MAX9766ETJ+T Maxim Integrated Products, MAX9766ETJ+T Datasheet - Page 16

• Manufacturer Part Number: MAX9766ETJ+T
• Description: IC AMP AUDIO .75W MONO AB 32TQFN
• Manufacturer: Maxim Integrated Products
• Type: Class ABr

Specifications of MAX9766ETJ+T

• Output Type: 1-Channel (Mono) with Stereo Headphones
• Max Output Power X Channels @ Load: 750mW x 1 @ 4 Ohm; 65mW x 2 @ 16 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: Depop, I²C, Input Multiplexer, Microphone, Mute, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX9765/MAX9766/MAX9767 feature 750mW BTL
speaker amplifiers, 65mW headphone amplifiers, input
multiplexers, headphone sensing, differential and sin-
gle-ended input microphone amplifiers, and compre-
hensive click-and-pop suppression. The MAX9765/
MAX9766 are controlled through an I
wire serial interface. The MAX9767 is controlled
through three logic inputs: MUTE, SHDN, INT (see the
Selector Guide). The MAX9765 family features excep-
tional PSRR (95dB at 1kHz), allowing these devices to
operate from noisy digital supplies without the need for
a linear regulator.
The speaker amplifiers use a BTL configuration. The
MAX9765/MAX9766 main amplifiers are composed of
an input amplifier and an output amplifier. Resistor R
sets the input amplifier’s gain, and resistor R
output amplifier’s gain. The output of these two ampli-
fiers serves as the input to a slave amplifier configured
as an inverting unity-gain follower. This results in two
outputs, identical in magnitude, but 180
The overall gain of the speaker amplifiers is twice the
product of the two amplifier gains (see the Gain-Setting
Resistor section). A unique feature of this architecture
is that there is no phase inversion from input to output.
The MAX9767 does not use a two-stage input amplifier
and therefore has phase inversion from input to output.
When configured as a headphone (single-ended) ampli-
fier, the slave amplifier is disabled, muting the speaker
and the main amplifier drives the headphone. The
MAX9765/MAX9766/MAX9767 can deliver 700mW of
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
16
M A X9 7 6 5
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M A X9 7 6 6
PIN
19
23
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Detailed Description
M A X9 7 6 7
17
25
26
28
30
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9
MICOUT-
MICGAIN
INT/EXT
GAINM
2
NAME
MUTE
C-compatible, 2-
INR
INL
EP
°
out of phase.
F
sets the
Microphone Amplifier Negative Output
Mono Mode Gain Set
Left-Channel Input
Internal (Differential) or External (Single-Ended) Input Select. Drive INT/EXT
low to select internal or high to select external microphone amplifier.
Microphone Amplifier Gain Set. Tri-State Pin. Connect to V
float for gain = 20dB, and to GND for gain = 30dB.
Right-Channel Input
Mute Input
Exposed Pad. Connect to ground plane of PC board to optimize heatsinking.
IN
continuous average power into a 4Ω load with less than
1% THD+N in speaker mode. The MAX9765/MAX9766
can deliver 70mW of continuous average power into a
16Ω load with less than 1% THD+N in headphone
mode. The speaker amplifiers also feature thermal-
overload and short-circuit current protection.
All devices feature microphone amplifiers with both dif-
ferential and single-ended inputs. Differential input is
intended for use with internal microphones. Single-
ended input is intended for use with external (auxiliary)
microphones. The differential input configuration is par-
ticularly effective when layout constraints force the
microphone amplifier to be physically remote from the
ECM microphone and/or the rest of the audio circuitry.
The MAX9766/MAX9767 feature a complementary out-
put, creating an ideal interface with CODECs and other
devices with differential inputs. All devices also feature
an internal microphone bias generator.
These devices feature an internally generated com-
mon-mode bias voltage of 1.5V referenced to GND.
BIAS provides both click-and-pop suppression and
sets the DC bias level for the audio signal. BIAS is inter-
nally connected to the noninverting input of each
speaker amplifier (see the Typical Application Circuit).
Choose the value of the bypass capacitor as described
in the BIAS Capacitor section.
The MAX9765/MAX9766 feature a 2:1 input multiplexer
on the front end of each amplifier. The multiplexer is
controlled by bit 1 in the control register. A logic low
Pin Description (continued)
FUNCTION
Amplifier Common-Mode Bias
Input Multiplexer
DD
for gain = 10dB,