User Manual
Table Of Contents
- 1. Pin Descriptions
- 2. Typical Connection Diagram
- 3. Characteristic and Specifications
- Recommended Operating Conditions
- Absolute Maximum Ratings
- Analog Input Characteristics
- ADC Digital Filter Characteristics
- Analog Output Characteristics
- Analog Passthrough Characteristics
- PWM Output Characteristics
- Headphone Output Power Characteristics
- Line Output Voltage Level Characteristics
- Combined DAC Interpolation and onChip Analog FIlter Response
- Switching Specifications - Serial Port
- Switching Specifications - I²C Control Port
- DC Electrical Characteristics
- Digital Interface Specifications and Characteristics
- Power Consumption
- 4. Applications
- 4.1 Overview
- 4.2 Analog Inputs
- 4.3 Analog Outputs
- 4.4 Analog In to Analog Out Passthrough
- 4.5 PWM Outputs
- 4.6 Serial Port Clocking
- 4.7 Digital Interface Formats
- 4.8 Initialization
- 4.9 Recommended Power-up Sequence
- 4.10 Recommended Power-Down Sequence
- 4.11 Required Initialization Settings
- 4.12 Control Port Operation
- 5. Register Quick Reference
- 6. Register Description
- 6.1 Chip I.D. and Revision Register (Address 01h) (Read Only)
- 6.2 Power Control 1 (Address 02h)
- 6.3 Power Control 2 (Address 03h)
- 6.4 Power Control 3 (Address 04h)
- 6.5 Clocking Control (Address 05h)
- 6.6 Interface Control 1 (Address 06h)
- 6.7 Interface Control 2 (Address 07h)
- 6.8 Input x Select: ADCA and PGAA (Address 08h), ADCB and PGAB (Address 09h)
- 6.9 Analog and HPF Control (Address 0Ah)
- 6.10 ADC HPF Corner Frequency (Address 0Bh)
- 6.11 Misc. ADC Control (Address 0Ch)
- 6.12 Playback Control 1 (Address 0Dh)
- 6.13 Miscellaneous Controls (Address 0Eh)
- 6.14 Playback Control 2 (Address 0Fh)
- 6.15 MICx Amp Control:MIC A (Address 10h) and MIC B (Address 11h)
- 6.16 PGAx Vol. and ALCx Transition Ctl.: ALC, PGA A (Address 12h) and ALC, PGA B (Address 13h)
- 6.17 Passthrough x Volume: PASSAVOL (Address 14h) and PASSBVOL (Address 15h)
- 6.18 ADCx Volume Control: ADCAVOL (Address 16h) and ADCBVOL (Address 17h)
- 6.19 ADCx Mixer Volume: ADCA (Address 18h) and ADCB (Address 19h)
- 6.20 PCMx Mixer Volume: PCMA (Address 1Ah) and PCMB (Address 1Bh)
- 6.21 Beep Frequency and On Time (Address 1Ch)
- 6.22 Beep Volume and Off Time (Address 1Dh)
- 6.23 Beep and Tone Configuration (Address 1Eh)
- 6.24 Tone Control (Address 1Fh)
- 6.25 Master Volume Control: MSTA (Address 20h) and MSTB (Address 21h)
- 6.26 Headphone Volume Control: HPA (Address 22h) and HPB (Address 23h)
- 6.27 Speaker Volume Control: SPKA (Address 24h) and SPKB (Address 25h)
- 6.28 ADC and PCM Channel Mixer (Address 26h)
- 6.29 Limiter Control 1, Min/Max Thresholds (Address 27h)
- 6.30 Limiter Control 2, Release Rate (Address 28h)
- 6.31 Limiter Attack Rate (Address 29h)
- 6.32 ALC Enable and Attack Rate (Address 2Ah)
- 6.33 ALC Release Rate (Address 2Bh)
- 6.34 ALC Threshold (Address 2Ch)
- 6.35 Noise Gate Control (Address 2Dh)
- 6.36 Status (Address 2Eh) (Read Only)
- 6.37 Battery Compensation (Address 2Fh)
- 6.38 VP Battery Level (Address 30h) (Read Only)
- 6.39 Speaker Status (Address 31h) (Read Only)
- 6.40 Charge Pump Frequency (Address 34h)
- 7. Analog Performance Plots
- 8. Example System Clock Frequencies
- 9. PCB Layout Considerations
- 10. ADC and DAC Digital Filters
- 11. Parameter Definitions
- 12. Package Dimensions
- 13. Ordering Information
- 14. References
- 15. Revision History
DS680F2 31
CS42L52
3/1/13
4.4 Analog In to Analog Out Passthrough
The CS42L52 accommodates analog routing of the analog input signal directly to the headphone amplifiers.
This feature is useful in applications that utilize an FM tuner where audio recovered over-the-air must be
transmitted to the headphone amplifier without digital conversion in the ADC and DAC. This analog
passthrough path reduces power consumption and is immune to modulator switching noise that could
interfere with some tuners.
4.4.1 Overriding the ADC Power Down
To accommodate automatic activation of the speaker amplifier when the SPK/HP_SW switch pin chang-
es, the CS42L52 provides the option to automatically power up the ADC whenever the analog signal must
route to the digital PWM modulator, regardless of the PDN_ADC bit. Refer to the table below for details
on how this ADC power-down override functions in accordance with the state of the speaker channels.
The shaded cells represent normal ADC operation when passthrough is disabled.
When PASSTHRU and PDN_OVRD are enabled, turning the speaker channel ON (by writing ‘11’b to SP-
Kx_PDN[1:0] or by automatic activation of the headphone detect switch, SPK/HP_SW) will automatically
disable the ADCx_PDN in order to convert the analog input to a digital signal for the PWM modulator. This
allows automatic analog input routing to the speaker amplifiers.
PDN_ADC PASSTHRU PDN_OVRD Speaker Channel ADC Status
0 x x x Powered UP
1
0 x x Powered DOWN
1
0xPowered DOWN
1
OFF Powered DOWN
ON Powered UP
MAX[2:0]
Output
(after Limiter)
Input
RRATE[5:0]ARATE[5:0]
Volume
Limiter
CUSH[2:0]
ATTACK/RELEASE SOUND
CUSHION
MAX[2:0]
Figure 14. Peak Detect and Limiter