MAX9736DETJ+T Maxim Integrated Products, MAX9736DETJ+T Datasheet - Page 15

• Manufacturer Part Number: MAX9736DETJ+T
• Description: IC AMP CLASS D HIGH PWR 32TQFN
• Manufacturer: Maxim Integrated Products
• Type: Class Dr

Specifications of MAX9736DETJ+T

• Output Type: 1-Channel (Mono) or 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 17mW x 1 @ 4 Ohm; 8.5mW x 2 @ 8 Ohm
• Voltage - Supply: 8 V ~ 28 V
• Features: Depop, 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 MAX9736 features comprehensive click-and-pop
suppression that minimizes audible transients on start-
up and shutdown. While in shutdown, the H-bridge is in
a high-impedance state.
The MAX9736 features a mono mode that allows the
right and left channels to operate in parallel, achieving
up to 30W (MAX9736A) of output power. Apply a logic-
high to MONO to enable mono mode. In mono mode,
an audio signal applied to the left channel (INL) is rout-
ed to the H-bridges of both channels. Also in mono
mode, the right-channel preamplifier becomes an
uncommitted operational amplifier, allowing for flexibili-
ty in system design. Connect OUTL+ to OUTR+ and
OUTL- to OUTR- using heavy PCB traces as close as
possible to the device. Driving MONO low (stereo
mode) while the outputs are wired together in mono
mode can trigger the short-circuit or thermal-overload
protection or both.
When the output current reaches the current limit, 4.6A
(typ), the MAX9736 disables the outputs and initiates a
450μs startup sequence. The shutdown and startup
sequence is repeated until the output fault is removed.
Properly designed applications do not enter current-
limit mode unless the output is short circuited or con-
nected incorrectly.
When the die temperature reaches the thermal shut-
down threshold, +160°C (typ), the MAX9736 outputs
are disabled. When the die temperature decreases by
30°C, normal operation resumes. Some causes of ther-
mal shutdown are excessively low load impedance,
poor thermal contact between the MAX9736‘s exposed
pad and the PCB, elevated ambient temperature, or
poor PCB layout and assembly.
The MAX9736 meets EN55022B EMC radiation limits
with an inexpensive ferrite bead and capacitor filter
when the speaker leads are less than or equal to 1m.
Select a ferrite bead with 100Ω to 600Ω impedance
and rated for at least 2A. The capacitor value varies
based on the ferrite bead chosen and the speaker lead
length. See Figure 3 for the correct connections of
these components.
Mono/Stereo High-Power Class D Amplifier
Applications Information
______________________________________________________________________________________
Filterless Class D Operation
Click-and-Pop Suppression
Mono Configuration
Thermal Shutdown
Current Limit
When evaluating the MAX9736 with a ferrite bead filter
and resistive load, include a series inductor (68μH for
8Ω load and 33μH for 4Ω load) to model the actual
loudspeaker’s behavior. Omitting the series inductor
Figure 4. Output Filter for PWM Mode
Figure 2. EMI Performance
Figure 3. Ferrite Bead Filter
FB1 AND FB2 = WURTH 742792040
40
35
30
25
20
15
10
5
30
MAX9736
MAX9736
100
200
300
EN55022B LIMIT
L1
L2
400
FREQUENCY (MHz)
FB1
FB2
500
C3
C1
600
C1
330pF
C2
700
R2
C5
800
R1
C4
C2
330pF
900
1000
15