|
|
Article: Flatten DAC frequency response: equalizing techniques can cope with the nonflat frequency response of a DAC.(MAXIM INTEGRATED PRODUCTS)(digital-to-analog converter design)
- Article from:
- EDN
- Article date:
- April 13, 2006
- Author:
CopyrightCOPYRIGHT 2006 Reed Business Information, Inc. (US). This material is published under license from the publisher through the Gale Group, Farmington Hills, Michigan. All inquiries regarding rights should be directed to the Gale Group. (Hide copyright information)
|
In a generic example, a DAC samples a digital baseband signal (Figure 1). The DAC's frequency response is not flat; it attenuates the analog output at higher frequencies. At 80% of [f.sub.NYQUIST], for instance ([f.sub.NYQUIST] = [f.sub.S]/2), the frequency response attenuates by 2.42 dB. That amount of loss is unacceptable for some broadband applications requiring a flat frequency response. Fortunately, however, several techniques can cope with the nonflat frequency response of a DAC. These techniques include increasing the DAC's update rate using interpolation techniques, pre-equalization filtering, and post-equalization filtering, all of which reduce or eliminate the ...