Analog Devices SHARC ADSP-21368

Theory of Operation
10-6 ADSP-21368 SHARC Processor Hardware Reference
F is the frequency of the worst-case image which is:
and f
S_INTERP
is
The following worst-case images would appear for f
S_IN
= 192 kHz:
Image at f
S_INTERP
– 96 kHz = –125.1 dB
Image at f
S_INTERP
+ 96 kHz = –125.1 dB
Figure 10-3. Frequency Domain of the Interpolation and Resampling
2
20
f
S_IN
×
f
S_IN
2
------------
±
f
S_IN
2
20
×
FREQUENCY DOMAIN OF SAMPLES AT f
S_IN
FREQUENCY DOMAIN OF THEINTERPOLATION
FREQUENCY DOMAIN OF f
S_OUT
RESAMPLING
FREQUENCY DOMAIN AFTER
R
E
S
AMPLING
IN OUT
f
S_IN
f
S_OUT
INTERPOLATE
BY N
LOW-PASS
FILTER
ZERO-ORDER
HOLD
f
S_IN
220 × f
S_IN
220 × f
S_IN
220 × f
S_IN
SIN(X)/X OF ZERO-ORDER HOLD