MT8870DS Integrated DTMF Receiver, SOIC-18 Package

The MT8870DS is an ISO2-CMOS integrated DTMF (Dual-Tone Multi-Frequency) receiver that combines both the band-split filter and digital decoder functions into a single chip. Utilizing switched capacitor techniques, the filter section separates high and low group tones, while the decoder employs digital counting techniques to detect and decode all 16 DTMF tone pairs into a 4-bit code. The device minimizes external component requirements by providing an on-chip differential input amplifier, clock oscillator, and latched three-state bus interface. Its low power consumption and power-down mode make it ideal for various applications, including paging systems, repeater systems, credit card systems, remote control, personal computers, and telephone answering machines.

• Complete DTMF Receiver: Integrates both band-split filter and digital decoder functions, providing a comprehensive solution for Dual-Tone Multi-Frequency (DTMF) signal reception.
• Low Power Consumption: Designed for efficient power usage, making it suitable for battery-operated and low-power applications.
• Internal Gain Setting Amplifier: Includes an internal amplifier with adjustable gain, allowing for flexible input signal conditioning.
• Adjustable Guard Time: Features adjustable guard time, enabling customization of tone recognition parameters to suit specific application requirements.
• Power-Down and Inhibit Modes: Offers power-down mode to minimize power consumption when not in use and inhibit mode to prevent detection of certain tones, enhancing control over operation.
• Central Office Quality: Meets stringent performance standards, ensuring reliable operation in telecommunications applications.