MAX9759ETE+ Maxim Integrated Products, MAX9759ETE+ Datasheet - Page 16

• Manufacturer Part Number: MAX9759ETE+
• Description: IC AMP AUDIO PWR 3.2W D 16TQFN
• Manufacturer: Maxim Integrated Products
• Type: Class Dr

Specifications of MAX9759ETE+

• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 4.3W x 1 @ 3 Ohm
• Voltage - Supply: 3 V ~ 5.5 V
• Features: Depop, Differential Inputs, Mute, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 16-TQFN Exposed Pad
• Product: Class-D
• Output Power: 3.2 W
• Common Mode Rejection Ratio (min): 67 dB
• Thd Plus Noise: 0.03 %
• Operating Supply Voltage: 3 V to 5.5 V
• Supply Current: 8.4 mA
• Maximum Power Dissipation: 1.8 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Supply Voltage (max): 5.5 V
• Supply Voltage (min): 3 V
• Amplifier Class: D
• No. Of Channels: 1
• Supply Voltage Range: 3V To 5.5V
• Load Impedance: 4ohm
• Operating Temperature Range: -40°C To +85°C
• Amplifier Case Style: TQFN
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

3.2W, High-Efficiency, Low-EMI,
Filterless, Class D Audio Amplifier
The MAX9759 does not require an output filter for the
short speaker cable. The device passes FCC emissions
standards with 7.6cm of unshielded speaker cables.
However, output filtering can be used if a design is fail-
ing radiated emissions due to board layout, cable
length, or the circuit’s close proximity to EMI-sensitive
devices. Use an LC filter when radiated emissions are a
concern, or when long leads are used to connect the
amplifier to the speaker.
Proper power-supply bypassing ensures low-distortion
operation. For optimum performance, bypass V
GND and PV
tors as close to each pin as possible. A low-imped-
ance, high-current, power-supply connection to PV
is assumed. Additional bulk capacitance should be
added as required depending on the application and
power-supply characteristics. GND and PGND should
be star-connected to system ground.
Figure 10. Single-Ended Drive of MAX9759 Plus Volume
Control
16
Supply Bypassing, Layout, and Grounding
______________________________________________________________________________________
DD
1µF
1µF
to PGND with separate 0.1µF capaci-
22kΩ
22kΩ
50kΩ
CW
IN-
IN+
MAX9759
Output Filter
DD
DD
to
Use wide, low-resistance output traces. As load imped-
ance decreases, the current drawn from the device out-
puts increase. At higher current, the resistance of the
output traces decrease the power delivered to the load.
Wide output, supply, and GND traces also improve the
power dissipation of the device.
The MAX9759 thin QFN package features an exposed
thermal pad on its underside. This pad lowers the
package’s thermal resistance by providing a direct
heat conduction path. Due to the high efficiency of the
MAX9759’s Class D Amplifier, an external heatsink is
not required. For optimum thermal performance, con-
nect the exposed paddle to GND.
Two MAX9759s can be configured as a stereo amplifier
(Figure 7). Device U1 is the master amplifier; its oscilla-
tor output, SYNC_OUT, drives the SYNC input of the
slave device (U2), synchronizing the switching frequen-
cies of the two devices. Synchronizing two MAX9759s
ensures that no beat frequencies within the audio spec-
trum occur on the power-supply rails. This stereo con-
figuration works when the master device is in either
FFM or SSM mode. There is excellent THD+N perfor-
mance and minimal crosstalk between devices due to
the SYNC and SYNC_OUT connection (Figures 8, 9).
Multiple MAX9759s can be cascaded and frequency
locked in a similar fashion (Figure 7). Repeat the stereo
configuration outlined in Figure 7 for multiple cascading
amplifier applications.
If volume control is required, connect a potentiometer
between the differential inputs of the MAX9759, as seen
in Figure 10. In this configuration, each input “sees”
identical RC paths when the device is powered up. The
variable resistive element appears between the two
inputs, meaning the setting affects both inputs the same
way. This configuration significantly improves transient
performance on power-up or release from SHDN.
Stereo Configuration
Volume Control