TD223B Touch-Detection IC: Parameters & Application

Published: · Category: Application Note

TD223B is a single-channel, self-calibrating capacitive touch-detection IC in an SOT-23-6 package, designed to replace traditional mechanical keys and membrane switches. It integrates an LDO regulator and a self-calibration circuit, and detects finger touches by sensing electrode capacitance changes. Four output modes are supported (momentary-high / latched-high / momentary-low / latched-low), and it can drive LEDs, transistors or MCU pins directly. With very few external components and sensitivity adjustable via an external capacitor, it suits low-cost touch-key applications such as smart lighting, appliance panels, consumer electronics and toys.