LM49350RLX/NOPB National Semiconductor, LM49350RLX/NOPB Datasheet - Page 60

• Manufacturer Part Number: LM49350RLX/NOPB
• Description: IC AUDIO SUBSYSTM .8W D 36USMDXT
• Manufacturer: National Semiconductor
• Series: Boomer®r
• Type: Class Dr

Specifications of LM49350RLX/NOPB

• Output Type: 1-Channel (Mono) with Mono and Stereo Headphones
• Max Output Power X Channels @ Load: 2W x 1 @ 4 Ohm; 69mW x 2 @ 32 Ohm
• Voltage - Supply: 2.7 V ~ 5.5 V
• Features: 3D, DAC, Depop, I²C, I²S, Mute, Short-Circuit and Thermal Protection, Shutdown, Volume Control
• Mounting Type: Surface Mount
• Package / Case: 36-MicroSMDxt
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: LM49350RLX

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25.0 Digital Effects Engine
25.1 DIGITAL SIGNAL PROCESSOR (DSP)
The LM49350 is designed to handle the entire audio signal
conditioning and processing within the audio system, thereby
freeing up the workload of any other applications processor
contained within the system. The LM49350 features two in-
dependent DSPs, one for the DAC and the other for the ADC.
Each DSP is fully featured and performs as a professional
The ADC and DAC DSP engines can be cascaded together
in any order via the digital mixer to combine different audio
effects to the same signal path. For example, a signal can be
processed with high-pass filtering from the ADC effects en-
gine with 3D stereo widening from the DAC effects engine.
Bits
Bits
0
1
2
3
4
0
1
2
3
4
ADC_SCLP_ENB
ADC_SCLP_ENB
ADC_HPF_ENB
ADC_ALC_ENB
DAC_ALC_ENB
ADC_EQ_ENB
DAC_EQ_ENB
ADC_PK_ENB
DAC_PK_ENB
DAC_3D_ENB
Field
Field
This enables the ADC's High Pass Filter.
This enables the ADC's Auto Level Control.
This enables the ADC's Peak Detector.
This enables the ADC's 5-band Parametric EQ.
This enables the ADC's Soft Clip Feature.
This enables the DAC's Auto Level Control.
This enables the DAC's Peak Detector.
This enables the DAC's 5-band Parametric EQ.
This enables the DAC's Stereo Widening Circuit.
This enables the DAC's Soft Clip Feature.
FIGURE 21. ADC DSP Effects Chain
FIGURE 22. DAC DSP Effects Chain
TABLE 45. ADC EFFECTS (0x70h)
TABLE 46. DAC EFFECTS (0x71h)
60
quality digital audio effects engine. The data paths on each
DSP engine are 24 bits wide for ultimate flexibility. Both DSP
engines feature digital volume control, automatic level control
(ALC), digital soft clip compression, and a 5-band parametric
EQ. The ADC DSP engine adds a dedicated high-pass filter
to reduce wind noise or pop noise during uplink. The DAC
DSP engine adds a digital 3D algorithm that allows for stereo
widening of the original audio signal. The effects chain of each
DSP engine is shown by the diagrams below.
The 5-band parametric EQs from each DSP engine can be
combined to form a single 10-band parametric EQ or a single
5-band parametric EQ with ±30dB (instead of ±15dB) gain
control for each band.
Description
Description
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