MAX9706ETX+ Maxim Integrated Products, MAX9706ETX+ Datasheet - Page 15

• Manufacturer Part Number: MAX9706ETX+
• Description: IC AMP AUDIO 2.3W STER+1 36TQFN
• Manufacturer: Maxim Integrated Products
• Series: DirectDrive™r
• Type: Class Dr

Specifications of MAX9706ETX+

• Output Type: 2-Channel (Stereo) with Stereo Headphones and Subwoofer
• Max Output Power X Channels @ Load: 2.3W x 3 @ 4 Ohm; 95mW x 2 @ 16 Ohm
• Voltage - Supply: 4.5 V ~ 5.5 V
• Features: Depop, Short-Circuit and Thermal Protection, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 36-TQFN Exposed Pad
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The MAX9706/MAX9707 feature a unique spread-spec-
trum mode that flattens the wideband spectral compo-
nents, improving EMI emissions that can be radiated by
the speaker and cables. Enable SSM mode by setting
SYNC_IN = V
frequency varies randomly by ±50kHz around the cen-
ter frequency (1.15MHz). The modulation scheme
remains the same, but the period of the sawtooth wave-
form changes from cycle to cycle (Figure 3). Instead of
a large amount of spectral energy present at multiples
of the switching frequency, the energy is now spread
over a bandwidth that increases with frequency. Above
a few megahertz, the wideband spectrum looks like
white noise for EMI purposes. A proprietary amplifier
topology ensures this does not corrupt the noise floor in
the audio bandwidth.
Figure 3. Output with an Input Signal Applied (SSM Mode)
3-Channel, 2.3W, Filterless Class D Amplifiers
V
OUT_+
V
V
IN_+
IN_-
- V
DD
OUT_-
OUT_+
OUT_-
(Table 1). In SSM mode, the switching
______________________________________________________________________________________
Spread-Spectrum (SSM) Mode
t
ON(MIN)
t
SW
t
SW
Table 1. Operating Modes
GND
FLOAT
V
Clocked
with Active Crossover
DD
SYNC_IN
t
SW
FFM with f
FFM with f
SSM with f
FFM with f
t
SW
OSC
OSC
OSC
OSC
= 1100kHz
= 1340kHz
= external clock frequency
= 1150kHz ±50kHz
MODE
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