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Dev Kit
Q: Do I need to terminate the unused inputs on the development board?
A: You may notice the noise floor moving around on the “non-terminated” inputs. For a clean looking noise floor on the FFT, terminate the unused inputs with standard 50 ohm terminators.
Q: How are the analog inputs configured on the development kit?
A: When shipped the inputs are set to ac coupled, single ended. Refer to the documents folder of your software install for altering the configuration.
Q: How much power do I have for the prototyping area?
A: The development board uses all linear regulators for low noise power supplies. Typically the board uses between 225mA to 350mA out of an available 500mA from the USB. So, on average there is about 200mA of power from the combined 5V and 3.3V labeled power on the development board.
Q: What power supply do I need for the Dev Kit.
A: None! The board as shipped is powered from the USB port. Alternatively you may provide your own 5V power using two header pins in the lower right of the board. Consult the documentation folder of your software install for further information.
Q: Why is the external power connector J7 empty, and what is it used for on the development kit?
A: The external power connector is available for applications that require more than 1 Watt of power used in the prototyping area, or very clean external power is required for precise signal to noise ratio measurements. Removing diode D8 eliminates the noisier power coming from the USB port, while still allowing communication with Quickfilter’s software.
Dev Kit Registration
Q: When I try to register my development kit I get a message stating invalid serial number.
A: There are a couple of possible reasons for this. 1. The input field consists of two letters followed by 4 digits. Do not insert a hyphen between the letters and numbers. 2. Someone else may have already registered the kit with that serial number, perhaps a colleague. If you think this has occurred please contact us to rectify the situation.
QF4A512
Q: Can I use a different input clock frequency?
A: Yes, within the data sheet specified range of frequencies. The Development Software allows you to specify the frequency for your application when developing an ic configuration. However, to have the development kit accurately reflect your application you will also need to change the frequency on the development board itself.
Q: Can I use my own system clock instead of the 20 MHz crystal?
A: Yes, you can save the cost of the crystal by using a clock from the target system. See application note QF0011 “Using an external clock” for limitations and correct software generation.
Software
Q: Do I need to terminate the driver install because of the Microsoft logo warning?
A: No. Our supplier does not provide Microsoft WHQL certified drivers at this time. The drivers have been used extensively by both the manufacturer and Quickfilter on the platforms support by our application.
Q: Does Quickfilter intend to add other filter types?
A: Yes. If you have registered your kit and requested update notification we will send you e-mail when new filters are added. We would also like to hear from you to request specific filter types.
Q: I could not install the Quickfilter Software on Windows 2000, the error reported I needed an updated installer. What's up?
A: Make sure you have Service Pack 4 installed on the Windows 2000 computer. http://www.microsoft.com/windows2000/downloads/servicepacks/sp4/default.mspx
Q: My lowpass filter shows a definite rolloff at lower frequencies. Why?
A: If you are using your PC soundcard as a signal source it will typically roll off at the lower frequencies (and also above 20kHz). This droop will disappear if you use a lab quality source.
Q: What is the function of the "Optimize Power" checkbox on the Config screen?
A: This checkbox only has any effect if you are designing a multiple channel configuration AND you have more than one group selected on page two of Config. If checked the software will configure the device to power down this channel when its corresponding group is not active. The only downside to this option is that when the group becomes active it may take slightly longer to power up the channel than if it was left in a powered state.
Q: What is the function of the "Optimize Precision" checkbox on the Config screen?
A: When this box is checked (default) the software will try and set up an ADC clock rate of at least 100x the sampling frequency of that channel. This will achieve the maximum precision of the conversion result. If an oversampling rate of 100x can not be achieved, for example due to a very high sampling frequency or multiple chnnels exceeding the maximum SPI bandwidth, this box can be unchecked allowing oversampling rates down to 8x.
Q: What is the latest released software revision?
A: See the Software Updates page for this information.
Q: When configuring an IC why did the software change the sample rate and number of taps on the filters I loaded?
A: The software has to derive the sampling rate for each channel based on a common ADC clock rate. Therefore it may be necessary to slightly alter the sampling rate for a specific channel. In turn the number of taps is recalculated to achieve the requested filter performance.
Q: Why are two drivers installed?
A: The first driver is the USB driver and the second driver is the virtual common port driver.
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