BU8871F-E2

Overview

The BU8871F-E2 is a DTMF receiver IC developed for telephone answering machines. It converts 16 types of DTMF signals into 4-bit binary serial data. The device features a wide dynamic range of 45dB with internal AGC, eliminating the need for an external input amplifier. It supports a 4.19MHz crystal resonator and allows guard time control via a host microcontroller. Input pins include hysteresis on the ACK pin. Recommended operating conditions specify a supply voltage (VDD) of 5.0V.

Feature Summary

• Internal automatic gain control provides a 45dB dynamic range without external amplification
• Outputs decoded DTMF signals as 4-bit binary serial data
• Guard time functionality is controllable through a host microcomputer interface
• ACK input pin is equipped with hysteresis to improve signal stability

Applications

• Telephone answering machines

Procurement Notes

Verify the component designation against official Rohm Semiconductor documentation to confirm the specific suffix and revision level. Ensure that the ordering information matches the exact package type and manufacturing status required for the design. Cross-reference the datasheet version date to ensure all electrical characteristics and application notes are current before finalizing procurement specifications.

Selection Notes

Select this component for designs requiring direct DTMF decoding without intermediate amplification stages. The internal AGC simplifies the front-end circuit by removing the need for external variable gain amplifiers. Consider the requirement for a 4.19MHz clock source when designing the oscillator circuit. Verify that the host microcontroller can handle the serial data output protocol and ACK pulse timing requirements defined in the specification.

Part Context

The BU8871F belongs to Rohm's communication IC portfolio, specifically designed for telephony applications. It serves as a dedicated decoder for dual-tone multi-frequency signaling systems. The integration of digital detection and steering circuits allows for compact system designs in consumer electronics where space and power consumption are critical constraints.

Replacement Considerations

No public confirmed substitute part numbers are available.