DTMF RECEIVER

HM 9270C/D

- 3 -

Pin

Sym.

Function

11

Q1

12

Q2

13

Q3

14

Q4

15

StD

16

ESt

17

St/GT

18

V

DD

3-state data outputs. When enabled by TOE, provide the code corresponding to the last valid

tone-pair received (see code table).

Delayed steering output. Presents a logic high when a received tone-pair has been registered

and the output latch updated; returns to logic low when the voltage on St/GT falls below

V

Early steering output. Presents a logic high immediately when the digital algorithm detects a

recognizable tone-pair (signal condition). Any momentary loss of signal condition will cause

ESt to return to a logic low.

Steering input/guard time output (bi-directional). A voltage greater than V

causes the device to register the detected tone-pair and update the output latch. A voltage

less than V

The GT output acts to reset the

external steering time-constant; its state is a function of ESt and the voltage on St (see truth

table).

Positive power supply, +5Volts.

DC Electrical Characteristics

Parameter

Description

SUPPLY:

V

DD

Operating Supply Voltage

I

cc

Operating Supply Current

P

o

Power Consumption

I

S

Standby Current

INPUTS:

V

IL

Low Level Input Voltage

V

IH

High Level Input Voltage

I

Input Leakage Current

I

so

Pull Up (Source) Current

R

IN

Input

Signal

Impedance

Inputs 1,2

V

TSt

Steering Threshold Voltage

Test Conditions

Min. Typ. Max. Units

4.75

5.25

V

3.0

7

mA

f=3.579MHz; V

15

35

mW

PWDN pin = V

DD

-

-

100

µA

1.5

V

3.5

V

V

0.1

uA

TOE (Pin 10)=OV

7.5

15

uA

@ 1kHz

10

M

Ω

2.35

V

Parameters

Min.

Max.

Units

Power Supply Voltage, V

6V

Voltage on any pin

V

V

V

Current at any pin

10

mA

Operating temperature

-40

+85

Storage temperature

-65

+150

Package power dissipation

500

mW

Note 1. Absolute maximum ratings are those values beyond which damage to the device may

occur.

2. Unless otherwise specified, all voltages are referenced to ground.