HT8972
Functional Description
·
The HT8972 is an echo/surround effect generator with
built-in 40Kb SRAM. It ensures low distortion as well as
low noise for processing audio signal delay. The chip
provides two playing modes (echo and surround) and
the playing function block diagrams are shown as fol-
lows.
Echo mode
V
O
U
T
V
I
N
L
P
F
1
A
/
D
D
e
l
a
y
D
/
A
L
P
F
2
·
Surround mode
V
I
N
V
O
U
T
L
P
F
1
A
/
D
D
e
l
a
y
D
/
A
L
P
F
2
R
OSC-fOSC-Delay_time-Distortion Cross table
ROSC
fOSC
Td
56.2
2
44
2.5
36.3
3
30.6
3.5
25.9
4
23.1
4.5
20.7
5
kW
MHz
ms
320
1.3
264
1.05
219
0.815
188
164
0.58
147
132
0.43
THD
0.625
0.525
%
ROSC
fOSC
Td
18.5
5.5
16.7
6
15.1
6.5
14.5
7
13.9
7.5
88
11.9
8
10.9
8.5
kW
MHz
ms
120
0.4
110
0.335
102
93
82
78
THD
0.315
0.3
0.275
0.26
0.25
%
ROSC
fOSC
Td
10
9
9
8.06
11
7.3
12
6.4
13
5.8
14
46
5.3
15
44
kW
MHz
ms
10
73.2
0.23
65.6
0.218
59.2
0.205
54.4
0.19
50
THD
0.17
0.1675
0.1575
%
ROSC
fOSC
Td
4.8
16
4.4
17
4
18
3.7
19
3.3
20
3
21
2.8
22
kW
MHz
ms
41.2
0.16
38.4
0.145
36
33.6
0.14
33
32
30
THD
0.14
0.13
0.125
0.12
%
Rev. 1.00
5
December 23, 2008
HOLTEK [ HOLTEK SEMICONDUCTOR INC ]
