CRD4525-Q1 Cirrus Logic Inc, CRD4525-Q1 Datasheet - Page 34

• 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

34
6.1.4.7
The CS4525 includes adaptive loudness compensation to enhance the audibility of program material at
low volume levels. The adaptive loudness compensation feature operates by varying the bass and treble
boost of the tone control shelving filters as the volume level changes.
The level of boost added to the shelving filters is determined by the average of the effective volume set-
tings of channels A and B after the master volume control. As this average volume setting decreases from
0 dB, the boost of the bass and treble shelving filters is gradually increased until it reaches the maximum
boost level of 12.0 dB. As the volume is increased, the boost applied due to the adaptive loudness com-
pensation feature will be gradually removed until it reaches the level specified by the Treble[3:0] and
Bass[3:0] bits in the Tone Control register.
The adaptive loudness compensation feature is enabled by setting the Loudness bit in the Tone Config
register. When the loudness feature is enabled, it immediately evaluates the effective average volume and
applies bass and treble boost accordingly. When disabled, any treble or bass boost applied due to the
loudness feature will be removed.
Because the adaptive loudness compensation filter operates by adjusting the boost level of the tone con-
trol shelving filters, it is necessary that they be enabled with the EnToneCtrl bit in the Tone Config register
in order for the loudness feature to be operational. If the tone control filters are disabled, the adaptive loud-
ness compensation feature will not be functional.
Referenced Control
Loudness.............................
EnToneCtrl ..........................
TrebFc[1:0] ..........................
BassFc[1:0] .........................
Treble[3:0] ...........................
Bass[3:0] .............................
Adaptive Loudness Compensation
Register Location
“Adaptive Loudness Compensation Control (Loudness)” on page 76
“Tone Control Enable (EnToneCtrl)” on page 77
“Treble Corner Frequency (TrebFc[1:0])” on page 77
“Bass Corner Frequency (BassFc[1:0])” on page 77
“Treble Gain Level (Treb[3:0])” on page 78
“Bass Gain Level (Bass[3:0])” on page 78
CS4525
DS726PP3