Instruction Manual
Table Of Contents
- Table of Contents
- List of Figures
- List of Tables
- 1. CDB4349 System Overview
- 2. CS4349 Digital-to-Analog Converter
- 3. CS8416 Digital Audio Receiver
- 4. Input for Clocks and Data
- 5. Input for Control Data
- 6. Power Supply Circuitry
- 7. Grounding and Power Supply Decoupling
- 8. Analog Output Filtering
- 9. Board Connections and Settings
- 10. Performance Plots
- Figure 1. FFT 0 dBFS, FS = 48 kHz
- Figure 2. FFT -60 dBFS, FS = 48 kHz
- Figure 3. FFT No Input, FS = 48 kHz
- Figure 4. FFT No Input Out of Band, FS = 48 kHz
- Figure 5. Frequency Response 0 dBFS, FS = 48 kHz
- Figure 6. THD+N vs Frequency 0 dBFS, FS = 48 kHz
- Figure 7. THD+N vs Level 1 kHz, FS = 48 kHz
- Figure 8. Fade-to-Noise Linearity 1 kHz, FS = 48 kHz
- Figure 9. Impulse Response, FS = 48 kHz
- Figure 10. FFT Crosstalk Ch. A to Ch. B 1 kHz, FS = 48 kHz
- Figure 11. FFT Crosstalk Ch. B to Ch. A 1 kHz, FS = 48 kHz
- Figure 12. FFT 0 dBFS, FS = 96 kHz
- Figure 13. FFT -60 dBFS, FS = 96 kHz
- Figure 14. FFT No Input, FS = 96 kHz
- Figure 15. FFT No Input Out of Band, FS = 96 kHz
- Figure 16. Frequency Response 0 dBFS, FS = 96 kHz
- Figure 17. THD+N vs Frequency 0 dBFS, FS = 96 kHz
- Figure 18. THD+N vs Level 1 kHz, FS = 96 kHz
- Figure 19. Fade-to-Noise Linearity 1 kHz, FS = 96 kHz
- Figure 20. Impulse Response, FS = 96 kHz
- Figure 21. FFT Crosstalk Ch. A to Ch. B 1 kHz, FS = 96 kHz
- Figure 22. FFT Crosstalk Ch. B to Ch. A 1 kHz, FS = 96 kHz
- Figure 23. FFT 0 dBFS, FS = 192 kHz
- Figure 24. FFT -60 dBFS, FS = 192 kHz
- Figure 25. FFT No Input, FS = 192 kHz
- Figure 26. FFT No Input Out of Band, FS = 192 kHz
- Figure 27. Frequency Response 0 dBFS, FS = 192 kHz
- Figure 28. THD+N vs Frequency 0 dBFS, FS = 192 kHz
- Figure 29. THD+N vs Level 1 kHz, FS = 192 kHz
- Figure 30. Fade-to-Noise Linearity 1 kHz, FS = 192 kHz
- Figure 31. Impulse Response, FS = 192 kHz
- Figure 32. FFT Crosstalk Ch. A to Ch. B 1 kHz, FS = 192 kHz
- Figure 33. FFT Crosstalk Ch. B to Ch. A 1 kHz, FS = 192 kHz
- 11. Schematics
- 12. Layout
- 13. Revision History
4 DS782DB1
CDB4349
1. CDB4349 SYSTEM OVERVIEW
The CDB4349 evaluation board is an excellent platform for quickly evaluating the CS4349. The CS8416 digital audio
interface receiver provides an easy interface to digital audio signal sources including the majority of digital audio test
equipment. The evaluation board also allows the user to supply external PCM clocks and data through headers for
system development.
The CDB4349 schematic has been partitioned into 6 pages, shown in Figures 35 through 40. Each schematic page
is represented in the system diagram shown in Figure 34. Notice that the system diagram also includes the inter-
connections between the partitioned schematics.
2. CS4349 DIGITAL-TO-ANALOG CONVERTER
A description of the CS4349 is included in the CS4349 datasheet, available at http://www.cirrus.com/en/prod-
ucts/pro/detail/P1116.html.
3. CS8416 DIGITAL AUDIO RECEIVER
The system receives and decodes the standard S/PDIF data format using a CS8416 digital audio receiver
(Figure 38). The outputs of the CS8416 include a serial bit clock, serial data, and a left-right clock. The CS8416 data
format is selected through switch S1. The operation of the CS8416 and a discussion of the digital audio interface is
included in the CS8416 datasheet, available at http://www.cirrus.com/en/products/pro/detail/P1005.html.
The CDB4349 has been designed so that the input can be either optical or coaxial (see Figure 39). However, both
inputs cannot be driven simultaneously.
After the CS8416 serial format is changed either through S1 in Stand-Alone Mode, or though the CDB4349 GUI in
PC Mode, a reset is required. The CS8416 can be manually reset using ‘HARDWARE RESET’ (S2) in Stand-Alone
Mode, or through software when operating the CDB4349 in PC Mode.
4. INPUT FOR CLOCKS AND DATA
The evaluation board has been designed to allow external PCM data input through header J10. The schematic for
the clock/data input is shown in Figure 37. In Stand-Alone Mode, switch position 6 of S4 selects the source as either
CS8416 (open) or header J10 (closed). In PC Mode, the PCM source is selected through software.
5. INPUT FOR CONTROL DATA
The evaluation board can be run in either a Stand-Alone Mode or with a PC. Stand-Alone Mode does not require
the use of a PC, and the mode pins are configured using switch positions 1 through 5 of S4 and switch positions 1
and 2 of S1. PC Mode uses software to set up the CS4349 through I²C
®
or SPI™ interface using the PC’s serial port
or USB port. When the serial port (RS232) or USB is attached and the CDB4349 software is running, PC Mode is
automatically selected.
Header J38 offers the option for external input of RST and SPI/I²C clocks and data. The board is set up from the
factory to use the on-board microcontroller in conjunction with software available at http://www.cirrus.com/en/prod-
ucts/software/msaudio.html. To use an external control source, remove the shunts on J38 and place a ribbon cable
so the signal lines are on the center row and the grounds are on the right side. R89 and R90 should be populated
with 2 kΩ resistors when using an external I²C source which does not already provide pull-ups.