QT60040-S

Overview

The QT60040 is a CMOS charge-transfer sensor IC designed for matrix touch controls, supporting up to four keys in a 4x1 scanned configuration. It operates on a single 2.5V to 5.5V power supply with typical current consumption of 0.6mA at 3V and 1.5mA at 5V. The device features four active-high outputs capable of sensing up to two simultaneous key presses. It requires only one external sampling capacitor (typically 22nF to 220nF) for operation. The IC includes self-calibration, drift compensation, and detection integration algorithms to ensure stability under varying environmental conditions.

Feature Summary

• Transverse charge-transfer technology using a 4x1 matrix requiring only one shared sampling capacitor
• Automatic recalibration after 10 or 60 seconds of continuous detection via OPT2 pin selection
• Asymmetric drift compensation algorithm that tracks raw signal changes while maintaining sensitivity
• Detection integrator requiring three consecutive samples to confirm a touch event

Applications

• Automotive controls
• PC and peripheral controls
• ATM machines
• Appliance controls
• Security keypads

Procurement Notes

Verify the specific suffix against the ordering information table to confirm package type and temperature range. The -IS suffix indicates a 14-pin SOIC package rated for -40°C to +85°C. The -D suffix indicates a 14-pin DIP package rated for 0°C to +70°C. Ensure the required operating environment aligns with the selected suffix specifications before procurement.

Selection Notes

Select the -IS variant for industrial environments requiring operation down to -40°C. Select the -D variant for standard commercial applications within the 0°C to +70°C range. Configure OPT1 to restrict sensing to one key or allow two-key rollover based on application requirements. Configure OPT2 to set the recalibration timeout to either 10 seconds or 60 seconds. Use plastic capacitors such as polyester or PPS for the sampling capacitor Cs to ensure optimal stability.

Part Context

The QT60040 utilizes Quantum Research Group's patented transverse charge-transfer technology. This method minimizes scan lines and external components compared to older technologies that often require one IC per key. The design allows for cost-competitive solutions using common PCB materials without custom molded membranes, facilitating accelerated time to market for OEMs.

Replacement Considerations

Public confirmed substitute part numbers are not available in the provided documentation.