Nuvoton CODEC 8812 series User Manual

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Nuvoton CODEC 8812 series User Manual Manual pdf 38 page image

CODEC Motherboard Manual Version 1.3 Page 38 of 66 April 12, 2016CODEC Motherboard17 Daughter Card SystemThe daughter card is the small PCB mounted onto a socket connector on the main EVBmotherboard, and this contains the device being evaluated. This arrangement enables a singleEVB hardware and software system to support testing of a very wide range of Nuvoton audioproducts in a consistent, stable, and easy to use environment.17.1 Changing Daughter CardsIf it is desired to use a different daughter card on the system, it is best to first completely remove all powerconnections to the EVB. Then, simply remove the existing daughter card and insert the new daughter cardin the same location.IMPORTANT: When inserting the new daughter card, make certain that the Pin #1 alignment matches thePin #1 location indicated on the motherboard. Also, be careful to mount the daughter card so that all fourrows of connectors are in fact connected. It is possible to offset the daughter card horizontally so that somerows are connected and other rows are not connected.A good technique to insert a new daughter card is to hold the card at an angle so that it can beseen clearly visually that one row is completely and correctly aligned. After this first row begins tobecome connected, then in a rolling or rotating motion, swing the daughter card so that it isparallel with the motherboard and push to engage all of the other connectors.17.2 NAU8822 Daughter CardThe new style NAU8822 daughter card includes series resistors on all of the low-current analogand digital signal paths. Most are zero-ohm resistors, but some have a small value to optimizeclock signal integrity. A schematic diagram of the daughter card is included for reference.The series resistors make it easy to modify the daughter card for experimentation, eliminating theneed to cut actual foil traces on the PCB. Additionally, test points are included for:* digital ground (convenient for attaching test equipment)* analog ground (important for precise analog performance measurement)* Vref (AC and DC voltage reference used by the device)A built-in microphone is also included on the new style daughter card. This can be connected bymoving the two left microphone path jumpers, J11 and J14, from the normal location on the EVBonto the J1 and J2 pin-pairs on the daughter card as shown in the picture below. The Demopanel option for microphone input will now operate using the built-in microphone.