QT401-ISSG

Overview

The QT401-ISSG is a QSlide touch slider IC designed for 1-dimensional position sensing in human-machine interfaces. It operates on a single supply voltage ranging from 2.5V to 5.5V and utilizes a resistive sensing strip between two connection points to determine finger position. The device employs proprietary charge-transfer methods with spread-spectrum modulation for noise immunity. Positional data is output as a 7-bit binary integer (0-127) via an SPI slave interface. The component is housed in a 14-pin SOIC package, suitable for automotive, appliance, and lighting control applications.

Feature Summary

• Capacitive sensing using patented charge-transfer technology across a resistive element
• SPI slave-mode interface for host controller communication and configuration
• Spread-spectrum burst mode operation for superior electromagnetic compatibility
• Integrated self-calibration and automatic drift compensation capabilities

Applications

• Automotive interior controls such as speed or volume adjustments
• Appliance user interfaces including menu bars and exotic input forms
• Lighting control systems requiring dimming or preset selection
• Touch-screen overlays compatible with Indium Tin Oxide (ITO) displays

Procurement Notes

Verify the ordering suffix ISSG confirms the 14-pin SOIC package and industrial temperature range specifications. Ensure the procurement source provides original manufacturer documentation to confirm compliance with RoHS standards and lead-free material requirements. Cross-reference the part number against official Microchip Technology databases to validate authenticity and avoid counterfeit components during acquisition.

Selection Notes

Select this component when a linear or arc-shaped capacitive slider interface is required without moving mechanical parts. The device is appropriate for designs needing real-time finger tracking or discrete button emulation on a continuous strip. Consider the power supply constraints, as the unit requires a clean 2.5V to 5.5V source. Evaluate the panel thickness and dielectric constant, as these factors influence the necessary external sample capacitor values for optimal positional granularity.

Part Context

The QT401 belongs to the QSlide family of one-dimensional position sensors developed by Quantum Research Group, now part of Microchip Technology. This series focuses on creating simple, inexpensive human interface solutions using passive resistive strips. The QT401 specifically enables designers to implement speed controls, volume sliders, and menu inputs on appliances or LCD overlays, distinguishing itself through its unique charge-transfer sensing methodology.

Replacement Considerations

No public confirmed substitute part numbers are available in the provided documentation. Designers should evaluate functional equivalents based on SPI interface compatibility, voltage range, and package dimensions if substitution is necessary.

FAQ

How does the QT401 handle environmental drift?

The device features automatic drift compensation that adjusts reported data under host control. In free-run mode, it compensates at a rate of one count per 180 acquisition bursts. Host commands can also trigger immediate recalibration to correct for temperature or humidity changes.

What is the resolution of the position output?

The QT401 outputs a 7-bit binary integer representing position from 0 to 127. This value corresponds to the physical location along the slider element, with end points calibrated to match the mechanical limits of the resistive strip.

Can the QT401 be used as a proximity sensor?

Yes, the PROX output pin goes high when a hand is detected in free space near the slider. This feature allows the device to wake up a product from sleep mode or detect presence without direct contact with the slider element.