参数资料
型号: MAX9756ETX+
厂商: Maxim Integrated Products
文件页数: 15/31页
文件大小: 0K
描述: IC AMP AUDIO PWR 2.3W AB 36TQFN
标准包装: 50
系列: DirectDrive®
类型: AB 类
输出类型: 2-通道(立体声)带立体声耳机
在某负载时最大输出功率 x 通道数量: 2.3W x 2 @ 3 欧姆; 130mW x 2 @ 16 欧姆
电源电压: 4.5 V ~ 5.5 V
特点: 消除爆音,短路保护和热保护,关机,音量控制
安装类型: 表面贴装
供应商设备封装: 36-TQFN 裸露焊盘(6x6)
封装/外壳: 36-WFQFN 裸露焊盘
包装: 管件
MAX9756/MAX9757/MAX9758
Output Power (Headphone Amplifier)
The headphone amplifiers have been specified for the
worst-case scenario—when both inputs are in phase.
Under this condition, the drivers simultaneously draw
current from the charge pump, leading to a slight loss
in headroom of VSS. In typical stereo audio applica-
tions, the left and right signals have differences in both
magnitude and phase, subsequently leading to an
increase in the maximum attainable output power.
Figure 14 shows the two extreme cases for in and out
of phase. In reality, the available power lies between
these extremes.
Power Supplies
The MAX9756/MAX9757/MAX9758 have different sup-
plies for each portion of the device, allowing for the opti-
mum combination of headroom and power dissipation
and noise immunity. The speaker amplifiers are pow-
ered from PVDD. PVDD ranges from 4.5V to 5.5V. The
headphone amplifiers are powered from HPVDD and
VSS. HPVDD is the positive supply of the headphone
amplifiers and ranges from 3V to 5.5V. VSS is the nega-
tive supply of the headphone amplifiers. Connect VSS to
CPVSS. The charge pump is powered by CPVDD.
CPVDD ranges from 3V to 5.5V and should be the same
potential as HPVDD. The charge pump inverts the volt-
age at CPVDD, and the resulting voltage appears at
CPVSS. The remainder of the device is powered by VDD.
Component Selection
Input Filtering
The input capacitor (CIN), in conjunction with the ampli-
fier input resistance (RIN), forms a highpass filter that
removes the DC bias from an incoming signal (see the
Typical Application Circuit). The AC-coupling capacitor
allows the amplifier to bias the signal to an optimum DC
level. Assuming zero source impedance, the -3dB point
of the highpass filter is given by:
RIN is the amplifier’s internal input resistance value
given in the Electrical Characteristics. Choose CIN such
that f-3dB is well below the lowest frequency of interest.
Setting f-3dB too high affects the amplifier’s low-fre-
quency response. Use capacitors with low-voltage
coefficient dielectrics, such as tantalum or aluminum
electrolytic. Capacitors with high-voltage coefficients,
such as ceramics, may result in increased distortion at
low frequencies.
BIAS Capacitor
BIAS is the output of the internally generated DC bias
voltage. The BIAS bypass capacitor, CBIAS, improves
PSRR and THD+N by reducing power supply and other
noise sources at the common-mode bias node, and
also generates the startup/shutdown DC bias wave-
forms for the speaker amplifiers. Bypass BIAS with a
1F capacitor to GND.
Charge-Pump Capacitor Selection
Use capacitors with an ESR less than 100m
for opti-
mum performance. Low-ESR ceramic capacitors mini-
mize the output resistance of the charge pump. For
best performance over the extended temperature
range, select capacitors with an X7R dielectric. Table 6
lists suggested manufacturers.
f
RC
dB
IN IN
=
3
1
2
π
2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control
22
______________________________________________________________________________________
OUTPUT POWER (mW)
THD+N
(%)
160
140
100 120
60 80
20 40
0.01
0.1
1
10
100
0.001
0
200
180
HPVDD = 5V
RL = 16
OUTPUTS 180
° OUT OF PHASE
OUTPUTS IN PHASE
Figure 14. Total Harmonic Distortion Plus Noise vs. Output
Power with Inputs In/Out of Phase (Headphone Mode)
Table 6. Suggested Capacitor Manufacturers
SUPPLIER
PHONE
FAX
WEBSITE
Taiyo Yuden
800-384-2496
800-925-0899
www.t-yuden.com
TDK
807-803-6100
847-390-4405
www.component.tdk.com
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MAX9756ETX+ 功能描述:音频放大器 Integrated Circuits (ICs) RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel
MAX9756ETX+T 功能描述:音频放大器 Integrated Circuits (ICs) RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel
MAX9756EVKIT 功能描述:放大器 IC 开发工具 Programmers, Development Systems RoHS:否 制造商:International Rectifier 产品:Demonstration Boards 类型:Power Amplifiers 工具用于评估:IR4302 工作电源电压:13 V to 23 V
MAX9757ETJ+ 功能描述:音频放大器 Integrated Circuits (ICs) RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel
MAX9757ETJ+T 功能描述:音频放大器 Integrated Circuits (ICs) RoHS:否 制造商:STMicroelectronics 产品:General Purpose Audio Amplifiers 输出类型:Digital 输出功率: THD + 噪声: 工作电源电压:3.3 V 电源电流: 最大功率耗散: 最大工作温度: 安装风格:SMD/SMT 封装 / 箱体:TQFP-64 封装:Reel