MAX9737EVKIT+ Maxim Integrated Products, MAX9737EVKIT+ Datasheet - Page 7

• Manufacturer Part Number: MAX9737EVKIT+
• Description: KIT EVAL FOR MAX9737
• Manufacturer: Maxim Integrated Products

Specifications of MAX9737EVKIT+

• Amplifier Type: Class D
• Output Type: 1-Channel (Mono)
• Max Output Power X Channels @ Load: 13W x 1 @ 4 Ohm
• Voltage - Supply: 8 V ~ 28 V
• Operating Temperature: -40°C ~ 85°C
• Board Type: Fully Populated
• Utilized Ic / Part: MAX9737
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX9737 filterless, mono class D audio power
amplifier offers Class AB audio performance and Class
D efficiency with minimal board space. The device
operates from an 8V to 28V supply range.
The MAX9737 features filterless, spread-spectrum
modulation, externally set gain and a low-power shut-
down mode that reduces supply current to less than
1µA. Comprehensive click-and-pop suppression and
precharge circuitry reduce noise into and out of shut-
down or mute within 10ms.
The MAX9737 features a unique spread-spectrum
switching modulation that flattens EMI wideband spec-
tral components, reducing radiated emissions from the
speaker and cables. The switching frequency of the
Class D amplifier varies randomly by ±4kHz around the
300kHz center frequency. Instead of a large amount of
spectral energy present at multiples of the switching
frequency, the energy is spread over a bandwidth that
increases with frequency. Above a few MHz, the wide-
band spectrum looks like white noise for EMI purposes.
1, 17, 18
3, 10, 11
13, 14
19, 20
21, 22
23, 24
PIN
12
15
16
—
2
4
5
6
7
8
9
CHOLD
NAME
AGND
SHDN
PGND
PVDD
MUTE
OUT+
COM
OUT-
REG
C1N
PRE
C1P
Spread-Spectrum Modulation
_______________________________________________________________________________________
PC
V
EP
IN
S
Detailed Description
Power Supply. Bypass PVDD to PGND with a 1µF capacitor connected to pin 1 and a 1µF capacitor
connected to pins 17 and 18.
Charge-Pump Output. Connect a 1µF capacitor to PVDD.
Analog Ground
Mute Input. Drive MUTE low to place the device in mute mode.
Shutdown Input. Drive SHDN low to place the part in shutdown mode.
Input Capacitor Precharge Connection. Connect between input resistor, R
capacitor, C
Op Amp Inverting Input.
Op Amp Output. PRE is the output of the input operational amplifier.
Internal 2.0V Bias. Bypass COM to AGND with a 1µF capacitor.
Internal 4.2V Bias. Bypass REG to AGND with a 1µF capacitor.
Internal 5.0V Bias. Bypass V
Charge-Pump, Flying-Capacitor Negative Terminal. Connect C1N to C1P through a 0.1µF capacitor.
Charge-Pump, Flying-Capacitor Positive Terminal. Connect C1P to C1N through a 0.1µF capacitor.
Negative Speaker Output
Power Ground
Positive Speaker Output
Exposed Pad. Must be externally connected to PGND.
IN
.
Mono 7W Class D Amplifier
S
to AGND with a 1µF capacitor.
A proprietary amplifier topology ensures this white
noise does not corrupt the noise floor in the audio
bandwidth.
The high efficiency of a Class D amplifier is due to the
output transistors acting as switches and therefore con-
sume negligible power. Power loss associated with the
Class D output stage is due to the MOSFET I
switching losses, and quiescent current.
Although the theoretical best efficiency of a linear
amplifier is 78% at peak output power, under typical
music reproduction levels, the efficiency falls to below
40%. The MAX9737 exhibits > 80% efficiency under the
same conditions (Figure 1).
The MAX9737 features a shutdown mode that reduces
power consumption to less than 1µA (typ), extending
battery life in portable applications. Drive SHDN low to
place the device in low-power shutdown mode. In shut-
down mode, the outputs are high impedance and the
common-mode voltage at the output decays to zero.
FUNCTION
IN
Pin Description
, and input coupling
Efficiency
Shutdown
2
R losses,
7