1. 1 www.quickfiltertech.com Audio-Mojo Application-Specific Development Board for Audio Applications using the QF1D512 April 2007 www.quickfiltertech.com

2. 2 www.quickfiltertech.com Audio-Mojo SavFIRe TM Audio Reference Design Demonstrates equalization and crossover functionality 2 QF1D512s, stereo codec, uC/EE Use standalone, or, Plugs into QF1D512-DK Dev Kit Preconfigured for use as 2-channel EQ or 1 channel crossover Design/modify filters using Quickfilter Pro Software Verify filter response on DK Download to Audio-Mojo Use standalone with new settings Audio-Mojo Board Audio-Mojo mounted on QF1D512-DK

3. 3 www.quickfiltertech.com Audio Mojo Overview Demonstrate QF capability for audio As an equalizer As a crossover Proof of concept / reference design Schematics and software available Development Tool User can experiment with his own filter designs Can save his config to the board and then... Standalone operation User can implement in his system without dev kit

4. 4 www.quickfiltertech.com Audio-Mojo Block Diagram Analog In ADC I2S STEREO CODEC CS4270 DAC I2S Analog Out QF1D512 f f L L R R uC* ATtiny85 Config Programming header GND Header To QF1D512-DK (optional) To Atmel programmer or QF1D512-DK (optional) Header Ext. Pwr * uC used for configuration only using stored settings / filters in on-chip EEPROM Not used in the signal data path

5. 5 www.quickfiltertech.com Audio Mojo Audio Inputs Audio Outputs Programming Header Ext Power Codec Config Signal Routing QF1D512s uCCodec

6. 6 www.quickfiltertech.com Configuration Example 1 Equalizer Each filter processes data from only one channel Use LRCK signal from codec to frame channels Independent filtering per channel. Analog In Codec L-Ch R-Ch QF1D512 f f LeftRight Analog Out L-Ch R-Ch DK Monitor L-ChR-ChL-Ch’R-ChL-Ch’R-Ch’ Output from codecOutput from 1 st QF1D512Output from 2 nd QF1D512 LRCK

7. 7 www.quickfiltertech.com Configuration Example 2 Crossover Both channels fed with same signal HPF on Left channel, LPF on right channel Analog outputs become high frequency content (L) and low frequency content (R) Can also be combined with equalization Analog In Codec L-Ch R-Ch Left / HighRight / Low Analog Out High Low DK Monitor QF1D512 f f

8. 8 www.quickfiltertech.com Standalone Mode User provides power source uC loads QF1D512 SavFIRes on power up User can input analog data and monitor analog outputs Development Connect to Atmel programmer via topside header (J3) Use QF Pro to design and save Config data Import Configs to Dev Tool & download configs to uC Standalone Use

9. 9 www.quickfiltertech.com Monitor Mode Uses QF1D512 SavFIRes on Audio-Mojo board uC loads SavFIRes at power up with default settings User applies analog inputs and monitor analog outputs Display FFT of frequency response (Monitor mode) No filter thumbnails / Edit disabled Dev Kit Mode Uses QF1D512 SavFIRes on dev board QF Pro software can be used to modify filter responses Support “near real time” adjustment of filter parameters e.g. Graphic EQ User can apply analog inputs and monitor analog outputs Download configs to Audio-Mojo board for standalone use Use with Development Kit

10. 10 www.quickfiltertech.com Runs out of the box, no cables or other hardware to make Modify and see results of filter changes in “near real time” with no need for a new build each time View FFTs of actual end hardware performance, not just theoretical results Advantages of use with Dev Kit

11. 11 www.quickfiltertech.com Logarithmic Filter Response Option Graphic Filter Editor QF Pro Software Upgrades Simultaneous capture & display of two channels

12. 12 www.quickfiltertech.com Atmel programmer Export hex files from QF Pro for download to ATtiny QF Dev Kit Connect programming header to J4 Download configs directly to the ATtiny from the QF Pro software Note: Tiny memory is partitioned to simplify the task: Program memory (user need not alter!) SavFIRe configs (4) = 2 complete 2-channel configs Programming Options

13. 13 www.quickfiltertech.com QF1D512 Applications Ideas

14. 14 www.quickfiltertech.com QF1D512 Host uC ADC QF1D512 Host uC ADC External ADC or codec Internal ADC / Coprocessor Audio Applications Flexible Interface Options

15. 15 www.quickfiltertech.com Audio Applications Flexible Interface Options - 2 Accepts serial digital data SPI or I2S directly S/P-DIF after conversion Precision filtering without dedicated computing resource System uC can load config / filter data QF1D512 Converter e.g.CS8420 Analog In ADC I2S, SPI S/P-DIF Digital In Digital Filtered Data Out SPI

16. 16 www.quickfiltertech.com Audio Application: Stereo / Multi-channel Filtering Each filter processes data from only one ADC input. Independent filtering per channel. Add as many chips as needed for channel count. QF1D512 Ch1 Filter Analog In ADC QF1D512 Ch2 Filter Ch1 Ch2 Digital Out e.g. CS53xx

17. 17 www.quickfiltertech.com Audio Application Equalizer Use single device with optimized ”shape” for the whole band Use Number of Taps to implement variable delay Cascade multiple chips in series Dedicate each device to a particular frequency band Not suitable for applications where latency is an issue! QF1D512 f0f0 f2f2 f1f1 f Data In Filtered Data Out Data In Filtered Data Out f f f

18. 18 www.quickfiltertech.com Audio Application Digital Wireless Headphones - 1 QF1D512 filters out any unwanted noise, shapes frequency response to suit headphone driver & enclosure DAC only if digital data transmitted, codec otherwise Analog Power Drive Wireless Receiver / Codec DAC / Codec AMP QF1D512 f e.g. MAX4411 e.g. CS433x QF1D512 f LeftRight

19. 19 www.quickfiltertech.com Audio Application Digital Wireless Headphones - 2 QF1D512 filters out any unwanted noise, shapes frequency response to suit headphone driver & enclosure Greater control than the built in tone response of the CS44L11 Digital end-to-end solution Wireless Receiver DIGITAL AMP QF1D512 f e.g. CS44L11 QF1D512 f LeftRight

20. 20 www.quickfiltertech.com Audio Application Digital Wireless Speaker QF1D512 filters out any unwanted noise, shapes & limits frequency response to suit driver unit & enclosure Assumes digital transmitted data (I2S) Power Amp may be digital or DAC + analog, as required Wireless Receiver POWER AMP QF1D512 f Equalizer QF1D512 f Additional QF1D512 crossovers + power amps as needed for multi-driver configurations

21. 21 www.quickfiltertech.com Audio Application Pre-Crossover Filtering Data In QF1D512 f to digital crossover circuit Bandpass for protection of speakers RF interference rejection Notch for rec vs. playback audio compensation MCU* (eg ATtiny) * inexpensive (40 cent) MCU can be used for loading the configuration parameters upon start up if a host MCU not present

22. 22 www.quickfiltertech.com Audio Application Bass Management Data In QF1D512 f Bass / Sub Data Out 100Hz LPF MCU* (eg ATtiny) * inexpensive (40 cent) MCU can be used for loading the configuration parameters upon start up if a host MCU not present

23. 23 www.quickfiltertech.com Audio Application Digital crossover Connect as many chips as needed to sub-divide band QF1D512 f Data In HF / Tweeter Data Out QF1D512 f f f Equalizer Bass / Sub Data Out Mid-range Data Out MCU* * inexpensive (40 cent) MCU can be used for loading the configuration parameters upon start up if a host MCU not present