参数资料
型号: MAX9879ERV+T
厂商: Maxim Integrated Products
文件页数: 13/32页
文件大小: 0K
描述: IC AUDIO SUBSYSTEM 30-UCSP
产品培训模块: Lead (SnPb) Finish for COTS
Obsolescence Mitigation Program
标准包装: 2,500
系列: DirectDrive®
类型: D 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: 715mW x 2 @ 8 欧姆; 58mW x 2 @ 16 欧姆
电源电压: 2.7 V ~ 5.5 V
特点: 消除爆音,差分输入,I²C,静音,短路和热保护,关机,音量控制
安装类型: 表面贴装
供应商设备封装: 30-UCSP(5x6)
封装/外壳: 30-WFBGA,CSPBGA
包装: 带卷 (TR)
MAX9879
Stereo Class D Audio Subsystem
with DirectDrive Headphone Amplifier
20
Maxim Integrated
DirectDrive Headphone Amplifier
Traditional single-supply headphone amplifiers have
outputs biased at a nominal DC voltage (typically half
the supply). Large coupling capacitors are needed to
block this DC bias from the headphone. Without these
capacitors, a significant amount of DC current flows to
the headphone, resulting in unnecessary power dissi-
pation and possible damage to both the headphone
and headphone amplifier.
Maxim’s DirectDrive architecture uses a charge pump
to create an internal negative supply voltage. This
allows the headphone outputs of the MAX9879 to be
biased at GND while operating from a single supply
(Figure 5). Without a DC component, there is no need
for the large DC-blocking capacitors. Instead of two
large (220F, typ) capacitors, the MAX9879 charge
pump requires two small ceramic capacitors, conserv-
ing board space, reducing cost, and improving the fre-
quency response of the headphone amplifier. See the
Output Power vs. Load Resistance graph in the
Typical
Operating Characteristics for details of the possible
capacitor sizes. There is a low DC voltage on the ampli-
fier outputs due to amplifier offset. However, the offset of
the MAX9879 is typically ±1.5mV, which, when com-
bined with a 32
Ω load, results in less than 47A 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 sig-
nal. Previous attempts at eliminating the output-cou-
pling capacitors involved biasing the headphone return
(sleeve) to the DC bias voltage of the headphone
amplifiers. This method raises some issues:
FREQUENCY (MHz)
AMPLITUDE
(dB
μ
V/m)
160
140
120
100
80
60
10
15
20
25
30
35
40
TEST LIMIT
MAX9879 OUTPUT
TEST LIMIT
5
30
180
200
240
260
280
300
220
FREQUENCY (MHz)
AMPLITUDE
(dB
μ
V/m)
600
550
500
450
400
350
15
20
25
35
40
10
300
650
700
800
850
900
1000
950
750
Figure 4. EMI with 152mm of Speaker Cable
DirectDrive is a registered trademark of Maxim Integrated
Products, Inc.
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MAX9879EVKIT+ 功能描述:音频放大器 Stereo Class D Audio Subsystem with DirectDrive Headphone Amplifier 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
MAX987ESA 功能描述:校验器 IC Single uPower Comparator RoHS:否 制造商:STMicroelectronics 产品: 比较器类型: 通道数量: 输出类型:Push-Pull 电源电压-最大:5.5 V 电源电压-最小:1.1 V 补偿电压(最大值):6 mV 电源电流(最大值):1350 nA 响应时间: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SC-70-5 封装:Reel
MAX987ESA+ 功能描述:校验器 IC Single uPower Comparator RoHS:否 制造商:STMicroelectronics 产品: 比较器类型: 通道数量: 输出类型:Push-Pull 电源电压-最大:5.5 V 电源电压-最小:1.1 V 补偿电压(最大值):6 mV 电源电流(最大值):1350 nA 响应时间: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SC-70-5 封装:Reel
MAX987ESA+T 功能描述:校验器 IC Single uPower Comparator RoHS:否 制造商:STMicroelectronics 产品: 比较器类型: 通道数量: 输出类型:Push-Pull 电源电压-最大:5.5 V 电源电压-最小:1.1 V 补偿电压(最大值):6 mV 电源电流(最大值):1350 nA 响应时间: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SC-70-5 封装:Reel
MAX987ESA-T 功能描述:校验器 IC Single uPower Comparator RoHS:否 制造商:STMicroelectronics 产品: 比较器类型: 通道数量: 输出类型:Push-Pull 电源电压-最大:5.5 V 电源电压-最小:1.1 V 补偿电压(最大值):6 mV 电源电流(最大值):1350 nA 响应时间: 最大工作温度:+ 125 C 安装风格:SMD/SMT 封装 / 箱体:SC-70-5 封装:Reel