LM49352RLX/NOPB National Semiconductor, LM49352RLX/NOPB Datasheet - Page 56

• 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

22.0 Digital Mixer Control Registers
Digital Mixer
The LM49352’s digital mixer allows for flexible routing of digital audio signals between both audio ports, DAC, and ADC. This mixer
handles which digital data path (Port1 RX data, Port2 RX data, or ADC output) is routed to the DAC input. The digital mixer also
selects the appropriate digital data path (Port1 RX data, Port2 RX data, ADC output, or DAC DSP (Interpolator) output) that is used
for data transmission on Audio Port 1 and 2. Audio inputs to the digital mixer can be attenuated down to -18dB to avoid clipping
conditions. The digital mixer also allows direct routing from the DAC interpolator output to the ADC decimator input which allows
the DAC and ADC DSP blocks to be cascaded witjhout having to enable the analog of the DAC and ADC in order to save power.
Another key feature of the digital mixer is sample rate conversion (SRC) between audio ports. This allows simultaneous operation
of the dual audio ports even if each port is operating at a different sample rate. The LM49352 can be used as an audio port bridge
with SRC capability. The digital mixer allows either straight pass through between audio ports or, if desired, DSP effects can be
added to the digital audio signal during audio port bridge operation. The digital mixer automatically handles stereo I
2
S to mono
PCM conversion between audio ports and vice versa.
30072701
FIGURE 16. Digital Mixer
The LM49352 includes two separate and independent DSP blocks, one for the DAC and the other for the ADC. The digital mixer
also allows both DSP blocks to be cascaded together in either order so that the DSP effects from both blocks can be combined
into the same signal path. For example, the 5 band parametric EQ of each DSP block can be combined together to form a 10 band
parametric EQ for added flexibility.
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