QT100A-ISMG

Overview

The QT100A-ISMG is a single-channel digital touch sensor IC utilizing patented spread-spectrum charge-transfer technology. It operates within a supply voltage range of 2.0V to 5.5V, consuming 6.5µA at 2.0V in low power mode. The device features an active-high digital output and supports Fast, Low Power, and Sync run modes. It includes internal self-calibration, drift compensation, and noise filtering. The component is housed in a 10-pin MSOP package with a Moisture Sensitivity Level (MSL) rating of 1.

Feature Summary

• Patented spread-spectrum charge-transfer technology for stable sensing
• Internal signal processing including self-calibration and auto drift compensation
• Configurable run modes: Fast, Low Power, and external Sync synchronization
• Active-high digital output with HeartBeat health indicator functionality

Applications

• Control panels and consumer appliances
• Toys and lighting controls
• Mechanical switch or button replacement

Procurement Notes

Verify the specific ordering suffix ISMG corresponds to the 10-MSOP package variant with MSL1 rating as documented in the official datasheet. Confirm that the supplier provides the original manufacturer documentation to ensure the component matches the specified electrical characteristics and pinout configuration.

Selection Notes

Select this component when a single-channel capacitive touch interface is required. Ensure the application panel thickness and dielectric constant are compatible with the recommended sample capacitor range of 2nF to 50nF. Verify that the system power supply remains stable between 2.0V and 5.5V to maintain proper operation.

Part Context

The QT100A is designed to replace the earlier QT100 model while offering behavioral compatibility. The ISMG suffix specifically denotes the 10-pin MSOP package option, distinct from the 6-WSON variant. This family utilizes QTouch technology for human-machine interfaces requiring robust proximity and touch detection capabilities.

Replacement Considerations

The QT100A serves as a direct replacement for the QT100. When converting designs, note that the 6-WSON package requires attention to the bottom center pad grounding to prevent shorts, whereas the 10-MSOP variant does not share this specific footprint constraint.

FAQ

How does the QT100A handle signal drift?

The device employs asymmetric drift compensation where the reference level tracks the raw signal slowly during non-detection states. It compensates faster for decreasing signals than increasing ones to prevent false triggers from approaching objects.

What is the function of the SYNC pin?

The SYNC pin determines the operating mode. Holding it high enables Fast mode, holding it low enables Low Power mode, and applying an external waveform synchronizes the device to an external clock source to prevent cross-interference.

How is the HeartBeat™ feature utilized?

The HeartBeat™ feature places the output pin into a three-state mode for 15µs before every measurement burst. This pulse can be sampled by a microcontroller or counter to verify that the sensor is operating correctly without affecting normal touch detection.