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Sensors & Modules

MT8870D Integrated ISO2-CMOS DTMF Receiver Module

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Package SOIC-20, SSOP, PDIP
MT8870D datasheet (PDF) Preview Buy MT8870D
MT8870D-Integrated-ISO2-CMOS-DTMF-Receiver-Datasheet

MT8870D overview

MT8870 module is a low-power device DTMF decoder. It is a complete DTMF receiver integrating both the band-split filter and digital decoding functions. This module is suitable for modem interfaces, mobile radios, and other DTMF-related applications. DTMF (Dual Tone Multi-Frequency) signaling is used for telecommunication signaling over the telephone lines in the voice frequency band between communication devices (telephone, mobile).

DTMF is commonly found in tone-based dial pad devices such as mobile phones or telephone dial pads. When the dial pad is pressed, it produces a combination of two separate sine waves which is a unique frequency signal that can be decoded and produced as a binary output. MT8870 Decoder is integrated with an operational amplifier with user-adjustable Guard time. The embedded band-split filter uses switch capacitor techniques to distinguish and split low and high frequencies from the received signal.

MT8870D-Integrated-ISO2-CMOS-DTMF-Receiver-Module

Key specifications

PCB Size
26.5 x 24.5 mm
Operating Voltage
4.75 – 5.25 Volts
Operating Temperature
-400C – 850C
Oscillator Frequency
3.579545 MHz
Source/Sink Current
10 mA
Power Dissipation
500 Watts
Minimum Op-Amp Gain
0.30 MHz

Datasheet

mt8870d-datasheet-oct2006.pdf
Format PDFSize 428 KBLanguage EN
Third-party / unverified source
Open datasheet Download

MT8870D features

  • Complete DTMF (Dual Tone Multi-Frequency) Receiver
  • Low power consumption
  • Internal gain setting amplifier
  • Adjustable guard time
  • Central office quality
  • Power-down mode
  • Inhibit mode
  • Backward compatible with MT8870C/MT8870C-1
  • On-board voice input interface
  • On-board LED it is very convenient to check the output state.

MT8870D pinout

MT8870D pinout diagram
NameDescription
Q1Binary Bit 1
Q2Binary Bit 2
Q3Binary Bit 3
Q4Binary Bit 4
StQDelayed String Output
StQPower Down Input
INInhibit Input
VCCDC Supply Input
GNDGround

MT8870D applications

  • Receiver system for British Telecom (BT) or CEPT Spec (MT8870D-1)
  • Paging systems
  • Repeater systems/mobile radio
  • Credit card systems
  • Remote control
  • Personal computers
  • Telephone answering machine

More about MT8870D

MT8870D Pinout

Pin NamePin FunctionDescription
Q1Binary Bit 1Binary Output Pin 1
Q2Binary Bit 2Binary Output Pin 2
Q3Binary Bit 3Binary Output Pin 3
Q4Binary Bit 4Binary Output Pin 4
StQDelayed String OutputRepresents Binary Bit 0
StQPower Down InputTriggers Power down sequence
INInhibit InputLogic high inhibits the detection of tones representing characters A, B, C, and D
VCCDC Supply Input4.5V - 5.5V (5.0V Nominal)
GNDGroundGround Pin of the Module

MT8870D Specifications

  • On-board MT8870 frequency decoder chip
  • On-board audio input interface
  • On-board LED lights for output state indication

Datasheet MT8870D

See Also: CD4059 Program Divide-by-N Counter | 74LS156 Dual 2 To 4 Line Demultiplexer (Open Collector) | HC12 SI4463 433Mhz Wireless RF Serial Port Module

MT8870D datasheet PDF preview

PDF · 428 KB

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