参数资料
型号: MAX9770EUI+T
厂商: Maxim Integrated Products
文件页数: 6/22页
文件大小: 0K
描述: IC AMP AUDIO 1.2W MONO D 28TSSOP
标准包装: 2,500
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: 1.2W x 1 @ 8 欧姆; 80mW x 2 @ 16 欧姆
电源电压: 2.5 V ~ 5.5 V
特点: 消除爆音,输入多路复用器,静音,短路和热保护,关机
安装类型: 表面贴装
供应商设备封装: 28-TSSOP
封装/外壳: 28-TSSOP(0.173",4.40mm 宽)
包装: 带卷 (TR)
Maxim’s DirectDrive architecture uses a charge pump to
create an internal negative supply voltage. This allows
the headphone outputs of the MAX9770 to be biased
about GND, almost doubling dynamic range while oper-
ating from a single supply. With no DC component, there
is no need for the large DC-blocking capacitors. Instead
of two large (220F, typ) tantalum capacitors, the
MAX9770 charge pump requires two small ceramic
capacitors, which conserves board space, reduces cost,
and improves the frequency response of the headphone
driver. See the Output Power vs. Charge-Pump
Capacitance and Load Resistance graph in the
Typical
Operating Characteristics for details of the possible
capacitor sizes. There is a low DC voltage on the driver
outputs due to amplifier offset. However, the offset of the
MAX9770 is typically 5mV, which, when combined with a
32
Ω load, results in less than 160A of DC current flow
to the headphones.
In addition to the cost and size disadvantages of the DC-
blocking capacitors required by conventional head-
phone amplifiers, these capacitors limit the amplifier’s
low-frequency response and can distort the audio signal.
Previous attempts at eliminating the output-coupling
capacitors involved biasing the headphone return
(sleeve) to the DC bias voltage of the headphone
amplifiers. This method raises some issues:
1) When combining a microphone and headphone on a
single connector, the microphone bias scheme typi-
cally requires a 0V reference.
2) The sleeve is typically grounded to the chassis.
Using the midrail biasing approach, the sleeve must
be isolated from system ground, complicating prod-
uct design.
3) During an ESD strike, the driver’s ESD structures are
the only path to system ground. Thus, the driver
must be able to withstand the full ESD strike.
4) When using the headphone jack as a line out to
other equipment, the bias voltage on the sleeve may
conflict with the ground potential from other equip-
ment, resulting in possible damage to the drivers.
MAX9770
1.2W, Low-EMI, Filterless, Mono Class D Amplifier
with Stereo DirectDrive Headphone Amplifiers
14
______________________________________________________________________________________
0
30
20
10
50
40
90
80
70
60
100
0
0.1
0.2
0.4
0.3
0.5
0.6
EFFICIENCY vs. OUTPUT POWER
OUTPUT POWER (W)
EFFICIENCY
(%)
MAX9770
CLASS AB
VDD = 3.3V
f = 1kHz
RL - 8
Ω
Figure 5. MAX9770 Efficiency vs. Class AB Efficiency
MAX9770
800k
Ω
10k
Ω
10k
Ω
VDD
HPS
HPOUTL
HPOUTR
SHUTDOWN
CONTROL
SHDN
Figure 6. HPS Configuration
VIN = 0V
OUT-
OUT+
VOUT+ - VOUT- = 0V
Figure 4. MAX9770 Output with No Signal Applied
相关PDF资料
PDF描述
MAX9773EBP+TG45 IC AMP AUDIO PWR 1.8W D 20UCSP
MAX9776ETJ+T IC AMP AUDIO PWR 1.5W D 32TQFN
MAX9778ETI+ IC AMP AUDIO PWR 2.6W AB 28TQFN
MAX9779ETI+T IC AMP AUDIO PWR 2.6W AB 28TQFN
MAX977EEE+ IC COMPARATOR DUAL 16-QSOP
相关代理商/技术参数
参数描述
MAX9770EVKIT 功能描述:音频 IC 开发工具 Programmers, Development Systems RoHS:否 制造商:Texas Instruments 产品:Evaluation Kits 类型:Audio Amplifiers 工具用于评估:TAS5614L 工作电源电压:12 V to 38 V
MAX9772EBA 制造商:Maxim Integrated Products 功能描述:1.2WLOW-EMIFILTERLESSMONO CLASS - Rail/Tube
MAX9772EBA-T 制造商:Maxim Integrated Products 功能描述:1.2W,LOW-EMI,FILTERLESS,MONO CLASS D AMP. W S - Tape and Reel
MAX9773EBP+TG45 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
MAX9773ETG+ 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