HT9170B/HT9170D
DTMF Receiver
Features
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Operating voltage: 2.5V~5.5V
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Minimal external components
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No external filter is required
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Low standby current (on power down mode)
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Excellent performance
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Tristate data output for MCU interface
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3.58MHz crystal or ceramic resonator
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1633Hz can be inhibited by the INH pin
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HT9170B: 18-pin DIP package
HT9170D: 18-pin SOP package
General Description
The HT9170B/D are Dual Tone Multi Frequency (DTMF)
receivers integrated with digital decoder and bandsplit
filter functions as well as power-down mode and inhibit
mode operations. Such devices use digital counting
techniques to detect and decode all the 16 DTMF tone
pairs into a 4-bit code output.
Highly accurate switched capacitor filters are imple-
mented to divide tone signals into low and high group
signals. A built-in dial tone rejection circuit is provided to
eliminate the need for pre-filtering.
Selection Table
Function
Part No.
HT9170B
HT9170D
Operating
Voltage
2.5V~5.5V
2.5V~5.5V
OSC
Frequency
3.58MHz
3.58MHz
Tristate
Data Output
脰
脰
Power
Down
脰
脰
1633Hz
Inhibit
脰
脰
DV
脰
脰
DVB
戮
戮
Package
18 DIP
18 SOP
Block Diagram
P W D N
X 2
X 1
3 .5 8 M H z
C ry s ta l
O s c illa to r
B ia s
C ir c u it
V re f
G e n e ra to r
S te e r in g C o n tr o l C ir c u it
V R E .
R T /G T
E S T
D V
D V B
L o w
V P
V N
G S
O P A
P r e - . ilte r
G ro u p
. ilte r
. re q u e n c y
D e te c to r
C o d e
D e te c to r
H ig h G r o u p
. ilte r
L a tc h
&
O u tp u t
B u ffe r
D 0
D 1
D 2
D 3
IN H
O E
Rev. 1.10
1
September 24, 2002