The QT140 / QT150 charge-transfer (“QT”) QTouch ICs are self-contained digital controllers capable of detecting near-proximity or touch on 4 or 5 electrodes. They allow electrodes to project independent sense fields through any dielectric like glass, plastic, stone, ceramic, and wood. They can also turn metal-bearing objects into intrinsic sensors, making them responsive to proximity or touch. Each of the channels operates independently of the others, and each can be tuned for a unique sensitivity level by simply changing its sample capacitor value. The devices are designed specifically for human interfaces, like control panels, appliances, gaming devices, lighting controls, or anywhere a mechanical switch or button may be found; they may also be used for some material sensing and control applications.
QT140 and QT150 are charge‑transfer QTouch sensor ICs that provide independent sensing on 4 or 5 electrodes. Each channel has its own logic output, adjustable sensitivity, and optional features such as Adjacent Key Suppression (AKS) and a Sync pin for multi‑chip synchronization.
The devices operate from a single low‑cost capacitor per channel, support 3 V to 5.5 V supply, and include built‑in drift compensation, detection integrator, and configurable Max On‑Duration timers. They are offered in SSOP‑28 and DIP‑28 packages for a range of temperature grades.
| Supply voltage | 3 V to 5.5 V |
|---|---|
| Supply current | ≈5 mA |
| Temperature range (QT140‑D / QT150‑D) | 0 °C to +70 °C |
| Temperature range (QT140‑AS / QT150‑AS) | -40 °C to +105 °C |
| Package types | SSOP‑28, DIP‑28 |
| Response time | 99 ms at 10 MHz clock |
| Max On‑Duration options | 10 s, 60 s, infinite |
| Threshold level | 6 counts |
| Hysteresis | 2 counts |
| Sync pin function | Multi‑chip synchronization |
The devices operate from a single supply of 3 V to 5.5 V and draw about 5 mA.
The Max On‑Duration feature provides strap‑selectable timeouts of 10 s, 60 s, or infinite.
AKS™ (Adjacent Key Suppression) disables touch detection on neighboring keys to prevent false activations.