19-3108; Rev 3; 9/09
KIT
ATION
EVALU
BLE
AVAILA
Mono/Stereo High-Power Class D Amplifier
MAX9736
General Description
The MAX9736A/B/D Class D amplifiers provide high-
performance, thermally efficient amplifier solutions. The
MAX9736A delivers 2 x 15W into 8Ω loads, or 1 x 30W
into a 4Ω load. The MAX9736B/D deliver 2 x 6W into 8Ω
loads or 1 x 12W into a 4Ω load.
These devices operate from 8V to 28V and provide a
high PSRR, eliminating the need for a regulated power
supply. The MAX9736 offers up to 88% efficiency at
12V supply.
Pin-selectable modulation schemes select between fil-
terless modulation and classic PWM modulation.
Filterless modulation allows the MAX9736 to pass CE
EMI limits with 1m cables using only a low-cost ferrite
bead and capacitor on each output. Classic PWM mod-
ulation is optimized for best audio performance when
using a full LC filter.
A pin-selectable stereo/mono mode allows stereo oper-
ation into 8Ω loads or mono operation into 4Ω loads. In
mono mode, the right input op amp becomes available
as a spare device, allowing flexibility in system design.
Comprehensive click-and-pop reduction circuitry mini-
mizes noise coming into and out of shutdown or mute.
Input op amps allow the user to create summing amplifiers,
lowpass or highpass filters, and select an optimal gain.
The MAX9736A/B/D are available in 32-pin TQFN pack-
ages and specified over the -40°C to +85°C tempera-
ture range.
Features
o
Wide 8V to 28V Supply Voltage Range
o
Spread-Spectrum Modulation Enables Low EMI
Solution
o
Passes CE EMI Limits with Low-Cost Ferrite
Bead/Capacitor Filter
o
Low BOM Cost
o
High 67dB PSRR at 1kHz Reduces Supply Cost
o
88% Efficiency Eliminates Heatsink
o
Thermal and Output Current Protection
o
< 1µA Shutdown Mode
o
Mute Function
o
Space-Saving, 32-Pin TQFN Packages, 7mm x
7mm x 0.8mm (MAX9736A/B), 5mm x 5mm x
0.8mm (MAX9736D)
Applications
LCD/PDP/CRT Monitors
LCD/PDP/CRT TVs
MP3 Docking Stations
Notebook PCs
PC Speakers
All-in-One PCs
Ordering Information
PART
MAX9736AETJ+
STEREO/MONO
OUTPUT POWER
2 x 15W/
1 x 30W
PIN-PACKAGE
32 TQFN-EP*
7mm x 7mm
Note:
All devices are specified over the -40°C to +85°C oper-
ating temperature range.
+Denotes
a lead(Pb)-free/RoHS-compliant package.
*EP
= Exposed pad.
Ordering Information continued at end of data sheet.
Simplified Diagram
8V TO 28V
8Ω
AUDIO
INPUTS
8Ω
INPUT RESISTORS AND
CAPACITORS SELECT GAIN
AND CUTOFF FREQUENCY
SHDN
MUTE
MONO
MAX9736
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
Mono/Stereo High-Power Class D Amplifier
MAX9736
ABSOLUTE MAXIMUM RATINGS
PVDD to PGND.......................................................-0.3V to +30V
AGND to PGND .....................................................-0.3V to +0.3V
INL, INR, FBL, FBR, COM to AGND .........-0.3V to (V
REG
+ 0.3V)
MUTE, SHDN,
MONO, MOD, REGEN to AGND.......-0.3V to +6V
REG to AGND ..............................................-0.3V to (VS + 0.3V)
VS to AGND (Note 1)................................................-0.3V to +6V
OUTL+, OUTL-, OUTR+,
OUTR-, to PGND...................................-0.3V to (PVDD + 0.3V)
C1N to PGND ..........................................-0.3V to (PVDD + 0.3V)
C1P to PGND ...........................(PVDD - 0.3V) to (V
BOOT
+ 0.3V)
BOOT to PGND ..............................(V
C1P
- 0.3V) to PVDD + 12V
OUTL+, OUTL-, OUTR+, OUTR-,
Short Circuit to PGND or PVDD...............................Continuous
Thermal Limits (Notes 2, 3)
Continuous Power Dissipation (T
A
= +70°C)
32-Pin TQFN 5mm x 5mm Multiple Layer PCB
(derate 34.5mW/°C above +70°C) ..................................2.76W
θ
JA
.................................................................................29°C/W
θ
JC
...................................................................................2°C/W
Continuous Power Dissipation (T
A
= +70°C)
32-Pin TQFN 7mm x 7mm Multiple Layer PCB
(derate 37mW/°C above +70°C) .....................................2.96W
θ
JA
.................................................................................27°C/W
θ
JC
...................................................................................1°C/W
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
Note 1:
VS cannot exceed PVDD + 0.3V. See the
Power Sequencing
section.
Note 2:
Thermal performance of this device is highly dependant on PCB layout. See the
Applications Information
section for more details.
Note 3:
Package thermal resistances were obtained using the method described in JEDEC specification JESD51-7, using a 4-layer
board. For detailed information on package thermal considerations, visit
www.maxim-ic.com/thermal-tutorial.
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
PVDD
= 20V, V
VS
= 5V, V
AGND
= V
PGND
= 0V, V
MOD
= V
SHDN
= V
MUTE
= 5V, REGEN = MONO = AGND, C1 = 0.1μF, C2 = 1μF,
R
IN
_ = 20kΩ and R
FB_
= 20kΩ, R
L
=
∞,
AC measurement bandwidth 22Hz to 22kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Notes 4, 5)
PARAMETER
Speaker Supply Voltage Range
Preamplifier Supply Voltage
Range
Undervoltage Lockout
SYMBOL
PVDD
VS
UVLO
I
PVDD
Quiescent Supply Current
I
VS
Shutdown Supply Current
REG Voltage
Preregulator Voltage
COM Voltage
Capacitive Drive
Output Swing (Note 6)
Open-Loop Gain
Input Offset Voltage
A
VO
V
OS
I
SHDN
V
REG
VS
V
COM
C
L
Sinking ±1mA
V
FB_
= V
COM
±500mV, R
FB_
= 20kΩ to IN_
Internal regulated 5V, V
REGEN
= 5V
1.9
R
L
=
∞,
V
REGEN
= 5V,
V
VS
= open
R
L
=
∞,
V
REGEN
= 0V,
V
VS
= 5V
V
SHDN
= 0V
T
A
= +25°C
T
A
= T
MIN
to T
MAX
T
A
= +25°C
T
A
= T
MIN
to T
MAX
I
PVDD
I
VS
4.2
4.8
2.05
30
±2
88
±1
2.2
1
14
CONDITIONS
Inferred from PSRR test
(Notes 1 and 7)
MIN
8
4.5
7
30
45
50
20
22
10
10
TYP
MAX
28
5.5
UNITS
V
V
V
mA
mA
μA
V
V
V
pF
V
dB
mV
AMPLIFIER DC CHARACTERISTICS
INPUT AMPLIFIER CHARACTERISTICS
2
_______________________________________________________________________________________
Mono/Stereo High-Power Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(V
PVDD
= 20V, V
VS
= 5V, V
AGND
= V
PGND
= 0V, V
MOD
= V
SHDN
= V
MUTE
= 5V, REGEN = MONO = AGND, C1 = 0.1μF, C2 = 1μF,
R
IN
_ = 20kΩ and R
FB_
= 20kΩ, R
L
=
∞,
AC measurement bandwidth 22Hz to 22kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Notes 4, 5)
PARAMETER
Input Amplifier Slew Rate
Input Amplifier Unity-Gain
Bandwidth
AMPLIFIER CHARACTERISTICS
Output Amplifier Gain (Note 8)
Output Current Limit
Output Offset
Power-Supply Rejection Ratio
V
OS
PSRR
OUT_+ to OUT_-, T
A
= +25°C
PVDD = 8V to 28V, T
A
= +25°C
f = 1kHz, 100mV
P-P
ripple
V
PVDD
= 12V
MAX9736A Output Power
(THD+N = 1%)
P
OUT_1%
Stereo
Mono
V
PVDD
= 18V
V
PVDD
= 24V
Stereo
Mono
Stereo
Mono
Stereo
Mono
MAX9736B Output Power
(THD+N = 1%)
P
OUT_1%
V
PVDD
= 18V
V
PVDD
= 24V
Stereo
Mono
Stereo
Mono
Stereo
Mono
MAX9736A Output Power
(THD+N = 10%)
P
OUT_10%
V
PVDD
= 18V
V
PVDD
= 24V
Stereo
Mono
Stereo
Mono
Stereo
Mono
MAX9736B Output Power
(THD+N = 10%)
P
OUT_10%
V
PVDD
= 18V
V
PVDD
= 24V
Stereo
Mono
Stereo
Mono
R
L
= 8Ω
R
L
= 4Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
65
A
V
MAX9736A, MAX9736D
MAX9736B
16.5
13.1
3.3
17
13.6
4.6
±2
80
67
8
13
15.5
13.5
27
13.5
27
6
11
12
6
12
6
12
10
16
19.5
17.5
35
17.5
35
7.5
14
15
7.5
15
7.5
15
W
W
W
W
±10
17.5
14.1
dB
A
mV
dB
SYMBOL
CONDITIONS
MIN
TYP
2.5
3.5
MAX
UNITS
V/μs
MHz
MAX9736
V
PVDD
= 12V
V
PVDD
= 12V
V
PVDD
= 12V
_______________________________________________________________________________________
3
Mono/Stereo High-Power Class D Amplifier
MAX9736
ELECTRICAL CHARACTERISTICS (continued)
(V
PVDD
= 20V, V
VS
= 5V, V
AGND
= V
PGND
= 0V, V
MOD
= V
SHDN
= V
MUTE
= 5V, REGEN = MONO = AGND, C1 = 0.1μF, C2 = 1μF,
R
IN
_ = 20kΩ and R
FB_
= 20kΩ, R
L
=
∞,
AC measurement bandwidth 22Hz to 22kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Notes 4, 5)
PARAMETER
SYMBOL
V
PVDD
= 12V
MAX9736D Output Power
(Thermally Limited)
V
PVDD
= 18V
V
PVDD
= 24V
CONDITIONS
Stereo
Mono
Stereo
Mono
Stereo
Mono
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
R
L
= 8Ω
R
L
= 4Ω
MIN
TYP
8.5
17
5.5
11
3.5
7
0.04
%
0.04
96.5
dB
97
120
100
100
88
36
dBV
Out of mute
270
36
300
±4
160
30
t
ON
110
330
kHz
kHz
°C
°C
ms
μV
RMS
dB
%
W
MAX
UNITS
Total Harmonic Distortion Plus
Noise
THD+N
MAX9736A, P
OUT
= 4W, f = 1kHz,
PWM modulation mode, R
L
= 8Ω
MAX9736B/D, P
OUT
= 2W, f = 1kHz,
PWM modulation mode, R
L
= 8Ω
MAX9736A/D,
P
OUT
= 8W, R
L
= 8Ω
MAX9736B, P
OUT
= 6W,
R
L
= 8Ω
Signal-to-Noise Ratio
SNR
A-weighted
Noise
Crosstalk
Efficiency
V
N
A-weighted
(Note 9)
MAX9736A/D
MAX9736B
L to R, R to L, P
OUT
= 1W, f = 1kHz, R
L
= 8Ω
η
P
OUT
= 8W, MAX9736A, PVDD = 12V, R
L
= 8Ω
Peak voltage, 32
samples/second,
A-weighted
(Notes 9 and 10)
Into mute
Click-and-Pop Level
K
CP
Switching Frequency
Spread-Spectrum Bandwidth
Thermal Shutdown Level
Thermal Shutdown Hysteresis
Turn-On Time
4
_______________________________________________________________________________________
Mono/Stereo High-Power Class D Amplifier
ELECTRICAL CHARACTERISTICS (continued)
(V
PVDD
= 20V, V
VS
= 5V, V
AGND
= V
PGND
= 0V, V
MOD
= V
SHDN
= V
MUTE
= 5V, REGEN = MONO = AGND, C1 = 0.1μF, C2 = 1μF,
R
IN
_ = 20kΩ and R
FB_
= 20kΩ, R
L
=
∞,
AC measurement bandwidth 22Hz to 22kHz, T
A
= T
MIN
to T
MAX
, unless otherwise noted.
Typical values are at T
A
= +25°C.) (Notes 4, 5)
PARAMETER
DIGITAL INTERFACE
Input Voltage High
Input Voltage Low
Input Voltage Hysteresis
Input Leakage Current
V
INH
V
INL
50
±10
2
0.8
V
V
mV
μA
SYMBOL
CONDITIONS
MIN
TYP
MAX
UNITS
MAX9736
Note 4:
All devices are 100% production tested at +25°C. All temperature limits are guaranteed by design.
Note 5:
Stereo mode (MONO = GND) specified with 8Ω resistive load in series with a 68μH inductive load connected across BTL
outputs. Mono mode (MONO = 5V) specified with a 4Ω resistive load in series with a 33μH inductive load connected
across BTL outputs.
Note 6:
Output swing is specified with respect to V
COM.
Note 7:
For typical applications, an external 5V supply is not required. Therefore, set REGEN = 5V. If thermal performance is a
concern, set REGEN = 0V and provide an external regulated 5V supply.
Note 8:
Output amplifier gain is defined as:
⎛
| (V
OUT_
+
)
−
(V
OUT _
−
) |
⎞
20
×
log
⎜
⎟
| V
FB _
|
⎝
⎠
Note 9:
Amplifier inputs AC-coupled to GND.
Note 10:
Specified at room temperature with an 8Ω resistive load in series with a 68μH inductive load connected across BTL outputs.
Mode transitions controlled by
SHDN
control pin.
_______________________________________________________________________________________
5