TC646VUA

Overview

The TC646VUA is a switch-mode fan speed controller designed for brushless DC fans, manufactured by Microchip Technology. It operates within a supply voltage range of 3 V to 5.5 V and draws a typical operating current of 500 uA. The device features an output current capability of 5 mA and functions across a temperature range from 0°C to +85°C. Packaged in an 8-pin MSOP format for surface mount installation, it integrates FanSense technology for fault detection and includes shutdown capabilities for power management.

Feature Summary

• Integrates FanSense technology for detecting fan failure and aiding system testing
• Provides temperature-proportional fan speed control via pulse width modulation
• Includes a shutdown mode to support energy-efficient system designs

Applications

• Brushless DC fan speed control in electronic equipment
• Acoustic noise reduction systems requiring temperature-dependent speed adjustment
• Systems utilizing low-cost NTC or PTC thermistors for thermal sensing

Procurement Notes

Verify the specific suffix 'VUA' against the official Microchip datasheet to confirm package type and temperature grade. Ensure compatibility with the required fan voltage, as the output is independent of the controller supply. Confirm RoHS compliance status through the manufacturer's environmental documentation before finalizing procurement specifications.

Selection Notes

Select this component when designing systems that require integrated thermal sensing and PWM fan control without external microcontrollers. It is suitable for applications needing fault detection to prevent fan failure. Consider the 8-pin MSOP package for space-constrained layouts. Verify that the 5 mA output current meets the drive requirements of the target brushless DC fan.

Part Context

The TC646 belongs to the TC646 series of fan controllers from Microchip Technology. This series focuses on providing efficient, software-free solutions for managing brushless DC fans. The device simplifies design by combining speed control, fault detection, and thermal management into a single integrated circuit, reducing the need for additional discrete components.

Replacement Considerations

The TC646BEUA is a documented alternative within the same family, offering similar functionality but potentially differing in operating temperature range or packaging configuration. Verify electrical parameters and pinout compatibility before substitution.