LM4855ITLX

Manufacturer Part NumberLM4855ITLX
ManufacturerNational Semiconductor
LM4855ITLX datasheet
 


Specifications of LM4855ITLX

Operational ClassClass-ABAudio Amplifier Output Configuration1-Channel Mono/2-Channel Stereo
Audio Amplifier FunctionHeadphone/SpeakerTotal Harmonic Distortion0.5@8Ohm@400mW%
Single Supply Voltage (typ)3VDual Supply Voltage (typ)Not RequiredV
Supply Current (max)12@5VmAPower Supply RequirementSingle
Rail/rail I/o TypeNoPower Supply Rejection Ratio62dB
Single Supply Voltage (min)2.6VSingle Supply Voltage (max)5V
Dual Supply Voltage (min)Not RequiredVDual Supply Voltage (max)Not RequiredV
Operating Temp Range-40C to 85COperating Temperature ClassificationIndustrial
MountingSurface MountPin Count18
Package TypeuSMDLead Free Status / Rohs StatusNot Compliant
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LM4855
Integrated Audio Amplifier System
General Description
The LM4855 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 LM4855 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 LM4855 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 six
external components.
The industry leading micro SMD package only utilizes 2mm
x 2.3mm of PCB space, making the LM4855 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, 1.1W into 8Ω BTL
n THD+N at 1kHz, 115mW into 32Ω BTL
n Single Supply Operation
Features
n 1.1W (typ) output power with 8Ω mono BTL load
n 115mW (typ) output power with stereo 32Ω BTL loads
n SPI programmable 32 step digital volume control
n Eight distinct output modes
n micro-SMD and LLP surface mount packaging
n "Click and Pop" suppression circuitry
n Thermal shutdown protection
n Low shutdown current (0.1uA, typ)
Applications
n Moblie Phones
n PDAs
DS200395
November 2002
1.0% (typ)
0.5% (typ)
2.6 to 5.0V
200395D1
www.national.com

LM4855ITLX 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, 1.1W into 8Ω BTL n THD+N at 1kHz, 115mW into 32Ω BTL n Single Supply Operation Features n 1.1W (typ) output power with 8Ω ...

  • Page 2

    Connection Diagrams 18-Bump micro SMD Marking (IBL) Top View XY- Date Code TT - Die Traceability G - Boomer Family 55 - LM4855IBL LLP Package Top View Order Number LM4855LQ See NS Package Number LQA24A for Exposed-DAP LLP www.national.com 18-Bump ...

  • 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 PSRR Power Supply Rejection Ratio SPKR OUT Power Supply Rejection Ratio R and L OUT OUT V Logic High Input Voltage IH V Logic Low Input Voltage IL Digital Volume ...

  • Page 5

    Electrical Characteristics The following specifications apply for V Symbol Parameter I Supply Current DD I Shutdown Current SD V Output Offset Voltage OS P Output Power O Total Harmonic Distortion Plus THD+N Noise N Output Noise OUT Power Supply Rejection ...

  • Page 6

    Electrical Characteristics The following specifications apply for V Symbol Parameter Digital Volume Range ( Digital Volume Stepsize Digital Volume Stepsize Error Phone_In_IHF Volume Phone _In_IHF Mute Attenuation Phone_In_IHF Input Impedance Phone_In_HS Input Impedance R and L ...

  • Page 7

    External Components Description Components 1. C This is the input coupling capacitor. It blocks the DC voltage and couples the input signal to the amplifier’s IN input terminals 1/(2π This is the ...

  • Page 8

    Typical Performance Characteristics THD+N vs Frequency THD+N vs Frequency THD+N vs Frequency www.national.com (Continued) THD+N vs Frequency 200395B3 THD+N vs Frequency 200395B5 THD+N vs Frequency 200395B7 8 200395B4 200395B6 200395B8 ...

  • Page 9

    Typical Performance Characteristics THD+N vs Output Power LM4855LQ THD+N vs Output Power THD+N vs Output Power (Continued) THD+N vs Output Power 200395F2 THD+N vs Output Power 200395B9 THD+N vs Output Power 200395C1 9 LM4855LQ 200395F3 200395C0 200395C2 www.national.com ...

  • Page 10

    Typical Performance Characteristics Power Supply Rejection Ratio Power Supply Rejection Ratio Power Supply Rejection Ratio www.national.com (Continued) Power Supply Rejection Ratio 200395C3 Power Supply Rejection Ratio 200395C5 Power Supply Rejection Ratio 200395C7 10 200395C4 200395C6 200395C8 ...

  • Page 11

    Typical Performance Characteristics Output Power vs Supply Voltage Output Power vs Load Resistance Power Dissipation vs Output Power (Continued) Output Power vs Supply Voltage 200395D7 Output Power vs Load Resistance 200395D9 Power Dissipation vs Output Power 200395E1 11 200395D8 200395E0 ...

  • Page 12

    Typical Performance Characteristics Supply Current vs Supply Voltage Frequency Response www.national.com (Continued) Channel Separation 200395C9 Frequency Response 200395D4 Frequency Response 200395D6 12 200395D0 200395D5 ...

  • Page 13

    Typical Performance Characteristics Output Mode gain from gain from LIN/RIN to LOUT/ROUT A - weighted filter used (Continued) Output Noise vs Output Mode (V = 3V, 5V) DD ...

  • Page 14

    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 15

    APPLICATION INFORMATION TABLE 3. Volume Control Settings Gain (dB Phone_In_HS OUT OUT OUT OUT -34.5 -40.5 -33.0 -39.0 -31.5 -37.5 -30.0 -360 -28.5 -34.5 -27.0 ...

  • Page 16

    ... LM4855’s thermal shutdown protection. Further detailed and specific information con- cerning PCB layout and fabrication and mounting an LD (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 17

    APPLICATION INFORMATION (Continued) 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 maximum output power. A poorly regulated supply’s ...

  • Page 18

    APPLICATION INFORMATION (Continued) voltage, increase the load impedance, or reduce the ambient temperature. If these measures are insufficient, a heat sink can be added to reduce θ . The heat sink can be created JA using additional copper area around ...

  • Page 19

    Demonstration Board Layout FIGURE 3. Recommended IBL, ITL PC Board Layout: Top Silkscreen FIGURE 5. Recommended IBL, ITL PC Board Layout: Middle Layer 200395A7 FIGURE 4. Recommended IBL, ITL PC Board Layout: Top Layer 200395A5 FIGURE 6. Recommended IBL, ITL ...

  • Page 20

    Demonstration Board Layout FIGURE 7. Recommended LD PC Board Layout: Top Silkcreen Layer FIGURE 9. Recommended LD PC Board Layout: Inner Layer 1 www.national.com (Continued) 200395E5 FIGURE 8. Recommended LD PC Board Layout: Top Layer 200395E7 FIGURE 10. Recommended LD ...

  • Page 21

    Demonstration Board Layout FIGURE 11. Recommended LD PC Board Layout: Bottom Layer (Continued) 200395E9 21 www.national.com ...

  • Page 22

    Physical Dimensions X www.national.com inches (millimeters) unless otherwise noted 18-Bump mciro SMD Order Number LM4855IBL NS Package Number BLA18AAB Dimensions are in millimeteres ± ± = 1.996 0. 2.225 0. ± = 0.945 ...

  • Page 23

    Physical Dimensions inches (millimeters) unless otherwise noted (Continued) 24-Lead MOLDED PKG, Leadless Leadframe Package LLP Order Number LM4855LQ NS Package Number LQA24A 23 www.national.com ...

  • Page 24

    ... 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 ...