New Capacitive Touchscreen Controllers with SPI and I2C Interfaces for Home Appliances and Medical Designs

12 October 2021 - 0 Comments

Capacitive Touchscreen Controllers from Microchip

Microchip has extended its capacitive maXTouch touchscreen controller family with MXT448UD-HA and MXT640UD-HA controllers for harsh and noisy environments where electromagnetic interference can be caused by conveyer belts, power rails, or assembly machinery. These new controllers are also compliant with the IEC61000-4-6 Class A specification for conducted noise immunity up to 10 Vrms (level three for industrial use) and extend the Class B portfolio of devices beyond 10 inches. Moreover, these controllers provide dedicated solutions for larger screen sizes as well as scalability to customers.

These new touchscreen controllers come with two serial interfaces (SPI and I²C) that operate simultaneously allowing redundancy in a design through the integration of safety features, such as individual communication between the touchscreen controllers to the host microprocessor (MPU) in addition to a safety microcontroller (MCU). The unique architecture of the controllers shortens time to market and reduces development costs by allowing all safety-critical firmware to be developed on a dedicated safety-certified MCU.

Features

IEC 61000-4-6, 10Vrms, Class A (normal touch operation) conducted noise immunity
Scaled Deltas (remove false touches while cleaning with bleach or Windex)
Supports multi finger thick glove (5mm) touch
Supports thick lenses up to 10mm glass
Adaptive Sensing (Self and Mutual cap)
Communication via I2C interface
Supports up to 10 concurrent touches in real time with touch area reporting
Superior moisture performance
High voltage option via internal voltage pump to increase signal to noise ratio (SNR)
Operating temperature range of -40 to +85˚C
Package: 88-ball UFBGA
Comprehensive evaluation kit including touch sensor

Applications

Industrial applications
Home appliances
Medical designs

Availability

The two new devices (ATMXT448UD-CCUHA1, ATMXT640UD-CCUHA1) for home appliances are available in volume production starting at $2.40 for the ATMXT448UD part in 10,000-unit quantities.