HM9270D Ver la hoja de datos (PDF) - ELAN Microelectronics

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componentes Descripción

Fabricante

HM9270D

DTMF RECEIVER

ELAN Microelectronics 

Block Diagram (Figure 1)

HM 9270C/D

DTMF RECEIVER

INH

HIGH

GROUP

DIGITAL

CODE

Q1

FILTER ZERO

CROSSING

CONVERTER

Q2

IN+

+

DIAL

DETECTORS DETECTION

IN

-

TONE

FILTER

LOW

AND

Q3

GROUP

FILTER

ALGORITHM

LATCH

Q4

GS

CHIP CHIP CHIP CHIP

CLOCKS POWER BIAS REF

OSC2

BIAS

+

CIRCUIT

-

STEERING

LOGIC

OSC1

VDDVSS PWDN

VREF St/ GT ESt

StD

TOE

Pin Description

Pin Sym.

Function

1

IN+

2

IN-

Non-Inverting input

Invering Input

Connections to the front-end differential amplifier.

3

GS

Gain select. Gives access to output of front-end differential amplifier for connection of

feedback resistor.

4

VREF

Reference voltage output,nominally V /2. May be used to bias the inputs at midrail (see

DD

application diagram).

5

INH

Inhibit (input) logic high inhibit the detection of 1633Hz internal built-in pull down resistor.

(HM9270D only).

6

PWDN Power down (input). Active high power down the device and inhibit the oscillator internal

built-in pull down resistor. (HM9270D only).

7

OSC1 Clock Input

8

OSC2 Output

3.579545 MHz crystal connected between these pins completCeslock

internal oscillator.

9

V

SS

Negative power supply, normally connected to 0V.

10

TOE

3-state data output enable (input). Logic high enables the outputs Q1-Q4. Internal pull-up.

-2-

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