HSP50415EVAL1 Intersil, HSP50415EVAL1 Datasheet - Page 13

• Manufacturer Part Number: HSP50415EVAL1
• Description: EVALUATION BOARD HSP50415VI
• Manufacturer: Intersil
• Type: Modulator, Demodulatorr

Specifications of HSP50415EVAL1

• For Use With/related Products: HSP50415
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Typical Performance Curves
Carrier NCO and Complex Mixer
Following the interpolating filter is the complex mixer stage
where the quadrature data is modulated onto a carrier signal
via a complex multiply operation resulting in a quadrature
output sample. The carrier NCO has a 32-bit programmable
frequency increment value which is programmed as follows:
carrierPhinc = (carrierFrequency / FSout) * 2^32
The frequency may be positive or negative with a range from
-50 to +50MHz (for FSout of 100MHz). The phase adder and
accumulator are also 32-bits wide.
-100
-110
-120
-10
-20
-30
-40
-50
-60
-70
-80
-90
0
FIGURE 15.
0
RESPONSE FOR L = 6; FOUT = 4096
512
INTERPOLATION FILTER RESPONSE
SAMPLE TIMES
13
1024
-100
-110
-120
-10
-20
-30
-40
-50
-60
-70
-80
-90
0
0
FIGURE 17.
(Continued)
1536
512
RESPONSE FOR L = 10; FOUT = 4096
2048
HSP50415
INTERPOLATION FILTER RESPONSE
SAMPLE TIMES
1024
X/SIN(X) Compensation Filters
Following the complex mixer stage is a pair of fixed
coefficient 11-tap X/SIN(X) compensation filters. The
X/SIN(X) filter performs peaking to compensate for the
SIN(X)/X rolloff that occurs at the output of the DACs. These
filters may be totally bypassed if not required. The X/SIN(X)
filter coefficients are:
-1, 2, -4, 10, -34, 384, -34, 10, -4, 2, -1
The output is rounded to 16-bits. The output of the filter is
not checked for saturation since the maximum sum of
products is 486/512 (0.949) and overflow will never occur.
The data exits the X/SIN(X) filters as a parallel I<15:0> and
Q<15:0> data streams at the final sample rate. Figure 18
plots of the inverse sinc function, sinc function, and the effect
of compensation.
-100
-110
-120
-10
-20
-30
-40
-50
-60
-70
-80
-90
FIGURE 16.
1536
0
0
RESPONSE FOR L = 8; FOUT = 4096
512
2048
INTERPOLATION FILTER RESPONSE
SAMPLE TIMES
1024
1536
April 23, 2007
FN4559.6
2048