参数资料
型号: MAX9792CETI+
厂商: Maxim Integrated Products
文件页数: 14/34页
文件大小: 0K
描述: IC AMP AUDIO 2.0W STER D 28TQFN
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 1
系列: DirectDrive®
类型: D 类
输出类型: 1-通道(单声道),带立体声耳机
在某负载时最大输出功率 x 通道数量: 3.7W x 1 @ 3 欧姆; 180mW x 2 @ 32 欧姆
电源电压: 4.5 V ~ 5.5 V
特点: 消除爆音,LDO,短路保护和热保护,关机
安装类型: 表面贴装
供应商设备封装: 28-TQFN-EP(4x4)
封装/外壳: 28-WFQFN 裸露焊盘
包装: 管件
MAX9791/MAX9792
Windows Vista-Compliant Class D Speaker
Amplifiers with DirectDrive Headphone Amplifiers
______________________________________________________________________________________
21
Common-Mode Sense
Windows Vista-compliant platforms are restricted to only
115m
of ground return impedance. If the headphone
jack ground is connected close to the audio device
ground using a solid ground plane, the return path resis-
tance can be quite low. However, it is often necessary to
locate some jacks far from the audio device. The
MAX9791/MAX9792 COM and SENSE inputs allow the
headphone jack to be placed further away from the
device without degrading crosstalk performance.
The MAX9791/MAX9792 SENSE and COM inputs sense
and correct for the difference between the headphone
return and device ground. When using common-mode
sense, connect COM through a resistor to GND of the
device (Figure 4). For optimum common-mode rejec-
tion, use the same value resistors for RIN2 and RCOM.
To improve AC CMRR, add a capacitor equal to CIN2
between GND and RCOM.
Configuring SENSE and COM in this way improves sys-
tem crosstalk performance by reducing the negative
effects of the headphone jack ground return resistance.
The headphone amplifier output impedance, trace
resistance, and contact resistance of the jack are
grouped together to represent the source resistance,
RS. The resistance between the load and the sleeve,
the sleeve contact resistance, and the system ground
return resistance are grouped together to represent the
ground resistance, RG.
Assuming a typical source resistance of 5
, the ground
return impedance would need to be limited to 115m
to meet Windows Vista’s crosstalk specification of 50dB
(Figure 5). This is further complicated by the fact that
the impedance of the sleeve connection in the 3.5mm
stereo jack can make up 30m
–90m alone.
The MAX9791/MAX9792 COM and SENSE inputs
reduce crosstalk performance by eliminating effects of
28.5m
of ground return path resistance. If ground
sensing is not required, connect COM directly to GND
and leave SENSE unconnected (Figure 6).
Wake-on-Beep
The MAX9791/MAX9792 beep-detection circuit wakes
up the device (speaker and headphone amplifiers)
once a qualified beep signal is detected at BEEP and
the LDO is enabled. The amplifier wake command from
the beep-detection circuit overrides the logic signal
applied at HP_EN and SPKR_EN.
Crosstalk in dB
R
RR
G
LS
=
+
20 log
RIN2
RFHP
COM
HP_INL
HPL
RCOM
SENSE
RIN2
HP_INR
HPR
CIN2
CCOM
CIN2
Figure 4. Connecting COM for Ground Sense
-80
-75
-70
-65
-60
-55
-50
-45
-40
0
0.050
0.025
0.075
0.100
0.125
0.150
CROSSTALK
vs. GROUND RESISTANCE (RG)
RG (
)
CROSSTALK
(dB)
RS = 5
RL = 32
Figure 5. Crosstalk vs. Ground Resistance
相关PDF资料
PDF描述
MS27505E11F35SA CONN RCPT 13POS BOX MNT W/SCKT
D38999/26WD97BN CONN HSG PLUG 12POS STRGHT SCKT
LTC1096LCS8#TR IC ADC 8BIT SERIAL I/O 3V 8SOIC
MS3101F10SL-4P CONN RCPT 2POS FREE HNG W/PINS
LTC1199LIMS8 IC ADC 10BIT 210KHZ W/SD 8-MSOP
相关代理商/技术参数
参数描述
MAX9792CETI+ 功能描述:音频放大器 Windows Vista Class D Speaker Amp 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
MAX9792CETI+T 功能描述:音频放大器 Windows Vista Class D Speaker Amp 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
MAX9796EBX+TG45 功能描述:音频放大器 2.3W High-Power Class D Subsystem 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
MAX9796EVKIT 制造商:Maxim Integrated Products 功能描述:2.3W HIGH-POWER CLASS D AUDIO SUBS - Rail/Tube
MAX9796EVKIT+ 制造商:Maxim Integrated Products 功能描述:MAX9796 EVAL KIT - Boxed Product (Development Kits)