欢迎访问ic37.com |
会员登录 免费注册
发布采购

EUA4996JIR1 参数 Datasheet PDF下载

EUA4996JIR1图片预览
型号: EUA4996JIR1
PDF下载: 下载PDF文件 查看货源
内容描述: 2.8 W立体声全差分音频功率放大器 [2.8-W Stereo Fully Differential Audio Power Amplifier]
分类和应用: 放大器功率放大器
文件页数/大小: 12 页 / 895 K
品牌: EUTECH [ EUTECH MICROELECTRONICS INC ]
 浏览型号EUA4996JIR1的Datasheet PDF文件第4页浏览型号EUA4996JIR1的Datasheet PDF文件第5页浏览型号EUA4996JIR1的Datasheet PDF文件第6页浏览型号EUA4996JIR1的Datasheet PDF文件第7页浏览型号EUA4996JIR1的Datasheet PDF文件第8页浏览型号EUA4996JIR1的Datasheet PDF文件第9页浏览型号EUA4996JIR1的Datasheet PDF文件第10页浏览型号EUA4996JIR1的Datasheet PDF文件第12页  
EUA4996  
Proper Selection of External Components  
Gain-Setting Resistor Selection  
The input resistor (RI) can be selected to set the gain of  
the amplifier according to equation2.  
The value of CI is important to consider as it directly  
affects the bass (low frequency) performance of the  
circuit.  
Consider the example where RI is 10kand the  
specification calls for a flat bass response down to 100Hz.  
Equation 3 is reconfigured as equation4.  
Gain=RF/RI  
(2)  
1
The internal feedback resistors (RF) are trimmed to  
C =  
(4)  
I
2π R f  
40k.  
I C  
Resistor matching is very important in fully differential  
amplifiers. The balance of the output on the reference  
voltage depends on matched ratios of the resistors.  
CMRR, PSRR, and the cancellation of the second  
harmonic distortion diminishes if resistor mismatch  
occurs. Therefore, it is recommended to use 1%  
tolerance resistors or better to keep the performance  
optimized.  
In this example, CI is 0.16µF, so one would likely choose  
a value in the range of 0.22µF to 0.47µF.  
Ceramic capacitors should be used when possible, as they  
are the best choice in preventing leakage current. When  
polarized capacitors are used, the positive side of the  
capacitor should face the amplifier input in most  
applications, as the dc level there is held at VDD/2, which  
is likely higher than the source dc level. It is important to  
confirm the capacitor polarity in the application.  
Bypass Capacitors (CBYPASS) and Start-up Time  
The internal voltage divider at the Bypass pin of this  
device sets a mid-supply voltage for internal references  
and sets the output common mode voltage to VDD/2.  
Adding a capacitor to this pin filters any noise into this  
pin and increases kSVR. C(BYPASS) also determines the rise  
time of VO+ and VO- when the device is taken out of  
shutdown. The larger the capacitor, the slower the rise  
time. IF Bypass Capacitors are used, it is necessary to  
use separate bypass capacitors for each bypass pin.  
Decoupling Capacitor (CS)  
The EUA4996 is a high-performance CMOS audio  
amplifier that requires adequate power supply decoupling  
to ensure the output total harmonic distortion (THD) is as  
low as possible. Power supply decoupling also prevents  
oscillations for long lead lengths between the amplifier  
and the speaker. For higher frequency transients, spikes,  
or digital hash on the line,  
a
good low  
equivalent-series-resistance (ESR) ceramic capacitor,  
typically 0.1µF to 1 µF, placed as close as possible to the  
device VDD lead works best. For filtering lower frequency  
noise signals, a 10-µF or greater capacitor placed near the  
audio power amplifier also helps, but is not required in  
most applications because of the high PSRR of this  
device.  
Input Capacitor (CI)  
The EUA4996 does not require input coupling  
capacitors if using a differential input source that is  
biased from 0.5V to VDD -0.8V. Use 1% tolerance or  
better gain-setting resistors if not using input coupling  
capacitors.  
Each VDD pin must have a separate power supply  
decoupling capacitor. Additionally, the left and high  
channel VDD pins must be tied together on the PCB.  
In the single-ended input application an input capacitor,  
CI, is required to allow the amplifier to bias the input  
signal to the proper dc level. In this case, CI and RI form  
a high-pass filter with the corner frequency determined  
in equation3.  
1
f
=
(3)  
C
2π R C  
I I  
DS4996 Ver0.1 July 2008  
11