MAX4364ESA/V+T Maxim Integrated Products, MAX4364ESA/V+T Datasheet - Page 9

• Manufacturer Part Number: MAX4364ESA/V+T
• Description: IC AMP AUDIO PWR 1.4W MONO 8SOIC
• Manufacturer: Maxim Integrated Products
• Type: Class ABr

Specifications of MAX4364ESA/V+T

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 1.4W x 1 @ 8 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Depop, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX4364/MAX4365 bridged audio power ampli-
fiers can deliver 1.4W 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.
The MAX4364/MAX4365 feature an internally generated
common-mode bias voltage of V
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.
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.
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
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.
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
Applications Information
_______________________________________________________________________________________
CC
1.4W and 1W, Ultra-Small, Audio Power
or GND, the short-circuit protec-
Detailed Description
(MAX4364) or 1W into 8
Bridge-Tied Load
CC
/2 referenced to
Current Limit
Shutdown
BIAS
Amplifiers with Shutdown
the device is twice the closed-loop gain of the input
amplifier. The effective gain is given by:
Substituting 2
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.
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
ture and
°C/W as specified in the Absolute Maximum Ratings
section. For example,
222°C/W.
Figure 1. Bridge-Tied Load Configuration
J(MAX)
JA
P
DISSPKG MAX
is the reciprocal of the derating factor in
✕
is +150°C, T
V
+1
-1
P
OUT(P-P)
V
OUT
A
RMS
VD
(
2
JA
V
V
)
RMS
OUT P P
into the following equations
R
A
2 2
R
L
of the µMAX package is
T
R
IN
J MAX
F
is the ambient tempera-
2
(
(
Power Dissipation
JA
)
)
T
A
V
2 x V
V
OUT(P-P)
OUT(P-P)
OUT(P-P)
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