Onboard Complex Frequency Decoder IC MT8870DS
Onboard 5 LED indicators for easy viewing output state
DC Power Supply Voltage：5V(4.5V-5.5V)
Operating Temperature : -40-+85 °C
IO Drive : Current Maximum 10mA.
PCB Size : 25.4×25.4MM
This decoding module is for mobile and fixed telephone voice dialing decoding function
Designed specifically for ARDUINO Board.also use for other MCU(AVR PIC MSP430 STM32 ARM7/9/10/11 FPGA/CPLD)
Does not require any wiring, can be inserted directly into the UNO/MEGA2560/DUE board to use.
12 Digital outputs decode mobile and fixed telephone keys (0-9, * #).Another 4 Digital output(ABCD) can use “DTMF Dial” Software control.
The MT8870 is a complete DTMF receiver integrating both the bandsplit filter and digital decoder functions. The filter section uses switched capacitor techniques for high and low group filters; the decoder uses digital counting techniques to detect and decode all 16 DTMF tone-pairs into a 4-bit code. External component count is minimized by on chip provision of a differential input amplifier, clock oscillator and latched three-state bus interface.
Detailed Block Diagram
Receiver system for British Telecom (BT) or CEPT Spec (MT8870D-1)
Repeater systems/mobile radio
Credit card systems
Telephone answering machine