參數(shù)資料
型號(hào): MAX4298
廠商: Maxim Integrated Products, Inc.
英文描述: Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
中文描述: 超高PSRR立體聲驅(qū)動(dòng)器 + 麥克風(fēng)放大器 + 100mA線性穩(wěn)壓器
文件頁(yè)數(shù): 8/14頁(yè)
文件大?。?/td> 311K
代理商: MAX4298
M
Ultra-High PS RR S tereo Drivers +
Mic rophone Amp + 100mA Linear Regulator
8
_______________________________________________________________________________________
MAX4298 block diagram and Figure 2 is the MAX4299
block diagram.
The amplifiers exhibit better than 115dB of DC power-
supply rejection and 93dB at 20kHz. The output ampli-
fiers are capable of driving a 1.5V
RMS
signal into 10k
load with 0.0008% distortion. They can also drive 32
headphones to 1.2V
RMS
with 0.02% distortion. At
+3.3V, the linear regulator can output 100mA of current.
BIAS
The common-mode bias point for the amplifiers is set to
2.25V by internal circuitry that has two functions. It pro-
vides a clickless/popless power-up/power-down wave-
form for the amplifiers. Also, it generates a ground-
referenced bias voltage with ultra-high power-supply
rejection ratio (PSRR). BIAS should be bypassed with 1μF
to GND.The output impedance of the BIAS pin is 50k
.
Clickless/Popless Function
The MAX4298/MAX4299 are designed for high-fidelity
audio performance into AC-coupled loads. Patented
design techniques achieve a clickless/popless power-up
sequence, and the use of a low-current standby supply
(SV
CC
) or external Schottky diode/reservoir capacitor
combination allows clickless/popless power-down. A
clickless/popless mute function is also provided to main-
tain a low impedance output when the input signal is
switched off.
Mute Function
The MAX4298/MAX4299 have a MUTE pin that allows the
user to mute the outputs of the device. This feature dis-
connects the input signal from the power amplifiers when
a logic high is present at the MUTE pin. To ensure proper
functionality, the MUTE pin should always be tied to either
V
CC
or GND. MUTE only affects the headphone driver
outputs. REG, BIAS, and MICOUT are unaffected. OUT1
and OUT2 are muted, but remain in a low-impedance
state to ensure clickless/popless operation.
SV
CC
The MAX4298/MAX4299 provide a fully clickless power-
down sequence. SV
CC
can either be connected to a low-
current +5V power source or alternatively can be
connected with a reservoir capacitor to ground and a
Schottky diode to V
CC
. A reservoir capacitor of 220μF or
higher provides enough charge for the clickless power-
down sequence when C
BIAS
= 1μF. For larger values of
C
BIAS
, increase the reservoir capacitor accordingly.
Short to V
CC
if clickless power-down is not needed.
Driver Amplifier
The headphone driver amplifier is a class AB amplifier
designed to drive 16
loads. The amplifiers have innov-
ative architectures for both the input and output stages
to achieve ultra-high PSRR while maintaining rail-to-rail
output drive capability. The output stage can drive high
capacitive loads encountered when driving long cables
used for desktop speakers or headphones.
Microphone Preamplifier (MAX 4299)
The MAX4299 provides a microphone preamplifier that
is a low-power version of the audio amplifier. It is intend-
ed to be used for low-level signal amplification. This
microphone preamplifier provides rail-to-rail output with
very high PSRR.
C
BYPASS
IN1
V
CC
SV
CC
OUT1
MUTE
OUT2
GND
MAX4298
IN2
BIAS
+
_
50k
2.25V
_
+
Figure 1. MAX4298 Block Diagram
C
BYPASS
OUT1
MICIN
GND
MAX4299
MICOUT
MUTE
IN2
BIAS
IN1
1.233V
FB
V
CC
SV
CC
REGON
REG
18.4k
11k
50k
OUT2
N.C.
_
+
2.25V
+
_
+
_
+
_
PGND
Figure 2. MAX4299 Block Diagram
相關(guān)PDF資料
PDF描述
MAX4298ESD Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
MAX4299 Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
MAX4299EUE Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
MAX4298EUB Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
MAX4299EWP Ultra-High PSRR Stereo Drivers + Microphone Amp + 100mA Linear Regulator
相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX4298ESD 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX4298ESD+ 功能描述:音頻放大器 High PSRR Stereo Driver + Mic Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX4298ESD+T 功能描述:音頻放大器 High PSRR Stereo Driver + Mic Amp RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX4298ESD-T 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel
MAX4298EUB 功能描述:音頻放大器 RoHS:否 制造商:STMicroelectronics 產(chǎn)品:General Purpose Audio Amplifiers 輸出類型:Digital 輸出功率: THD + 噪聲: 工作電源電壓:3.3 V 電源電流: 最大功率耗散: 最大工作溫度: 安裝風(fēng)格:SMD/SMT 封裝 / 箱體:TQFP-64 封裝:Reel