参数资料
型号: MAX9756ETX+T
厂商: Maxim Integrated Products
文件页数: 16/31页
文件大小: 0K
描述: IC AMP AUDIO PWR 2.3W AB 36TQFN
标准包装: 2,500
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: 带卷 (TR)
Flying Capacitor (C1)
The value of the flying capacitor (C1) affects the load
regulation and output resistance of the charge pump. A
C1 value that is too small degrades the device’s ability to
provide sufficient current drive, which leads to a loss of
output voltage. Increasing the value of C1 improves load
regulation and reduces the charge-pump output resis-
tance to an extent. See the Output Power vs. Charge-
Pump Capacitance graph in the Typical Operating
Characteristics. Above 2.2F, the on-resistance of the
switches and the ESR of C1 and C2 dominate.
Output Capacitor (C2)
The output capacitor value and ESR directly affect the
ripple at CPVSS. Increasing the value of C2 reduces
output ripple. Likewise, decreasing the ESR of C2
reduces both ripple and output resistance. Lower
capacitance values can be used in systems with low
maximum output power levels. See the Output Power
vs. Charge-Pump Capacitance graph in the Typical
Operating Characteristics.
CPVDD Bypass Capacitor
The CPVDD bypass capacitor (C3) lowers the output
impedance of the power supply and reduces the impact
of the MAX9756/MAX9757/MAX9758’s charge-pump
switching transients. Bypass CPVDD with C3, the same
value as C1, and place it physically close to CPVDD and
PGND (refer to the MAX9756/MAX9757/MAX9758
Evaluation Kit for a suggested layout).
Powering Other Circuits
from a Negative Supply
An additional benefit of the MAX9756/MAX9757/
MAX9758 is the internally generated negative supply
voltage (CPVSS). CPVSS is used by the MAX9756/
MAX9757/MAX9758 to provide the negative supply for
the headphone amplifiers. It can also be used to power
other devices within a design. Current draw from
CPVSS should be limited to 5mA; exceeding this affects
the operation of the headphone amplifier. A typical
application is a negative supply to adjust the contrast
of LCD modules.
When considering the use of CPVSS in this manner,
note that the charge-pump voltage of CPVSS is roughly
proportional to CPVDD and is not a regulated voltage.
Layout and Grounding
Proper layout and grounding are essential for optimum
performance. Use large traces for the power-supply
inputs and amplifier outputs to minimize losses due to
parasitic trace resistance, as well as route heat away
from the device. Good grounding improves audio per-
formance, minimizes crosstalk between channels, and
prevents any switching noise from coupling into the
audio signal. Connect CPGND, PGND, and GND
together at a single point on the PC board. Route
CPGND and all traces that carry switching transients
away from GND, PGND, and the traces and compo-
nents in the audio signal path.
Connect all components associated with the charge
pump (C2 and C3) to the CPGND plane. Connect VSS
and CPVSS together at the device. Place the charge-
pump capacitors (C1, C2, and C3) as close to the
device as possible. Bypass HPVDD and PVDD with a
1F capacitor to GND. Place the bypass capacitors as
close to the device as possible.
Use large, low-resistance output traces. As load imped-
ance decreases, the current drawn from the device out-
puts increase. At higher current, the resistance of the
output traces decrease the power delivered to the load.
For example, when compared to a 0
trace, a 100m
trace reduces the power delivered to a 4
load from
2.1W to 2W. Large output, supply, and GND traces also
improve the power dissipation of the device. The
MAX9756/MAX9757/MAX9758 thin QFN package fea-
tures an exposed thermal pad on its underside. This pad
lowers the package’s thermal resistance by providing a
direct-heat conduction path from the die to the PC
board. Connect the exposed thermal pad to GND by
using a large pad and multiple vias to the GND plane.
MAX9756/MAX9757/MAX9758
2.3W Stereo Speaker Amplifiers and DirectDrive
Headphone Amplifiers with Automatic Level Control
______________________________________________________________________________________
23
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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
MAX9758ETJ+ 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
MAX9758ETJ+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