QuickSense™ Charge-Timing CDC Sensing Technology

The Silicon Labs patent-pending QuickSense SAR Charge-Timing Capacitance to Digital Converter (CDC) enables the industry’s fastest CDC without sacrificing sensitivity performance.

The unique hardware implementation of the CDC is capable of measuring capacitance on a wide range of materials including the following:

• Printed circuit board
• Flex circuit
• ITO on glass and film

The innovative circuit employs a pair of current sources driving two separate capacitors:

1. The CDC’s internal reference capacitor denoted as C_REF
2. External C_SENSOR

The current source denoted as I_REF is a fixed current used to drive the C_REF capacitor to provide a constant ramp voltage.

The second current source denoted I_SENSOR sources a variable current to the sensor capacitor. After each measurement cycle the SAR logic will change the value of I_SENSOR, attempting to get the ramp rate the same as the reference capacitor. The circuit also offers a powerful wake-on-touch feature.

Capacitive Touch Sense Overview

Learn how to implement the Charge-Timing Capacitive Sensing technology.

 Available Products

* Denotes maximum value in family
** CT denotes Charge-Timing CDC