HT9170B_02 Datasheet, PDF (1/13 Pages) Holtek Semiconductor Inc – DTMF Receiver

HT9170B/HT9170D
DTMF Receiver
Features
· Operating voltage: 2.5V~5.5V
· Minimal external components
· No external filter is required
· Low standby current (on power down mode)
· Excellent performance
· Tristate data output for MCU interface
· 3.58MHz crystal or ceramic resonator
· 1633Hz can be inhibited by the INH pin
· 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.
Operating
Voltage
HT9170B 2.5V~5.5V
HT9170D 2.5V~5.5V
OSC
Frequency
3.58MHz
3.58MHz
Tristate
Data Output
Ö
Ö
Power
Down
1633Hz
Inhibit
DV DVB Package
Ö
Ö
Ö
¾ 18 DIP
Ö
Ö
Ö
¾ 18 SOP
Block Diagram
X2
3 .5 8 M H z
X1
C ry s ta l
O s c illa to r
PW DN
VRE.
B ia s
C ir c u it
V re f
G e n e ra to r
R T /G T E S T
DV
DVB
S te e r in g C o n tr o l C ir c u it
VP
O PA
VN
GS
P r e - . ilte r
L o w G ro u p
. ilte r
H ig h G r o u p
. ilte r
D0
L a tc h
. re q u e n c y
C ode
&
D1
D e te c to r
D e te c to r
O u tp u t
B u ffe r
D2
D3
IN H
OE
Rev. 1.10
1
September 24, 2002