HSP50214B_14 Datasheet, PDF (11/62 Pages) Intersil Corporation – Programmable Downconverter

HSP50214B
f_S
5MHz
2f_S
10MHz
3f_S
4f_S
5f_S
15MHz 20MHz 25MHz
6f_S
30MHz
7f_S
8f_S
35MHz 40MHz
THE INPUT DATA SPECTRUM SAMPLED AT RATE R = f_S
9f_S
45MHz
10f_S
50MHz
f’_S / 8
5MHz
f’_S/4
10MHz
3f’_S/8
15MHz
f’_S/2
20MHz
5f’_S / 8
25MHz
3f’_S / 4
30MHz
7f’_S / 8
f’_S
35MHz 40MHz
FIGURE 6. INTERPOLATION SPECTRUM: INTERPOLATE BY 8 THE INPUT DATA WITH ZERO STUFFING; SAMPLE AT RATE R = f’s
4MHz 8MHz 12MHz 16MHz 20MHz 24MHz 28MHz 32MHz 36MHz 40MHz
DECIMATE BY 10 AND CIC FILTER; SAMPLE AT RATE R = f’s/10
85dB DYNAMIC RANGE BANDWIDTH
O.5MHz 1MHz
CIC FILTER ALIAS PROFILE
2MHz
3MHz
CIC FILTER
FREQUENCY
RESPONSE
4MHz
FIGURE 7. ALIAS PROFILE AND THE 85dB DYNAMIC RANGE BANDWIDTH
μPROC
DAC
INPUT LEVEL
DETECTOR (24-BIT
ERROR VALUE)
IF
INPUT
GCA
THRESH
A/D
PDC
FIGURE 8. PROCESSOR BASED EXTERNAL IF AGC
11
FN4450.4
May 1, 2007