ML6420
DIGITAL FILTER
HALF-BAND
SIGNAL
PROCESSING
ADC
DAC
ANALOG IN
ANALOG OUT
ML6420
9.3MHz TYP
x2
F CLOCK
0
Figure 13. Oversampled Video Processing System with
Analog LPF & Half-Band Digital Filter
ANALOG FILTER REDUCES
ERRORS FROM F TO 2xF
0
0
AT THE INPUT OF
THE ADC
DESIRED PASSBAND
SIGNAL CONTENT
ANALOG/DIGITAL COMBO
YIELDS LOW ALIASING
ERRORS
DSP FILTER REDUCES
ERRORS FROM F /2
0
TO F AT THE
0
OUTPUT OF
THE ADC
0Hz
F /2
0
F
2xF
0
0
Figure 14. Digital Filtering in the Frequency Domain
HIGH FREQUENCY ELEMENTS THAT ARE REDUCED IN AMPLITUDE
AND BROADENED TO COVER MORE THAN 1 PIXEL.
SAMPLING CLOCK
AT OUTPUT
0
t
Figure 15. Digital Filtering in the Time Domain
18