Handy little digital filter / QuickFilter Technologies: QF4A512

Pressrelease June 2007 (Military Embedded Systems) 

We’ve all been trained to believe that filters come in two primary flavors: low-cost discrete analog types
that drift with time and temperature and full-blown DSP types that are increasingly incorporated in big
honking FPGAs with FFT capabilities. But now there’s an alternative: a nifty little mixed signal FIR filter
that’s designed to sit between an analog input and an MCU or FPGA. The QF4A512 is available in
industrial temperature ranges and designed for use in medical, industrial, military, and myriad other
applications. The fundamental architecture of this little guy is shown in the block diagram - and is so
obvious that it’s a wonder no one ever thought of it before. Implementing any common digital filter
types such as Lowpass, Notched Lowpass, Highpass, Bandpass, Dual Bandpass, Bandstop, Dual
Bandstop, and variations thereof, the key to success is the Windows-based software that allows
designers 512 taps per channel to tune their filter to meet the application. From the four independent
front-end programmable gain amplifiers all the way through the 16-bit A/Ds and into the programmable filter sections, the user can configure gain, A-to-D sampling rate, power consumption, and output speed. Nearly everything about the device is programmable, making it an ideal way to perform complex - er, make that “sophisticated” - filtering without requiring costly and power-hungry FPGAs. In fact, the back-end SPI interface is designed to bolt up to 8051s. Ti MSP430s. ARM7TDMIs, and anything in between. The QF4A512 is only one of the company’s serveral ingenious devices, and there are development boards, reference designs, and way-cool software tools that’ll even talk to MatLab. We think this device is pretty amazing.