BU8307CF-E2

Overview

The BU8307CF-E2 is a large-scale integrated circuit designed as a pulse and tone dialer for telephone sets. It integrates both dialing modes on a single chip, supporting redial functionality for up to 32 digits in pulse mode or 31 digits in tone mode. The device operates within a voltage range of 2.5V to 5.5V, allowing direct powering by line current. Key electrical characteristics include a DTMF frequency deviation of +0.15% and -0.08%, a keytone output frequency of 1193Hz with a duration of 34ms, and selectable hooking times of 84ms or 607ms. Pulse break ratios are configurable at 60% or 67%. The component utilizes an internal oscillator connected via external resonators and features multiple control pins for mode selection and keypad interfacing.

Feature Summary

• Integrates both pulse and tone dialing capabilities on a single chip for flexible operation.
• Supports direct powering from line current due to a wide operating voltage range.
• Includes built-in memory for redialing up to 32 digits depending on the selected mode.
• Conforms to telecommunications standards across multiple regions including Japan, America, and Europe.

Applications

• Telephones
• Cordless telephones

Procurement Notes

Verify the specific suffix 'E2' against the manufacturer's official documentation to confirm environmental compliance status and lead time requirements. Ensure the ordering code matches the exact package type and pin configuration required for the design. Cross-reference the datasheet revision date to confirm the validity of the electrical parameters and application circuits provided.

Selection Notes

Select this component when a combined pulse and tone dialer solution is required for standard telephone applications. Consider the 2.5V to 5.5V operating range for compatibility with line-powered designs. Verify that the external crystal resonator specifications align with the OSCIN/OSCOUT pin requirements. Evaluate the keypad matrix size support, which accommodates standard 3x4 or 4x4 layouts.

Part Context

The BU8307CF-E2 belongs to the BU8307 series of communication ICs manufactured by ROHM Semiconductor. This series is specifically engineered for use in telephone set dialing mechanisms. The CF variant typically denotes a specific package or temperature grade within the broader product family, sharing core functional blocks with the BU8307CS model while potentially differing in physical packaging or regional certification details.

Replacement Considerations

The BU8307CS is a functionally equivalent part within the same series. Verify if the package type and suffix differences impact mechanical integration or regulatory compliance before substitution.

FAQ

How many digits can be redialed in tone mode?

In tone mode, the memory uses one digit to store the mode information, allowing a maximum of 31 digits to be redialed.

What is the keytone output frequency?

The KEYTONE pin outputs a confirmation tone at a frequency of 1193Hz with a duration of 34ms for valid key inputs.

Can the mode be switched during dialing?

Yes, switching from pulse mode to tone mode can be performed once during an off-hook state by pressing the T key or setting the MODEIN pin appropriately.