ZHCSEA4C May 2015 – December 2020 ADS54J40
PRODUCTION DATA
In this configuration, the DDC block includes a fixed digital fS / 4 mixer. Thus, the IQ pass band is approximately ±110 MHz, centered at fS / 4. This decimation filter has 41 taps with a latency of approximately ten output clock cycles. The stop-band attenuation is approximately 90 dB and the pass-band flatness is ±0.05 dB. Table 8-3 shows the corner frequencies for a low-pass, decimate-by-4 IQ filter.
CORNERS (dB) | LOW PASS |
---|---|
–0.1 | 0.107 × fS |
–0.5 | 0.112 × fS |
–1 | 0.115 × fS |
–3 | 0.120 × fS |
Figure 8-8 and Figure 8-9 show the frequency response of a decimate-by-4 IQ output filter from dc to fS / 2.