CRD4525-Q1 Cirrus Logic Inc, CRD4525-Q1 Datasheet - Page 42

• Manufacturer Part Number: CRD4525-Q1
• Description: REFERENCE BOARD FOR CS4525 PWM
• Manufacturer: Cirrus Logic Inc
• Series: Popguard®r

Specifications of CRD4525-Q1

• Amplifier Type: Class D
• Output Type: 2-Channel (Stereo)
• Max Output Power X Channels @ Load: 15W x 2 @ 8 Ohm
• Voltage - Supply: 12 V ~ 18 V
• Operating Temperature: 0°C ~ 70°C
• Board Type: Fully Populated
• Utilized Ic / Part: CS4525
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: 598-1586

42
6.1.4.13 2-Way Crossover & Sensitivity Control
The CS4525 implements a dedicated stereo 24 dB/octave Linkwitz-Riley crossover filter with adjustable
cross-over frequency and sensitivity control to facilitate 2-way speaker configurations. The filter’s high-
pass output can be used to drive the tweeter, and its low-pass output can be used to drive the mid-
range/woofer. The sensitivity control is included to adjust the level of the high-pass and low-pass outputs
to compensate for differences in the tweeter and mid-range/woofer sensitivity.
The two-way crossover is implemented with one of two preset internal filter sets. One set is optimized for
a 32 kHz sample rate, and the other is optimized for 44.1 kHz, 48 kHz, and 96 kHz sample rates. The
CS4525 automatically detects the input sample rate and chooses the appropriate filter set to apply. The
available cross-over frequencies are shown in
bits in the Volume Cfg register.
Note that the corner frequency of each filter set scales linearly with the input sample rate.
When the internal ADC is used as the serial audio data source, the input sample rate is nominally 48 kHz
and the corresponding shelving frequency corners are available.
The sensitivity level of the high- and low-pass outputs of the crossovers can be independently adjusted
from 0 dB to -7.5 dB in 0.5 dB increments. The maximum attenuation level of -7.5 dB will compensate for
an approximate 4 dB difference in sound pressure level (SPL) between the tweeter and the mid-
range/woofer drivers. The sensitivity is adjusted using the HighPass[3:0] and LowPass[3:0] bits in the
Sensitivity register. Note that these bits affect the sensitivity of both channel A and channel B high- and
low-pass outputs.
The 2-way crossover can be enabled by setting the En2Way bit in the Volume Cfg register.
Referenced Control
En2Way...............................
2WayFreq[2:0].....................
HighPass[3:0]......................
LowPass[3:0].......................
X-Over Freq 0
X-Over Freq 1
X-Over Freq 2
X-Over Freq 3
X-Over Freq 4
X-Over Freq 5
X-Over Freq 6
X-Over Freq 7
Register Location
“Enable 2-Way Crossover (En2Way)” on page 81
“2-Way Cross-Over Frequency (2WayFreq[2:0])” on page 81
“Channel A and Channel B High-Pass Sensitivity Adjust (HighPass[3:0])” on page 82
“Channel A and Channel B Low-Pass Sensitivity Adjust (LowPass[3:0])” on page 81
Table 5. 2-Way Cross-Over Frequencies
2.0 kHz
2.2 kHz
2.4 kHz
2.6 kHz
2.8 kHz
3.0 kHz
3.2 kHz
3.4 kHz
32 kHz
Table 5
below and are configured with the 2WayFreq[2:0]
Input Sample Rate
44.1 kHz
1.92 kHz
2.11 kHz
2.30 kHz
2.49 kHz
2.68 kHz
2.88 kHz
3.07 kHz
3.26 kHz
48 kHz, 96 kHz
2.09 kHz
2.30 kHz
2.50 kHz
2.71 kHz
2.92 kHz
3.13 kHz
3.34 kHz
3.55 kHz
CS4525
DS726PP3