19-2862; Rev 2; 3/07
KIT
ATION
EVALU
E
BL
AVAILA
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
General Description
The MAX9765/MAX9766/MAX9767 family combines
speaker, headphone, and microphone amplifiers, all in
a small thin QFN package. The MAX9765 is targeted at
stereo speaker playback applications and includes a
stereo bridge-tied load (BTL) speaker amp, stereo
headphone amp, single-ended output mic amp, input
MUX, and I
2
C control. The MAX9766 is targeted at
mono speaker playback applications and includes a
mono BTL speaker amp, stereo headphone amp, differ-
ential output mic amp, input MUX, and I
2
C control. The
MAX9767 is targeted at applications that do not require
a headphone amp and includes a stereo BTL speaker
amp, differential output mic amp, and parallel control.
These devices operate from a single 2.7V to 5.5V supply.
A high 95dB PSRR allows these devices to operate from
noisy supplies without additional power conditioning. An
ultra-low 0.003% THD+N ensures clean, low distortion
amplification of the audio signal. Click-and-pop suppres-
sion eliminates audible transients on power and shut-
down cycles.
In speaker mode, the amplifiers can deliver up to
750mW of continuous average power into a 4Ω load. In
headphone mode, the amplifier can deliver up to 65mW
of continuous average power into a 16Ω load. The gain
of the amplifiers is externally set, allowing maximum
flexibility in optimizing output levels for a given load.
The MAX9765/MAX9766 also feature a 2:1 input multi-
plexer, allowing multiple audio sources to be selected.
The various functions are controlled by either an I
2
C-
compatible (MAX9765/MAX9766) or simple parallel
control interface (MAX9767).
All devices include two low-noise microphone pre-
amps, a differential amp for internal microphones, and
a single-ended amplifier for additional external micro-
phones. A microphone bias output is provided, reduc-
ing external component count.
The MAX9765/MAX9766/MAX9767 are available in a
thermally efficient 32-pin thin QFN package (5mm
✕
5mm
✕
0.8mm). All devices have short-circuit and
thermal-overload protection (OVP) and are specified
over the extended -40°C to +85°C temperature range.
♦
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Features
750mW BTL Stereo Speaker Amplifier
65mW Stereo Headphone Amplifier
2.7V to 5.5V Single-Supply Operation
Click-and-Pop Suppression
Low 0.003% THD+N
Low Quiescent Current: 13mA
Low-Power Shutdown Mode: 5µA
MUTE Function
Headphone Sense Input
Stereo 2:1 Input Multiplexer
Optional 2-Wire, I
2
C-Compatible, or Parallel
Interface
♦
Small 32-Pin Thin QFN (5mm
✕
5mm
✕
0.8mm)
Package
MAX9765/MAX9766/MAX9767
Ordering Information
PART
MAX9765ETJ
MAX9766ETJ
MAX9767ETJ
TEMP RANGE
-40
o
C to +85
o
C
-40
o
C to +85
o
C
-40
o
C to +85
o
C
PIN-
PACKAGE
32 TQFN-EP*
32 TQFN-EP*
32 TQFN-EP*
PKG
CODE
T3255-4
T3255-4
T3255-4
*EP
= Exposed paddle.
Pin Configurations and Functional Diagrams appear at end of data
sheet.
Simplified Diagram
MUX
INL1
INL2
MUX
INR1
INR2
SPKR
RIGHT
DEVICE
CONTROL
SPKR
LEFT
HEADPHONE
Applications
PDA Audio Systems
Tablet PCs
Cell Phones
Notebooks
Digital Cameras
CONTROL
MICIN-
MICIN+
AUXIN
MICBIAS
BIAS
MUX
MICOUT
MAX9765
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
MAX9765/MAX9766/MAX9767
ABSOLUTE MAXIMUM RATINGS
V
DD
to GND ...........................................................................+6V
SV
DD
to GND .........................................................................+6V
SV
DD
to V
DD
.........................................................................-0.3V
PV
DD
to V
DD
.......................................................................±0.3V
PGND to GND.....................................................................±0.3V
All Other Pins to GND.................................-0.3V to (V
DD
+ 0.3V)
Output Short-Circuit Duration (to V
DD
or GND)..........Continuous
Continuous Input Current (into any pin except power-supply
and output pins) ...............................................................±20mA
Continuous Power Dissipation (T
A
= +70°C)
32-Pin Thin QFN (derate 26.3mW/°C above +70°C) ...2105.3mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Junction Temperature ......................................................+150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
DD
= PV
DD
= 3.0V, GND = 0, HPS = MUTE = GND,
SHDN
= 3V, C
BIAS
= 1µF, R
IN
= R
F
= 15kΩ, R
L
=
∞.
T
A
= T
MIN
to T
MAX
, unless
otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Supply Voltage Range
Quiescent Supply Current
(I
VDD
+ I
PVDD
)
Shutdown Current
Switching Time
Turn-On/Turn-Off Time
Input Bias Current
Thermal Shutdown Threshold
Thermal Shutdown Hysteresis
Output Short-Circuit Current
STANDBY SUPPLY (SV
DD
)
Standby Current
I
SVDD
V
BIAS
= 1.25V, V
DD
= 0V
V
BIAS
= 1.5V, V
DD
= 3V
V
OUT_+
- V
OUT_-
, A
V
= 1V/V
V
DD
= 2.7V to 5.5V
f = 1kHz, V
RIPPLE
= 200mV
P-P
f
IN
= 1kHz, THD+N = 1%,
T
A
= +25
o
C (Note 2)
f
IN
= 1kHz, BW = 22Hz to
22kHz
R
L
= 8Ω
R
L
= 4Ω
P
OUT
= 200mW,
R
L
= 8Ω
P
OUT
= 400mW,
R
L
= 4Ω
400
72
10
85
72
450
750
0.033
%
0.065
89
dB
230
400
5
45
µA
To V
DD
or GND
SYMBOL
V
DD
/PV
DD
I
DD
I
SHDN
t
SW
t
ON/OFF
I
BIAS
CONDITIONS
Inferred from PSRR test
Speaker mode
MAX9765/MAX9767
MAX9766
MIN
2.7
12
7
7
5
10
250
25
50
150
8
1.2
TYP
MAX
5.5
28
17
17
18
µA
µs
ms
nA
o
o
UNITS
V
mA
Headphone mode, HPS = V
DD
SHDN
= GND
Gain or input switching
(MAX9765/MAX9766)
C
BIAS
= 1µF, settled to 90%
C
BIAS
= 0.1µF, settled to 90%
C
C
A
OUTPUT AMPLIFIERS (SPEAKER MODE)
Output Offset Voltage
Power-Supply Rejection Ratio
Output Power
V
OS
PSRR
P
OUT
mV
dB
mW
Total Harmonic Distortion Plus
Noise
THD+N
Signal-to-Noise Ratio
SNR
R
L
= 8Ω, V
OUT_
= 1.4V
RMS
, BW = 22Hz to
22kHz
2
_______________________________________________________________________________________
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= PV
DD
= 3.0V, GND = 0, HPS = MUTE = GND,
SHDN
= 3V, C
BIAS
= 1µF, R
IN
= R
F
= 15kΩ, R
L
=
∞.
T
A
= T
MIN
to T
MAX
, unless
otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Maximum Capacitive Load Drive
Slew Rate
Crosstalk
OUTPUT AMPLIFIERS (HEADPHONE MODE)
V
DD
= 2.7V to 5.5V
Power-Supply Rejection Ratio
PSRR
f = 1kHz, V
RIPPLE
= 200mV
P-P
f = 20kHz, V
RIPPLE
= 200mV
P-P
Output Power
P
OUT
f
IN
= 1kHz, THD+N = 1%,
T
A
= +25
o
C (Note 2)
R
L
= 32Ω
R
L
= 16Ω
V
OUT
= 0.7
RMS
,
R
L
= 10kΩ
Total Harmonic Distortion Plus
Noise
THD+N
f
IN
= 1kHz, BW = 22Hz to
22kHz
P
OUT
= 15mW,
R
L
= 32Ω
P
OUT
= 30mW,
R
L
= 16Ω
Signal-to-Noise Ratio
Slew Rate
Maximum Capacitive Load Drive
Crosstalk
BIAS VOLTAGE (BIAS)
BIAS Voltage
Output Resistance
V
BIAS
R
BIAS
V
DD
- V
OH
V
OL
- GND
V
DD
- V
OH
V
OL
- GND
1.4
1.5
50
35
50
80
70
0.6
10
50
2
31
11.6
0.01
300
100
5
70
400
150
400
V/µs
mA
pF
mV
nV/√Hz
%
kHz
kΩ
mV
1.6
V
kΩ
SNR
SR
C
L
No sustained oscillations
f
IN
= 10kHz
R
L
= 8Ω, V
OUT_
= 1.4V
RMS
,
BW = 20Hz to 22kHz
35
95
75
50
40
65
0.002
0.005
0.004
89
0.7
200
79
dB
V/µs
pF
dB
%
mW
dB
SYMBOL
C
L
SR
f
IN
= 10kHz
CONDITIONS
No sustained oscillations
MIN
TYP
400
1.4
73
MAX
UNITS
pF
V/µs
dB
MAX9765/MAX9766/MAX9767
MICROPHONE AMPLIFIER GENERAL
R
L
= 100kΩ
Output Voltage Swing
V
OUT
R
L
= 2kΩ
Slew Rate
Output Short-Circuit Current
Maximum Capacitive Load Drive
Input Offset Voltage
Input Noise-Voltage Density
Total Harmonic Distortion Plus
Noise
Small-Signal Bandwidth
Input Resistance
C
L
V
OS
e
N
THD+N
BW
-3dB
R
IN
f
IN
= 1kHz
A
V
= 20dB
A
V
= 40dB
SR
A
V
= 10dB
To V
DD
or GND
No sustained oscillations
DIFFERENTIAL INPUT AMPLIFIER (MICIN+, MICIN-)
V
DD
= 3V, V
OUT
= 0.35V
RMS,
A
V
= 10dB,
f
IN
= 1kHz, BW = 22Hz to 22kHz
A
V
= 40dB, V
OUT
= 100mV
P-P
MICIN_ to GND
_______________________________________________________________________________________
3
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
MAX9765/MAX9766/MAX9767
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= PV
DD
= 3.0V, GND = 0, HPS = MUTE = GND,
SHDN
= 3V, C
BIAS
= 1µF, R
IN
= R
F
= 15kΩ, R
L
=
∞.
T
A
= T
MIN
to T
MAX
, unless
otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
Input Resistance Matching
Differential Gain Accuracy
SYMBOL
R
MATCH
MAX9765, A
V
= 4dB to 39dB
A
VDIFF
MAX9766, A
V
= 10dB to 45dB
MAX9767, A
V
= 10dB, 20dB, 30dB
Common-Mode Rejection Ratio
CMRR
A
V
= 10dB, f
IN
= 1kHz, V
CM
= 200mV
P-P
,
R
S
= 2kΩ
V
DD
= 2.7V to 5.5V
Power-Supply Rejection Ratio
PSRR
A
V
= 10dB, output
referred
f = 1kHz, V
RIPPLE
=
200mV
P-P
f = 20kHz, V
RIPPLE
=
200mV
P-P
Common-Mode Input Voltage
Range
Input Offset Voltage
Input Noise-Voltage Density
Total Harmonic Distortion Plus
Noise
Small-Signal Bandwidth
Input Resistance
Voltage Gain Accuracy
V
CM
62
CONDITIONS
MIN
TYP
1
2
2
2
60
80
80
68
1
V
dB
4
4
4
dB
%
MAX
UNITS
%
SINGLE-ENDED INPUT AMPLIFIER (AUXIN)
V
OS
e
N
THD+N
BW
-3dB
R
IN
A
V
V
DD
= 2.7V to 5.5V
Power-Supply Rejection Ratio
PSRR
A
V
= 10dB, output
referred
f = 1kHz, V
RIPPLE
=
200mV
P-P
f = 20kHz, V
RIPPLE
=
200mV
P-P
MICROPHONE BIAS OUTPUT (MICBIAS)
Microphone Bias Output Voltage
Output Noise-Voltage Density
Power-Supply Rejection Ratio
V
MICBIAS
e
N
PSRR
V
DD
= 2.7V to 5.5V, I
LOAD
= 500µA
f = 1kHz
V
DD
= 2.7V to 5.5V
f
IN
= 1kHz, V
RIPPLE
= 200mV
P-P
2
0.8
±1
V
DD
GND
FLOAT
63
2.4
2.5
52
72
70
2.6
V
nV/√Hz
dB
65
A
V
= 20dB, f
IN
= 1kHz
A
V
= 10dB, f
IN
= 1kHz, BW = 22Hz to
22kHz, V
OUT
= 0.7V
RMS
A
V
= 20dB, V
OUT
= 100mV
P-P
4
73
0.01
200
100
4
80
76
58
dB
10
mV
nV/√Hz
%
kHz
kΩ
%
DIGITAL INPUTS (MUTE,
SHDN,
INT/EXT)
Input Voltage High
Input Voltage Low
Input Leakage Current
Input Voltage High
Input Voltage Low
Input Voltage Mid
V
IH
V
IL
I
IN
V
IH
V
IL
V
IZ
V
V
µA
V
V
V
MAX9767 MICGAIN INPUT (TRI-STATE PIN))
4
_______________________________________________________________________________________
750mW Audio Amplifiers with Headphone Amp,
Microphone Preamp, and Input Mux
ELECTRICAL CHARACTERISTICS (continued)
(V
DD
= PV
DD
= 3.0V, GND = 0, HPS = MUTE = GND,
SHDN
= 3V, C
BIAS
= 1µF, R
IN
= R
F
= 15kΩ, R
L
=
∞.
T
A
= T
MIN
to T
MAX
, unless
otherwise noted. Typical values are at T
A
= +25°C.) (Note 1)
PARAMETER
HEADPHONE SENSE INPUT (HPS)
Input Voltage High
Input Voltage Low
Input Leakage Current
V
IH
V
IL
I
IN
V
DD
> 3.6V
V
DD
≤
3.6V
3
2
0.8
0.2
I
IH
I
IL
C
IN
V
OL
I
OH
f
SCL
t
BUF
t
HD:STA
t
SU:STA
t
LOW
t
HIGH
t
SU:DAT
t
HD:DAT
t
R
t
F
t
F
t
SP
(Note 3)
(Note 4)
(Note 4)
(Note 4)
(Note 5)
1.3
0.6
0.6
1.3
0.6
100
0
20 +
0.1C
B
20 +
0.1C
B
20 +
0.1C
B
50
0.9
300
300
250
I
OL
= 3mA
V
OH
= 3V
V
IN
= 3V
V
IN
= 0V
10
0.4
1
400
±1
±1
0.9 x
V
DD
0.7 x
V
DD
±1
V
V
µA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX9765/MAX9766/MAX9767
2-WIRE SERIAL INTERFACE (SCL, SDA, ADD) (MAX9765/MAX9766)
Input Voltage High
Input Voltage Low
Input Hysteresis
Input High Leakage Current
Input Low Leakage Current
Input Capacitance
Output Voltage Low
Output Current High
Serial Clock Frequency
Bus Free Time Between STOP
and START Conditions
START Condition Hold Time
START Condition Setup Time
Clock Period Low
Clock Period High
Data Setup Time
Data Hold Time
Receive SCL/SDA Rise Time
Receive SCL/SDA Fall Time
Transmit SDA Fall Time
Pulse Width of Suppressed Spike
V
IH
V
IL
V
V
V
µA
µA
pF
V
µA
kHz
µs
µs
µs
µs
µs
ns
µs
ns
ns
ns
ns
TIMING CHARACTERISTICS (MAX9765/MAX9766)
All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
P
OUT
limits are tested by a combination of electrical and guaranteed by design.
A device must provide a hold time of at least 300ns for the SDA signal to bridge the undefined region of SCL’s falling edge.
C
B
= total capacitance of one of the bus lines in picofarads. Device tested with C
B
= 400pF. 1kΩ pullup resistors connected
from SDA/SCL to V
DD
.
Note 5:
Input filters on SDA, SCL, and ADD suppress noise spikes less than 50ns.
Note 1:
Note 2:
Note 3:
Note 4:
_______________________________________________________________________________________
5