MAX9759ETE+ Maxim Integrated Products, MAX9759ETE+ Datasheet - Page 13

• 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

sent at the input of the MAX9759, the outputs switch as
shown in Figure 4. Because the MAX9759 drives the
speaker differentially, the two outputs cancel each other,
resulting in no net Idle Mode™ voltage across the
speaker and minimal power consumption.
Efficiency of a Class D amplifier is mostly associated
with the region of operation of the output stage transis-
tors. In a Class D amplifier, the output transistors act as
current-steering switches and consume negligible addi-
tional power. Any power loss associated with the Class
D output stage is mostly due to the I x R loss of the
MOSFET on-resistance and quiescent current overhead.
The theoretical best efficiency of a linear amplifier is
78%; however, that efficiency is only exhibited at peak
output powers. Under normal operating levels (i.e., typi-
cal music reproduction levels), efficiency of a linear
amplifier can fall below 30%. The MAX9759 Class D
amplifier still exhibits >90% efficiencies under the same
conditions (Figure 5).
The MAX9759 features an internally set, logic-selec-
table gain. The G1 and G2 logic inputs set the gain of
the MAX9759 speaker amplifier (Table 2).
The MAX9759 features a shutdown mode that reduces
power consumption and extends battery life. Driving
SHDN low places the MAX9759 in a low-power (0.1µA)
shutdown mode. Drive SHDN high for normal operation.
Figure 3. MAX9759 EMI Spectrum
Idle Mode is a trademark of Maxim Integrated Products, Inc.
50
45
40
35
30
25
20
15
30
60
3.2W, High Efficiency, Low-EMI, Filterless,
80
100
______________________________________________________________________________________
120
140
FCC LIMIT
FREQUENCY (MHz)
OUTPUT SPECTRUM
160
MAX9759
180
200
Gain Selection
220
240
Efficiency
Shutdown
260
280
300
Class D Audio Amplifier
Figure 4. MAX9759 Outputs with No Input Signal
Figure 5. MAX9759 Efficiency vs. Output Power
Table 2. Gain Selection
V OUT+ - V OUT- = 0V
V IN = 0V
G2
0
0
1
1
OUT+
OUT-
100
90
80
70
60
50
40
30
20
10
0
0
EFFICIENCY vs. OUTPUT POWER
0.2
0.4
OUTPUT POWER (W)
MAX9759
G1
0
1
0
1
0.6
0.8
CLASS AB
1.0
V
f = 1kHz
R
DD
L
= 8Ω
= 5V
GAIN (dB)
1.2
+24
+18
+12
+6
13