Part Number: MT8870DE

Manufacturer: Mitel Networks Corporation

Description: Integrated DTMF Receiver with Enhance Sensitivity

Shipped from: Shenzhen/HK Warehouse

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Technical Specifications of MT8870DE1

Datasheet  MT8870DE1 datasheet
Category Integrated Circuits (ICs)
Family Interface – Telecom
Manufacturer Microsemi Corporation
Packaging Tube
Part Status Active
Function DTMF Receiver
Number of Circuits 1
Voltage – Supply 4.75 V ~ 5.25 V
Current – Supply 3mA
Power (Watts)
Operating Temperature -40°C ~ 85°C
Mounting Type Through Hole
Package / Case 18-DIP (0.300″, 7.62mm)
Supplier Device Package 18-PDIP

The majority of modern telephone equipment has a DTMF receiver integrated circuit electronic communications circuits, the Motorola MT8870 is a well-known integrated circuit (IC) that is commonly used.

It is a DTMF receiver. The MT8870 integrated circuit has 18 pins. In addition to being utilized in a wide range of other applications, it is utilized in telephones. The engineers or technicians working on the project must test this IC independently if the projects that employ it fail to deliver the desired results. A speedy evaluation of this integrated circuit might save significant time in research labs and enterprises that manufacture communication equipment. This is a compact and convenient tester circuit for the DTMF integrated circuit. It could be assembled using a flexible printed circuit board and an 18-pin IC base.  On top of that, the integrated circuit can be tested using a regular breadboard.

The DTMF receiver in a telephone should be built to recognize a genuine tone pair with a duration of more than 40 milliseconds and to accept successive digit tone pairs that are spaced farther than 40 milliseconds apart. This will ensure that the Telephone works as efficiently as possible. On the other hand, the tone length might differ for some applications, such as radio communications and remote controls, because of noise issues. As a result, the tone length can be changed to various values by including an additional resistor and guiding diode in the circuit.

MT8870DE Description

MT8870DE Description

The MT8870 is a full-featured DTMF receiver that combines the band split filter and digital decoder operations into a single device. High and low group filters are made in the filter section utilizing switched capacitor techniques.

The decoder recognizes and converts each of the 16 DTMF tone-pairs into a four-bit code using digital counting algorithms. On-chip provisions of a clock oscillator, latched three-state bus interface and differential input amplifier help reduce the number of external components required.

MT8870DE Features & Benefits

  • It has a Complete DTMF Receiver.
  • It consumes little power.
  • It has a built-in gain-setting amplifier.
  • It has a variable guard time.
  • Features high-quality central office.
  • There is a Power-down mode on it.
  • It includes the Inhibit mode.
  • It offers MT8870C/MT8870C-1 Backward Compatibility.

MT8870DE Typical Applications

  • It is utilized in paging systems.
  • It is utilized in mobile radio and repeater systems.
  • Credit card systems employ it.
  • It is utilized in the remote control.
  • It is present in personal computers.
  • It is utilized in answering machines for phones.

Frequently Asked Questions

What is DTMF used for?

Dual-tone multi-frequency, most commonly abbreviated as DTMF, is a method that can be used to dial telephone numbers or to deliver commands to switching systems. Over analog telephone lines and voice-frequency bands, DTMF is the predominant method of telecommunication signaling utilized between telephone handsets and switching centers.

What is meant by DTMF?

When you press the touch keys on a standard telephone, the signal sent to the phone company is called DTMF, which stands for “dual-tone multi-frequency.” “Touchtone” is the name given to this type of phone in the United States and possibly in other countries (formerly a registered trademark of AT&T). DTMF dialing has mostly taken the role of the older loop disconnect (or “pulse”) method.

How Does DTMF work?

When using DTMF, each key pressed on a phone generates two tones of the specified frequencies. One tone is generated from high-frequency tones and low-frequency tones. DTMF keypads are laid out on four-by-four matrices, with each row representing low frequency and each column representing high frequency.

What’s DTMF on a cell phone?

Tones known as dual-tone multi-frequency (DTMF) tones are utilized by automated dial-in systems like voicemail and other places where prompts are used to navigate. (found in the upper right-hand corner). Click the Call Settings button. DTMF tones can be tapped.

What is DTMF?

There are virtually as many applications for DTMF keypads on landlines as on mobile phones. As a result, this keypad is utilized in the telephone exchange rooms to recognize the number that the caller dialed. A DTMF decoder, such as the MT8870DE, can discern between DTMF tones and produce a binary sequence corresponding to the number of key presses on a DTMF keypad.

Do cell phones use DTMF?

DTMF is the universally accepted standard for the auditory tones that indicate the digits on a telephone keypad. However, DTMF is still utilized over mobile phones to navigate automated systems such as phone menus and for secondary dialings such as a calling card. Digital signals rather than DTMF handle direct dialing on mobile phone networks.

What does DTMF mean on a cell phone?

DTMF is an abbreviation for dual-tone multi-frequency, referring to the tones a phone’s speaker and microphone can transmit.

Why does DTMF use two tones?

A technology known as DTMF (Dual Tone Multiple Frequency) is used to deliver signals for button presses on telephones. The data is often transmitted over speech channels; hence, to differentiate itself from a human voice, the phone generates two tones of different frequencies whenever you press a button on it: one with a low frequency and one with a high frequency.

What is dual tone multiple frequencies (MT8870)?

Dual Tone Multiple Frequency technologies were created by Bell Labs to take the place of pulse dialing in telephones. These technologies are known as DTMF. The MT8870 is a DTMF Decoder module that responds to the DTMF audio signal by producing a four-bit digital code. The MT8870 Decoder IC has an operational amplifier with a user-adjustable Guard time built in.

How many DTMF tone pairs are used in the 4-bit code?

All 16 DTMF tone pairs are detected by these devices, which then decode them all into a 4-bit code output. -Very accurate switching capacitor filters are utilized when dividing tone signals into low and high group signals.

What is DTMF decoding?

DTMF Decoder is a program that makes decoding DTMF dial tones found on telephone lines compatible with touchtone phones relatively simple. The DTMF Decoder is also utilized in amateur radio frequency bands to receive data communications.


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