MT8870 DTMF Decoder Module 3.5mm Audio Jack
Rs 490.00
Quick Info :
- Decoder IC : MT8870DS
- Decoded Tones : 16 (0–9, *, #, A–D)
- Output : 4-bit binary (Q1–Q4) + StD pin
- Audio Input : 3.5mm AUX jack
- Clock : 3.579545 MHz crystal oscillator
- Operating Voltage : 5V DC (TTL logic)
- LED Indicators : Yes (4 × output state LEDs)
- Compatible Boards : Arduino / ESP32 / PIC / STM32
The MT8870 DTMF Decoder Module is a compact, ready-to-use tone decoding solution built around the MT8870DS complete DTMF receiver IC, enabling any microcontroller to interpret keypad dial tones from a mobile phone or telephone through a standard 3.5mm audio jack — with zero external signal processing circuitry required.
DTMF (Dual Tone Multi-Frequency) is the signalling standard used by telephone keypads, where each key press generates a unique combination of two sine wave frequencies. The MT8870 module receives this audio signal, separates it through an onboard switched-capacitor band-split filter, and decodes it into a clean 4-bit binary output (Q1–Q4) representing all 16 possible tones — digits 0–9, symbols * and #, and characters A through D. A StD (Delayed Steering) output pin goes HIGH when a valid tone is detected, making it easy to trigger microcontroller routines only on confirmed key presses.
Onboard LED indicators provide instant visual feedback of the decoded output state during development and testing. The module connects to any microcontroller using just four digital input pins plus the StD pin — fully compatible with Arduino UNO, Mega2560, DUE, ESP32, PIC, and STM32. An internal operational amplifier with user-adjustable guard time ensures reliable tone detection even in noisy audio environments. Widely used for mobile phone-controlled robots, home automation, remote access systems, IVRS applications, and GSM-based control projects.
Specifications :
- Decoder IC : MT8870DS (Complete DTMF Receiver)
- Decoded Tones : 16 (0–9, *, #, A, B, C, D)
- Digital Output : 4-bit binary (Q1, Q2, Q3, Q4)
- Valid Tone Indicator : StD pin (Delayed Steering Output)
- Audio Input : 3.5mm stereo audio jack (AUX)
- Onboard Filter : Switched-capacitor band-split filter (high & low group)
- Internal Amplifier : Differential input op-amp with adjustable gain
- Guard Time : User-adjustable
- Output LED Indicators : Yes (4 × onboard LEDs for Q1–Q4)
- Operating Voltage : 5V DC
- Logic Level : TTL (5V compatible)
- Clock : Onboard crystal oscillator (3.579545 MHz)
- Power-Down Mode : Supported
- Inhibit Mode : Supported
- Output Type : Latched 3-state bus interface
- Compatible Boards : Arduino UNO / Mega2560 / DUE / ESP32 / PIC / STM32
