hsp50214a Intersil Corporation, hsp50214a Datasheet - Page 16

• Manufacturer Part Number: hsp50214a
• Description: Programmable Downconverter
• Manufacturer: Intersil Corporation

.
NOTE: If 14 input bits are not needed, the gain adjust can be in-
creased by one for each bit that the input is shifted down at the
input. For example, if only 12 bits are needed, an offset range of
24dB is possible for a decimation of 24.
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
FIGURE 16. CIC FILTER BIT WEIGHTING
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
2
2
2
2
2
2
2
2
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
-32
-33
-34
-35
-36
-37
-38
-39
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-32
-33
-34
-35
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-18
-19
-20
-21
-22
-23
-24
-25
-26
-27
-28
-29
-30
-31
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
0
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
-1
-2
-3
-18
-19
-20
-21
-22
-23
-4
-5
-6
-7
-8
-9
-10
-11
-12
-13
-14
-15
-16
-17
HSP50214A
16
Since each halfband filter section decimates by 2, the total
decimation through the halfband filter is given by:
where N = Number of Halfband Filters Selected (1 - 5).
DEC
CONTROL WORD 7, BIT 19
†
FIGURE 17. BLOCK DIAGRAM OF HALFBAND FILTER
Each halfband section decimates by 2.
CONTROL WORD 7, BIT 18
F
N
CONTROL WORD 7, BIT 17
F
HB
= F
N
FILTER INPUT
= F
HB4
=
CONTROL WORD 7, BIT 16
F
HALFBAND
N
2
CONTROL WORD 7, BIT 15
F
HB3
= F
N
N
SECTION
= F
HB2
HB1
F
N
= f
IN
0
HALFBAND FILTER 5
0
F
1
5
HALFBAND FILTER 4
= F
0
1
F
HB4
HALFBAND FILTER 3
HB4
0
F
1
HALFBAND FILTER 2
HB3
= F
0
F
OR F
1
HALFBAND FILTER 1
HB2
HALFBAND
FILTER OUTPUT
HB3
= F
1
F
HB4
HB1
HB2
= F
OR F
HB1
/2
= f
OR F
HB3
f
†
IN
S
OR F
OR f
= f
HB2
/2
†
(EQ. 9)
S
†
HB1
S
/2
/2
†
/2
†