HT9170B/HT9170D

DTMF Receiver

Selection Table

Function

Operating

Voltage

OSC

Frequency

Tristate

Data Output

Power

Down

1633Hz

Inhibit

DV

DVB

Package

Part No.

HT9170B

2.5V~5.5V

3.58MHz

ÖÖ

Ö

Ö

¾

18 DIP

HT9170D

2.5V~5.5V

3.58MHz

ÖÖ

Ö

Ö

¾

18 SOP

Block Diagram

Rev. 1.10

1

September 24, 2002

Features

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.

O P A

X 2

X 1

3 . 5 8 M H z

C r y s t a l

O s c i l l a t o r

V r e f

G e n e r a t o r

L o w G r o u p

. i l t e r

H i g h G r o u p

. i l t e r

S t e e r i n g C o n t r o l C i r c u i t

P r e - . i l t e r

V P

V N

G S

. r e q u e n c y

D e t e c t o r

C o d e

D e t e c t o r

L a t c h

&

O u t p u t

B u f f e r

O E

V R E .

R T / G T

E S T

D V

D 0

D 1

D 2

D 3

I N H

B i a s

C i r c u i t

P W D N

D V B