MAX9888EWY+T Maxim Integrated Products, MAX9888EWY+T Datasheet - Page 89

• Manufacturer Part Number: MAX9888EWY+T
• Description: IC CODEC AUDIO FLEXSOUND 63WLP
• Manufacturer: Maxim Integrated Products
• Series: DirectDrive®, FLEXSOUND™r
• Type: Class Dr

Specifications of MAX9888EWY+T

• Output Type: 3-Channel with Stereo Headphones
• Max Output Power X Channels @ Load: 1.37W x 2 @ 8 Ohm; 40mW x 2 @ 16 Ohm
• Voltage - Supply: 2.8 V ~ 5.5 V
• Features: Depop, Differential Inputs, I²S, Microphone, Mute, Shutdown
• Mounting Type: Surface Mount
• Package / Case: 63-WLP
• For Use With: MAX9888EVKIT+ - KIT EVALUATION FOR MAX9888
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

The IC integrates a stereo filterless Class D amplifier that
offers much higher efficiency than Class AB without the
typical disadvantages.
The high efficiency of a Class D amplifier is due to the
switching operation of the output stage transistors. In a
Class D amplifier, the output transistors act as current
steering switches and consume negligible additional
power. Any power loss associated with the Class D out-
put stage is mostly due to the I
on-resistance, and quiescent current overhead.
Figure 26. EMI with 15cm of Speaker Cable
Figure 27. Speaker Amplifier Path Block Diagram
-10
40
30
20
10
0
30
60
80
100
120
140
PGAOUT2:
0dB TO -23dB
PGAOUT3:
0dB TO -23dB
FREQUENCY (MHz)
160
PREOUT2
PREOUT3
Speaker Amplifiers
2
180
R loss of the MOSFET
200
DALEN
DAREN
DACL
DACR
+9dB
+9dB
220
240
with FLEXSOUND Technology
260
280
MIXSPL
MIXSPR
MIX
MIX
300
SPVOLL:
+8dB TO -62dB
SPVOLR:
+8dB TO -62dB
The theoretical best efficiency of a linear amplifier is
78%, however, that efficiency is only exhibited at peak
output power. Under normal operating levels (typical
music reproduction levels), efficiency falls below 30%,
whereas the IC’s Class D amplifier still exhibits 80% effi-
ciency under the same conditions.
Traditional Class D amplifiers require the use of exter-
nal LC filters or shielding to meet EN55022B and FCC
electromagnetic-interference (EMI) regulation standards.
Maxim’s patented active emissions limiting edge-rate
control circuitry reduces EMI emissions (Figure 26).
-10
40
30
20
10
0
300
Stereo Audio CODEC
350
BATTERY ADC
SPLEN
SPREN
+6dB
+6dB
POWER/DISTORTION LIMITER
400
450
500
550
FREQUENCY (MHz)
600
SPKRPGND
SPKLGND
SPKRVDD
SPKLVDD
650
SPKLN
SPKRP
SPKRN
SPKLP
700
750
800
850
900
950
1000
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