參數(shù)資料
型號: MAX4364-MAX4365
廠商: Maxim Integrated Products, Inc.
英文描述: 1.4W and 1W, Ultra-Small, Audio Power Amplifiers with Shutdown
中文描述: 1.4W輸出功率及1W,超小型,音頻功率放大器,帶有關(guān)斷
文件頁數(shù): 9/15頁
文件大小: 682K
代理商: MAX4364-MAX4365
Detailed Description
The MAX4364/MAX4365 bridged audio power ampli-
fiers can deliver 1.4W into 8
(MAX4364) or 1W into 8
(MAX4365) while operating from a single 5V supply.
These devices consist of two high-output-current op
amps configured as a bridge-tied load (BTL) amplifier
(see
Typical Application Circuit/Functional Diagram
).
The gain of the device is set by the closed-loop gain of
the input op amp. The output of the first amplifier
serves as the input to the second amplifier, which is
configured as an inverting unity-gain follower in both
devices. This results in two outputs, identical in magni-
tude, but 180
°
out of phase.
BIAS
The MAX4364/MAX4365 feature an internally generated
common-mode bias voltage of V
CC
/2 referenced to
GND. BIAS provides both click-and-pop suppression
and the DC bias level for the audio signal. BIAS is inter-
nally connected to the noninverting input of one amplifi-
er, and should be connected to the noninverting input
of the other amplifier for proper signal biasing (see
Typical Application Circuit/Functional Diagram
).
Choose the value of the bypass capacitor as described
in the
BIAS Capacitor
section.
Shutdown
The MAX4364/MAX4365 feature a 10nA, low-power
shutdown mode that reduces quiescent current con-
sumption. Pulling SHDN high disables the device
s bias
circuitry, the amplifier outputs go high impedance, and
BIAS is driven to GND. Connect SHDN to GND for nor-
mal operation.
Current Limit
The MAX4364/MAX4365 feature a current limit that pro-
tects the device during output short circuit and over-
load conditions. When both amplifier outputs are
shorted to either V
CC
or GND, the short-circuit protec-
tion is enabled and the amplifier enters a pulsing mode,
reducing the average output current to a safe level. The
amplifier remains in this mode until the overload or
short-circuit condition is removed.
Applications Information
Bridge-Tied Load
The MAX4364/MAX4365 are designed to drive a load
differentially in a BTL configuration. The BTL configura-
tion (Figure 1) offers advantages over the single-ended
configuration, where one side of the load is connected
to ground. Driving the load differentially doubles the
output voltage compared to a single-ended amplifier
under similar conditions. Thus, the differential gain of
the device is twice the closed-loop gain of the input
amplifier. The effective gain is given by:
Substituting 2
V
OUT(P-P)
into the following equations
yields four times the output power due to doubling of
the output voltage.
Since the differential outputs are biased at midsupply,
there is no net DC voltage across the load. This elimi-
nates the need for DC-blocking capacitors required for
single-ended amplifiers. These capacitors can be
large, expensive, consume board space, and degrade
low-frequency performance.
Power Dissipation
Under normal operating conditions, the MAX4364/
MAX4365 can dissipate a significant amount of power.
The maximum power dissipation for each package is
given in the
Absolute Maximum Ratings
section under
Continuous Power Dissipation or can be calculated by
the following equation:
where T
J(MAX)
is +150
°
C, T
A
is the ambient tempera-
ture and
θ
JA
is the reciprocal of the derating factor in
°
C/W as specified in the
Absolute Maximum Ratings
section. For example,
θ
JA
of the μMAX package is
222
°
C/W.
P
T
T
DISSPK(
(
A
JA
)
)
=
θ
V
V
P
V
R
RMS
OUT P P
(
2 2
2
OUT
RMS
L
=
=
)
A
R
R
VD
F
IN
= ×
2
M
1.4W and 1W, Ultra-Small, Audio Power
Amplifiers with Shutdown
_______________________________________________________________________________________
9
+1
V
OUT(P-P)
2 x V
OUT(P-P)
V
OUT(P-P)
-1
Figure 1. Bridge-Tied Load Configuration
相關(guān)PDF資料
PDF描述
MAX4365 1.4W and 1W, Ultra-Small, Audio Power Amplifiers with Shutdown
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MAX4364ESA 1.4W and 1W, Ultra-Small, Audio Power Amplifiers with Shutdown
MAX4365ETA 1.4W and 1W, Ultra-Small, Audio Power Amplifiers with Shutdown
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相關(guān)代理商/技術(shù)參數(shù)
參數(shù)描述
MAX4365EGA 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX4365ETA 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX4365ETA+ 制造商:Rochester Electronics LLC 功能描述: 制造商:Maxim Integrated Products 功能描述:
MAX4365ETA+T 功能描述:音頻放大器 Integrated Circuits (ICs) 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
MAX4365ETA-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