QT60040-DG

Overview

The QT60040-DG is a CMOS charge-transfer sensor IC designed for matrix touch controls. It detects up to four keys in a 4x1 scanned matrix, projecting through dielectrics up to 6mm thick. The device features active-high outputs and supports simultaneous sensing of two keys. It operates on a single power supply ranging from 2.5V to 5.5V. Key specifications include a maximum continuous pin current of ±20mA, an input leakage current of ±1µA, and a high output voltage of Vdd-0.7V. The supply current ranges from 0.4mA at 3V to 1.5mA at 5V. The package is a 14-pin SOIC.

Feature Summary

• Transverse charge-transfer technology enables detection through various dielectric materials without requiring custom molded membranes.
• Integrated self-calibration and asymmetric drift compensation algorithms ensure stable operation under changing environmental conditions.
• Configurable Max On-Duration feature allows automatic recalibration after 10 or 60 seconds of continuous key contact.

Applications

• Automotive control panels
• ATM machine interfaces
• Industrial keyboards
• Security keypads

Procurement Notes

Verify the specific suffix against the manufacturer's ordering guide to confirm the package type and temperature range. Ensure the component matches the required operating environment specifications before integration into the design.

Selection Notes

Select this component for applications requiring robust touch sensing through thick dielectrics with minimal external circuitry. Evaluate the need for simultaneous multi-key detection capabilities and verify that the 14-pin SOIC package fits the board layout constraints.

Part Context

This part belongs to the QT60040 family of digital charge-transfer sensors developed by Quantum Research Group. The family includes variants such as the QT60040-IS for industrial temperature ranges and the QT60040-D for commercial ranges, all sharing the same core sensing architecture.

Replacement Considerations

Direct replacements within the same family include the QT60040-IS (industrial grade) and QT60040-D (commercial grade). Verify pin compatibility and temperature ratings when substituting these variants.

FAQ

How does the QT60040 handle drift over time?

The device uses an asymmetric drift compensation algorithm that tracks the raw signal slowly while no detection is active, adjusting thresholds in real-time to prevent false detections.

What is the maximum number of keys that can be sensed simultaneously?

The IC can sense any two keys at the same time. A jumper option allows restricting this to only one key if desired.

What external components are required for operation?

Only a single inexpensive sampling capacitor (Cs) is required. Typical values range from 22nF to 220nF, with 47nF being a common starting point.