifier system capable of
delivering 1.1W (typ) of continuous average power into a
mono 8Ω bridged-tied load (BTL) with 1% THD+N and
115mW (typ) per channel of continuous average power into
stereo 32Ω BTL loads with 0.5% THD+N, using a 5V power
supply.
The LM4851 features a 32 step digital volume control and
eight distinct output modes. The digital volume control and
output modes are programmed through a three-wire SPI
serial control interface, that allows flexibility in routing and
mixing audio channels. The LM4851 has 3 inputs: one pair
for a two-channel stereo signal and the third for a single-
channel mono input.
The LM4851 is designed for cellular phone, PDA, and other
portable handheld applications. It delivers high quality output
power from a surface-mount package and requires only five
external components.
The industry leading micro SMD package utilizes only 2mm
x 2.3mm of PCB space, making the LM4851 the most space
efficient audio sub system available today.
Typical Application
FIGURE 1. Typical Audio Amplifier Application Circuit
Boomer
®
is a registered trademark of National Semiconductor Corporation.
© 2002 National Semiconductor Corporation
Key Specifications
n THD+N at 1kHz, 1.5W into 4Ω BTL (LQ)
n THD+N at 1kHz, 1.1W into 8Ω BTL
n THD+N at 1kHz, 115mW into 32Ω BTL
n Single Supply Operation
Features
n Mono 1.1W (typ) and stereo 115mW (typ) output
n SPI programmable 32 step digital volume control
(-40.5dB to +6dB)
n Eight distinct SPI programmable output modes
n micro-SMD and LLP surface mount packaging
n “Click and pop” suppression circuitry
n Thermal shutdown protection
n Low shutdown current (0.1µA, typ)
Applications
n Mobile phones
n PDAs
DS200408
December 2002
1% (typ)
1% (typ)
0.5% (typ)
2.6 to 5.0V
20040831
www.national.com

LM4851LQ/NOPB Summary of contents

  • Page 1

    ... Typical Application FIGURE 1. Typical Audio Amplifier Application Circuit Boomer ® registered trademark of National Semiconductor Corporation. © 2002 National Semiconductor Corporation Key Specifications n THD+N at 1kHz, 1.5W into 4Ω BTL (LQ) n THD+N at 1kHz, 1.1W into 8Ω BTL n THD+N at 1kHz, 115mW into 32Ω ...

  • Page 2

    Connection Diagrams 18-Bump micro SMD Marking (IBL) Top View XY- Date Code TT - Die Traceability G - Boomer Family 52 - LM4851IBL CONNECT Top View (Bump-side down) Order Number LM4851ITL, LM4851IBL See NS Package Number TLA18AAA, ...

  • Page 3

    ... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage Storage Temperature ESD Susceptibility (Note 4) ESD Machine model (Note 7) Junction Temperature ( Solder Information (Note 1) Vapor Phase (60 sec.) Infrared (15 sec.) ...

  • Page 4

    Electrical Characteristics The following specifications apply for V Symbol Parameter Digital Volume Range ( Digital Volume Stepsize Stepsize Error Phone In Volume Phone In Volume Phone In Input Impedance R and Enable ...

  • Page 5

    Electrical Characteristics The following specifications apply for V Symbol Parameter Total Harmonic Distortion Plus THD+N Noise N Output Noise OUT PSRR Power Supply Rejection Ratio V Logic High Input Voltage IH V Logic Low Input Voltage IL Digital Volume Range ...

  • Page 6

    Note 7: Machine Model ESD test is covered by specification EIAJ IC-121-1981. A 200pF cap is charged to the specified voltage, then discharged directly into the IC with no external series resistor (resistance of discharge path must be under 50Ω). ...

  • Page 7

    Typical Performance Characteristics THD+N vs Frequency THD+N vs Frequency THD+N vs Output Power (LM4851LQ) (Continued) THD+N vs Frequency 20040865 THD+N vs Frequency 20040867 THD+N vs Output Power (LM4851LQ) 200408B6 7 20040866 20040868 200408B7 www.national.com ...

  • Page 8

    Typical Performance Characteristics THD+N vs Output Power THD+N vs Output Power THD+N vs Output Power www.national.com (Continued) THD+N vs Output Power 20040839 THD+N vs Output Power 20040841 THD+N vs Output Power 20040843 8 20040840 20040842 20040844 ...

  • Page 9

    Typical Performance Characteristics Power Supply Rejection Ratio Power Supply Rejection Ratio Power Supply Rejection Ratio (Continued) Power Supply Rejection Ratio 20040845 Power Supply Rejection Ratio 20040860 Power Supply Rejection Ratio 20040862 9 20040874 20040861 20040859 www.national.com ...

  • Page 10

    Typical Performance Characteristics Output Power vs Supply Voltage Output Power vs Supply Voltage Output Power vs Load Resistance www.national.com (Continued) Output Power vs Supply Voltage 20040846 vs Load Resistance 20040848 Power Dissipation vs Output Power 20040869 10 20040847 Output Power ...

  • Page 11

    Typical Performance Characteristics Power Dissipation vs Output Power Channel Separation vs Frequency Frequency Response (Continued) vs Supply Voltage 20040872 Frequency Response 200408A6 Frequency Response 200408A9 11 Supply Current 20040855 200408A8 200408B0 www.national.com ...

  • Page 12

    Typical Performance Characteristics Output Noise vs Output Mode ( volume control gain X = Not applicable www.national.com (Continued) Frequency Response = 3V, 5V; A-weighted) DD Output Mode SPKROUT LOUT/ROUT Output Noise Output Noise (µ ...

  • Page 13

    Application Information SPI PIN DESCRIPTION DATA: This is the serial data input pin. CLK: This is the clock input pin. ENB: This is the SPI enable pin and is active-high. SPI OPERATION DESCRIPTION The serial data bits are organized into ...

  • Page 14

    Application Information Gain (dB) Data 7 -40.5 0 -39.0 0 -37.5 0 -36.0 0 -34.5 0 -33.0 0 -31.5 0 -30.0 0 -28.5 0 -27.0 0 -25.5 0 -24.0 0 -22.5 0 -21.0 0 -19.5 0 -18.0 0 -16.5 1 ...

  • Page 15

    ... LM4851’s thermal shutdown protection. Further detailed and specific information con- cerning PCB layout and fabrication and mounting an LQ (LLP) is found in National Semiconductor’s AN1187. PCB LAYOUT AND SUPPLY REGULATION CONSIDERATIONS FOR DRIVING 3Ω AND 4Ω LOADS Power dissipated by a load is a function of the voltage swing across the load and the load’ ...

  • Page 16

    Application Information as load impedance decreases. Therefore, to maintain the highest load dissipation and widest output voltage swing, PCB traces that connect the output pins to a load must be as wide as possible. Poor power supply regulation adversely affects ...

  • Page 17

    Application Information power, higher ambient temperatures are allowed as output power or duty cycle decreases. If the result of Equation (5) is greater than that of Equation (6), then decrease the supply voltage, increase the load impedance, or reduce the ...

  • Page 18

    Demonstration Board Layout FIGURE 3. Recommended IBL, ITL PC Board Layout: Top Silkscreen FIGURE 4. Recommended IBL, ITL PC Board Layout: Inner Layer www.national.com 200408A1 FIGURE 5. Recommended IBL, ITL PC Board Layout: 200408A2 FIGURE 6. Recommended IBL, ITL PC ...

  • Page 19

    Demonstration Board Layout (Continued) FIGURE 7. Recommended LQ PC Board Layout: Top Silkscreen Layer FIGURE 8. Recommended LQ PC Board Layout: Top Layer FIGURE 9. Recommended LQ PC Board Layout: 200408B8 FIGURE 10. Recommended LQ PC Board Layout: 200408B9 FIGURE ...

  • Page 20

    Physical Dimensions www.national.com inches (millimeters) unless otherwise noted 18-Bump micro SMD Order Number LM4851IBL NS Package Number BLA18AAB X = 1.996 X = 2.225 X = 0.945 ...

  • Page 21

    Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 18-Bump micro SMD Order Number LM4851ITL NS Package Number TLA18AAA X = 1.996 X = 2.225 X = 0.600 www.national.com ...

  • Page 22

    ... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...