MAX9765ETJ MAXIM [Maxim Integrated Products], MAX9765ETJ Datasheet - Page 23

• Manufacturer Part Number: MAX9765ETJ
• Description: 750mW Audio Amplifiers with Headphone Amp, Microphone Preamp, and Input Mux
• Manufacturer: MAXIM [Maxim Integrated Products]

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Common-mode rejection ratio (CMRR) refers to an
amplifier’s ability to reject any signal applied equally to
both inputs. In the case of amplifying a low-level micro-
phone signal in noisy digital environments, CMRR is a
key figure of merit. In audio circuits, CMRR is given by:
where A
mode gain, ∆V
mode voltage (IN+ and IN- connected together), and
V
Typical input voltage magnitudes are small enough
such that the output is not clipped in either differential
or common-mode application. The MAX9765/MAX9766/
MAX9767 differential microphone amplifier architecture
CMRR actually improves as A
tional advantage to the use of differential inputs.
Table 7. Status Register Format
INDIFF
Improved PSRR.
Higher ground noise immunity.
Microphone and preamplifier can be placed physi-
cally farther apart, easing PC board layout require-
ments.
is the differential input voltage.
DM
BIT
750mW Audio Amplifiers with Headphone Amp,
7
6
5
4
3
2
1
0
REGISTER ADDRESS
is the differential gain, A
CMRR dB
INCM
______________________________________________________________________________________
(
is the change in input common-
Common-Mode Rejection Ratio
) =
A
A
AMPR+
AMPL+
DM
AMPR-
HPSTS
CM
NAME
AMPL-
THRM
X
X
DM
=
∆
V
INDIFF
V
increases—an addi-
Microphone Preamp, and Input Mux
INCM
CM
is the common-
Don’t Care
Don’t Care
VALUE
0
1
0
1
0
1
0
1
0
1
0
1
Under normal operating conditions, the MAX9765/
MAX9766/MAX9767 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 θ
°C/W as specified in the Absolute Maximum Ratings
Figure 8. Bridge-Tied Load Configuration
Device temperature below thermal limit
Device temperature exceeding thermal limit
OUTR- current below current limit
OUTR- current exceeding current limit
OUTR+ current below current limit
OUTR+ current exceeding current limit
OUTL- current below current limit
OUTL- current exceeding current limit
OUTL+ current below current limit
OUTL+ current exceeding current limit
Device in speaker mode
Device in headphone mode
—
—
J(MAX)
Power Dissipation and Heat Sinking
JA
P
DISSPKG MAX
0000 0000
is the reciprocal of the derating factor in
is +150°C, T
+1
-1
(
DESCRIPTION
)
=
A
T
J MAX
is the ambient tempera-
(
θ
JA
)
−
T
A
V
2 x V
V
OUT(P-P)
OUT(P-P)
OUT(P-P)
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