BU21078FV-E2

Overview

The BU21078FV-E2 is a capacitive sensor controller IC designed for switch operation, featuring 12 capacitive sensor ports and support for up to 36 matrix switches. It operates on a single power supply ranging from 3.0 V to 5.5 V with a typical operating current of 3.5 mA. The device includes an integrated LED controller with PWM functionality for brightness control. Communication with the host is handled via a 2-wire serial bus interface compatible with the I2C protocol. Automatic self-calibration compensates for external noise and temperature drift, ensuring stable detection results.

Feature Summary

• Supports simple and matrix switch configurations with automatic self-calibration for environmental stability.
• Integrates an LED controller with PWM timers for fade-in/fade-out brightness adjustment.
• Utilizes a 2-wire serial bus interface (I2C compatible) for host communication and interrupt-driven status updates.

Applications

• Appliances requiring multiple switch inputs
• Information appliances such as printers
• AV appliances including digital TVs and HDD recorders
• Notebook PCs

Procurement Notes

Verify component authenticity through authorized distributors or direct manufacturer channels. Confirm RoHS compliance status and check for obsolescence notices, as this part may be discontinued. Ensure the SSOP-B28 package dimensions match your PCB footprint requirements before finalizing procurement decisions.

Selection Notes

Select this model when 12 sensor channels are required in a surface-mount SSOP-B28 package. Compare against the BU21078MUV if a smaller VQFN package is preferred. Ensure the host system supports I2C communication and can handle the active-high interrupt signals generated by the controller during touch events.

Part Context

This component belongs to the ROHM BU2107x series of capacitive switch controllers. It shares core architecture with the BU21072MUV and BU21078MUV but differs in package type and channel count. The FV suffix specifically denotes the SSOP-B28 packaging format used in this variant.

Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided documentation. Consider evaluating the BU21078MUV for pin-compatible alternatives if package constraints allow, though verification of specific electrical characteristics is required.

FAQ

How does the BU21078FV-E2 handle environmental changes?

The IC features automatic self-calibration that detects external noise and temperature drift, adjusting parameters to maintain stable switch detection results without periodic polling.

What is the maximum number of matrix switches supported?

The BU21078FV-E2 supports a maximum of 36 matrix switches configured by 6x6 sensors.

Can the LED outputs be controlled independently?

Yes, each LED port can be assigned to one of four PWM timers, allowing independent control of rising, falling, and lighting periods for brightness adjustment.