AT42QT1070 Series

Catalog

TOUCH SENSOR CAPACITIVE 7 KEY 1.8V TO 5.5V SMD 20-PIN VQFN T/R

Part	LED Driver Channels [Max]	Voltage - Supply [Min]	Voltage - Supply [Max]	Operating Temperature [Max]	Operating Temperature [Min]	Type	Number of Inputs	Package / Case	Mounting Type	Proximity Detection	Supplier Device Package	Interface
Microchip Technology AT42QT1070-MMHR	5	1.8 V	5.5 V	85 °C	-40 °C	Buttons	7	20-VFQFN Exposed Pad	Surface Mount		20-VQFN (3x3)	I2C

Catalog

Key Features

• + Comms mode

• + Standalone mode

• + Comms mode: 1 – 7 keys (or 1 – 6 keys plus a Guard Channel)

• + Standalone mode: 1 – 4 keys plus a fixed Guard Channel on key 0

• + Number of I/O Lines in Standalone mode: 5 outputs

• + Technology: Patented spread-spectrum charge-transfer

• + Key Outline Sizes: 6 mm x 6 mm or larger (panel thickness dependent); widely different sizes and shapes possible

• + PCB Layers Required: One

• + Electrode Materials: Etched copper; Silver; Carbon; Indium Tin Oxide (ITO)

• + Panel Materials: Plastic; Glass; Composites; Painted surfaces (low particle density metallic paints possible

• + Panel Thickness: Up to 10 mm glass; Up to 5 mm plastic (electrode size dependent)

• + Comms mode: individually settable via simple commands over I2C-compatible interface

• + Standalone mode: settings are fixed

• + I2C -compatible slave mode (400 kHz)

• + Discrete detection outputs

• + Signal Processing:

• + Self-calibration

• + Auto drift compensation

• + Noise filtering

• + Adjacent Key Suppression® (AKS®) – up to three groups possible

• + Power Supply: 1.8 V – 5.5 V

• + 14-pin SOIC RoHS compliant IC

• + 20-pin VQFN RoHS compliant IC

Description

The AT42QT1070 (QT1070) is a digital burst mode charge-transfer capacitive sensor driver. The device can sense from one to seven keys, dependent on mode. The QT1070 has the optimized architecture where no external components are required and only 1-pin per channel. It includes all signal processing functions necessary to provide stable sensing under a wide variety of changing conditions, and the outputs are fully debounced. The QT1070 modulates its bursts in a spread-spectrum fashion in order to heavily suppress the effects of external noise, and to suppress RF emissions. The QT1070 use a dual-pulse method of acquisition. This provides greater noise immunity and eliminates the need for external sampling capacitors, allowing touch sensing using a single pin.