BU8874

Overview

The BU8874 is a DTMF receiver IC designed for telephone answering machines, converting 16 distinct DTMF signals into 4-bit binary serial data. It features a wide dynamic range of 45dB with internal AGC, eliminating the need for external input amplifiers. The device operates within a supply voltage range of 4.75V to 5.25V and consumes 2.2mA during operation. It supports power-down mode and allows guard time control via a host microcontroller through the ACK pin. The component is housed in an 8-pin DIP package and functions with a 4.19MHz crystal resonator.

Feature Summary

• Converts DTMF signals into 4-bit binary serial data
• Features 45dB dynamic range with internal AGC
• Supports power-down mode for energy efficiency
• Allows guard time control via host microcontroller

Applications

• Telephone answering machines

Procurement Notes

Verify component authenticity and datasheet revision status before integration. Confirm that the specific manufacturing lot meets required environmental standards. Check for end-of-life notifications or discontinuance alerts from ROHM Semiconductor. Ensure compatibility with existing PCB footprint and soldering profiles. Validate supply chain sources for reliability.

Selection Notes

Select this component for applications requiring direct DTMF decoding without external amplification due to its wide dynamic range. Ensure the design accommodates an 8-pin DIP package and provides space for a 4.19MHz crystal resonator. Verify that the host microcontroller can interface with the ACK pin for timing control. Consider the power-down feature if battery life or low-power states are critical.

Part Context

The BU8874 belongs to ROHM Semiconductor's line of communication ICs specifically tailored for telecom interfaces. It is part of the BU8874 family, which includes variants like the BU8874F in different packages. This series addresses the need for compact, efficient DTMF reception in legacy and modern telephony equipment.

Replacement Considerations

BU8874FE2