SI270X-A-EVB Silicon Laboratories Inc, SI270X-A-EVB Datasheet - Page 27

• Manufacturer Part Number: SI270X-A-EVB
• Description: BOARD EVAL FOR SI270X-A
• Manufacturer: Silicon Laboratories Inc

Specifications of SI270X-A-EVB

• Board Type: Fully Populated
• Amplifier Type: Class D
• Output Type: 2-Channel (Stereo) with Stereo Headphones
• Max Output Power X Channels @ Load: 5W x 2 @ 3 Ohm
• Voltage - Supply: 9V
• Utilized Ic / Part: SI270X-A
• Description/function: Audio Amplifiers
• Output Power: 5 W
• Product: Audio Modules
• For Use With/related Products: Si270x
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Operating Temperature: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant
• Other names: 336-1929

4.6.1. Parametric Equalization (Si2706/07 only)
The Si2706/07 includes 16 fully programmable parametric equalizer filters. Seven of these filters are implemented
in each of the Left/Right main channels and the remaining two are used for the Aux Channel. The filters are
implemented using a biquad form and can be programmed to shape the frequency response of each channel
independently. The filters implement the configuration presented on Figure 21 which can be represented by the
following equation:
Where x[n] is the input sample and y[n] is the output sample.
The five coefficients for each biquad are programmed via the 2-Wire interface by using the command
SET_EQ_BIQUAD_FILTER_COEFF.
4.6.2. Tone Control
The Si270x implements tone control in the form of two second order shelving filters for bass and treble. Each filter
has programmable cut-off frequency and boost/cut gain. Cut-off frequency can be adjusted from 5 to 20 kHz by
setting properties BASS_CORNER_FREQ (for bass) and TREBLE_CORNER_FREQ (for treble). Gain can be
adjusted from –18 to +18 dB in 1 dB steps by setting properties BASS_BOOST_CUT (for bass) and
TREBLE_BOOST_CUT (for treble). Figure 22 shows the characteristics of the bass and treble shelving filters.
Figure 22. Generic Bass/Treble Shelving Filter Characteristics
Gain
1
Boost
Cut
y[n]=b0x[n]+b1x[n-1]+b2x[n-2]+a1y[n-1]+a2y[n-2];
Figure 21. Biquad Filter Configuration
-1
-1
Cutoff
Freq
Shelving Filter
0
BASS
1
2
Frequency
Rev. 0.6
Gain
1
Si2704/05/06/07-A10
1
2
Cutoff
Freq
-1
-1
Shelving Filter
TREBLE
Boost
Cut
Frequency
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