LM49352RLX/NOPB National Semiconductor, LM49352RLX/NOPB Datasheet - Page 47

• Manufacturer Part Number: LM49352RLX/NOPB
• Description: IC AMP AUDIO MONO D1.4W 36USMD
• Manufacturer: National Semiconductor
• Series: Boomer®, PowerWise®r
• Type: Class Dr

Specifications of LM49352RLX/NOPB

• Output Type: 1-Channel (Mono) with Mono and Stereo Headphones
• Max Output Power X Channels @ Load: 1.4W x 1 @ 8 Ohm; 65mW x 2 @ 32 Ohm
• Features: Depop, Differential Inputs, I²C, I²S, Microphone, Shutdown, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 36-MicroSMDxt
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Supply: -
• Other names: LM49352RLX

Auxiliary Output Amplifier
The LM49352’s auxiliary output (AUXOUT) amplifier provides differential drive capability to loads that are connected across its
outputs. This results in output signals at the AUX_OUT+ and AUX_OUT- pins that are 180 degrees out of phase with respect to
each other. This effectively doubles the maximum possible output swing for a specific supply voltage when compared to single-
ended output configurations. The differential output configuration also allows the load to be isolated from ground since both the
AUX_OUT+ and AUX_OUT- pins are biased at the same DC potential. This eliminates the need for any large and expensive DC
blocking capacitors at the AUXOUT amplifier outputs. The load can then be directly connected to the positive and negative outputs
of the AUXOUT amplifier which then isolates it from any ground noise, thereby improving signal to noise ratio (SNR) and power
supply rejection ratio (PSRR).
The AUXOUT amplifier has two modes of operation. The primary mode of operation is high current drive mode (Earpiece Mode)
where the AUXOUT amplifier can be used to differentially drive a mono earpiece speaker. The secondary mode of operation is
low current drive mode where the AUXOUT amplifier operates in a power saving mode (AUX_LINE_OUT Mode) to provide a
differential output that is used as a mono differential line level input to a standalone mono differential input class D amplifier
(LM4675) for stereo loudspeaker applications.
Bits
3:1
7:6
0
4
5
AUX_LINE_OUT
AUX_NEG_6dB
LR_HP_LEVEL
LS_LEVEL
RSVD
Field
Reserved
This sets the gain of the left and right headphone amplifiers. The gain of the left and right headphone
amplifiers are always set to the same level.
This sets the gain of the Auxiliary output amplifier.
This sets the Auxiliary output amplifier mode of operation.
This sets the gain of the Class D loudspeaker amplifier.
TABLE 19. OUTPUT_OPTIONS (0x14h)
AUX_LINE_OUT
AUX_NEG_6dB
LR_HP_LEVEL
LS_LEVEL
000
001
010
011
100
101
110
111
00
01
10
11
0
1
0
1
47
Description
Auxiliary Output Mode
Earpiece Amplifier
AUX_LINE_OUT
Gain (dB)
Gain (dB)
Gain (dB)
–1.5
–12
–15
–18
–3
–6
–9
–6
12
0
0
0
4
8
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