查莉成长日记第二季LM4906
1W,Bypass-Capacitor-less Audio Amplifier with Internal Selectable Gain
General Description
The LM4906is an audio power amplifier primarily designed for demanding applications in mobile phones and other por-table communication device applications.It is capable of delivering 1W of continuous average power to an 8ΩBTL load with less than 1%distortion (THD+N)from a +5V power supply.ly
The LM4906is the first National Semiconductor Boomer Power Amplifier that does not require an ext
ernal PSRR bypass capacitor.The LM4906also has an internal lect-able gain of either 6dB or 12dB.In addition,no output coupling capacitors or bootstrap capacitors are required which makes the LM4906ideally suited for cell phone and other low voltage portable applications.
The LM4906contains advanced pop and click circuitry that eliminates noi,which would otherwi occur during turn-on and turn-off transitions.
Boomer audio power amplifiers were designed specifically to provide high quality output power with a minimal amount of external components.The LM4906features a low -power consumption shutdown mode (the part is enabled by pulling the SD pin high).Additionally,the LM4906features an inter-nal thermal shutdown protection mechanism.
Key Specifications
j Improved PSRR at 217Hz for +3V 71dB j Power Output at +5V,THD+N =1%,8Ω 1.0W (typ)j Power Output at +3V,THD+N =1%,8Ω390mW (typ)
j Total shutdown power supply current
0.1µA (typ)
Features大学英语精读第四册答案
n Selectable gain of 6dB (2V/V)or 12dB (4V/V)n No output or PSRR bypass capacitors required n Improved “Click and Pop”suppression circuitry n Very fast turn on time:5ms (typ)n Minimum external components n 2.6-5.5V operation
n BTL output can drive capacitive loads
n
Ultra low current shutdown mode (SD Low)
Applications
n Portable computers n Desktop computers n Multimedia monitors
Typical Application
Boomer ®is a registered trademark of National Semiconductor Corporation.
200571B9
FIGURE 1.Typical Audio Amplifier Application Circuit
May 2003
LM49061W,Bypass-Capacitor-less Audio Amplifier with Internal Selectable Gain
©2003National Semiconductor Corporation
Connection Diagrams
MSOP Package
MSOP Marking
20057102Top View
Order Number LM4906MM See NS Package Number MUB08A
200571F1
Z -Plant Code X -Date Code T -Die Traceability
LLP Package
LD Marking
200571C3
Top View
Order Number LM4906LD
See NS Package Number LDA10B
200571F2
Z -Plant Code XY -Date Code T -Die Traceability
L M 4906
2
Absolute Maximum Ratings(Note2) If Military/Aerospace specified devices are required, plea contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Supply Voltage(Note10) 6.0V Storage Temperature−65˚C to+150˚C Input Voltage−0.3V to V DD+0.3V Power Dissipation(Notes3,11)Internally Limited ESD Susceptibility(Note4)2000V ESD Susceptibility(Note5)200V Junction Temperature150˚C
Thermal Resistance
θJC(MSOP)56˚C/W θJA(MSOP)190˚C/W θJC(LLP)12˚C/W θJA(LLP)63˚C/W Operating Ratings
Temperature Range
T MIN≤T A≤T MAX−40˚C≤T A≤85˚C Supply Voltage 2.6V≤V DD≤5.5V
Electrical Characteristics V
DD =5V(Notes1,2)
The following specifications apply for the circuit shown in Figure1,unless otherwi specified.Limits apply for T A=25˚C.
Symbol Parameter Conditions
LM4906
Units
(Limits) Typical Limit
(Note6)(Notes7,8)
I DD Quiescent Power Supply Current V IN=0V,I o=0A,No Load 3.57mA(max) V IN=0V,I o=0A,8ΩLoad48mA(max)
I SD Shutdown Current V SD=GND0.12µA(max) V OS Output Offt Voltage735mV(max)
P o Output Power THD+N=1%(max);f=1kHz
R L=8Ω
1.00.9W(min)
T WU Wake-up time5ms THD+N Total Harmonic Distortion+Noi P o=0.4Wrms;f=1kHz0.2%
PSRR Power Supply Rejection Ratio V ripple=200mV sine p-p
Input terminated with10Ω
Gain at6dB
67(f=
217Hz)
70(f=1kHz)
dB
V SDIH Shutdown Voltage Input High SD Pin High=Part On 1.5V(min) V SDIL Shutdown Voltage Input Low SD Pin Low=Part Off 1.3V(max)
Electrical Characteristics Vromeo must die
DD =3V(Notes1,2)
The following specifications apply for the circuit shown in Figure1,unless otherwi specified.Limits apply for T A=25˚C.
Symbol Parameter Conditions
LM4906
Units
(Limits) Typical Limit
(Note6)(Notes7,8)
I DD Quiescent Power Supply Current V IN=0V,I o=0A,No Load 2.66mA(max) V IN=0V,I o=0A,8ΩLoad37mA(max)
I SD Shutdown Current V SD=GND0.12µA(max) V OS Output Offt Voltage735mV(max)
P o Output Power THD+N=1%(max);f=1kHz
R L=8Ω
390mW
T WU Wake-up time4ms THD+N Total Harmonic Distortion+Noi P o=0.15Wrms;f=1kHz0.1%
PSRR Power Supply Rejection Ratio V ripple=200mV sine p-p
departmentInput terminated with10Ω
Gain at6dB
71(f=
217Hz)
73(f=1kHz)
dB
V SDIH Shutdown Voltage Input High SD Pin High=Part On 1.1V(min)
V SDIL Shutdown Voltage Input Low SD Pin Low=Part Off0.9V(max)
LM4906
3
Note 1:All voltages are measured with respect to the ground pin,unless otherwi specified.
Note 2:Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.Op
erating Ratings indicate conditions for which the device is functional,but do not guarantee specific performance limits.Electrical Characteristics state DC and AC electrical specifications under particular test conditions which guarantee specific performance limits.This assumes that the device is within the Operating Ratings.Specifications are not guaranteed for parameters where no limit is given;however,the typical value is a good indication of device performance.
英文金额大写Note 3:The maximum power dissipation must be derated at elevated temperatures and is dictated by T JMAX ,θJA ,and the ambient temperature T A .The maximum allowable power dissipation is P DMAX =(T JMAX –T A )/θJA or the number given in Absolute Maximum Ratings,whichever is lower.For the LM4906,e power derating curves for additional information.
Note 4:Human body model,100pF discharged through a 1.5k Ωresistor.Note 5:Machine Model,220pF–240pF discharged through all pins.Note 6:Typicals are measured at 25˚C and reprent the parametric norm.
Note 7:Limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 8:Datasheet min/max specification limits are guaranteed by design,test,or statistical analysis.
mba如何报名Note 9:R OUT is measured from the output pin to ground.This value reprents the parallel combination of the 10k Ωoutput resistors and the two 20k Ωresistors.Note 10:If the product is in Shutdown mode and V DD exceeds 6V (to a max of 8V V DD ),then most of the excess current will flow through the ESD protection circuits.If the source impedance limits the current to a max of 10mA,then the device will be protected.If the device is enabled when V DD is greater than 5.5V and less than 6.5V,no damage will occur,although operation life will be reduced.Operation above 6.5V with no current limit will result in permanent damage.
Note 11:Maximum power dissipation in the device (P DMAX )occurs at an output power level significantly below full output power.P DMAX can be calculated using Equation 1shown in the Application Information ction.It may also be obtained from the power dissipation graphs.
External Components Description
Components Functional Description
1.
C 2
Input coupling capacitor which blocks the DC voltage at the amplifiers input terminals.Also creates a
highpass filter with R i at f c =1/(2πR i C i ).Refer to the ction,Proper Selection of External Components ,for an explanation of how to determine the value of C i .
2.
福州话翻译C 1
Supply bypass capacitor which provides power supply filtering.Refer to the Power Supply Bypassing ction for information concerning proper placement and lection of the supply bypass capacitor.
L M 4906
4
Typical Performance Characteristics
THD+N vs Frequency V DD =5V,R L =8Ω,f =1kHz,PWR =500mW
THD+N vs Frequency V DD =3V,R L =8Ω,f =1kHz,PWR =250mW
200571C4200571C5
THD+N vs Power Out V DD =5V,R L =8Ω,f =1kHz THD+N vs Power Out V DD =3V,R L =8Ω,f =1kHz
200571C6200571C7
Power Supply Rejection Ratio
vs Frequency V DD =5V,R L =8ΩPower Supply Rejection Ratio
vs Frequency V DD =3V,R L =8Ω
200571E2
couchsurf
200571C9
LM4906
5
Typical Performance Characteristics
(Continued)
Noi Floor V DD =5V,R L =8Ω
80kHz Bandwith,Input to GND
Power Derating Curve
200571D0
200571E4
Power Dissipation
vs Output Power,V DD =5V Power Dissipation
vs Output Power,V DD =3V
200571D1
200571D2
Shutdown Hysteresis Voltage V DD =5V,SD Mode =V DD (High)Shutdown Hysteresis Voltage V DD =5V,SD Mode =V DD (Low)
200571D3200571D4
relevantL M 4906
6
