Microchip MTCH3380P and MTCH3240P Touch Controllers Offer Parallel Sensing

Microchip MTCH3380P and MTCH3240P Turnkey Touch Controllers

Microchip Technology Inc. has released its first turnkey touch controllers offering parallel sensing for buttons, sliders, and wheels in appliances and outdoor and industrial applications. The two new members of the capacitive-touch family offer enhanced touch sensitivity and noise immunity, enabling touch sensing through thick cover materials and gloves. MTCH3380P and MTCH3240P controllers are targeted at applications where equipment manufacturers are looking to reduce costs by replacing displays with human machine interfaces using illuminated capacitive-touch buttons, sliders, and wheels.

The downside is that these conventional interfaces frequently involve a substantial quantity of touch sensors, which can influence the standard acquisition duration and signal-to-noise ratio (SNR). This functionality is accomplished with 12 on-chip analog-to-digital converters (ADCs) in parallel. The MTCH3380P and MTCH3240P controllers combat the touch-sensing limitations corresponding with display-free interfaces by achieving fast touch acquisition and high SNR, guaranteeing reliable and rapid functioning even in demanding use cases.

MTCH3240P Controller

Microchip MTCH3380P and MTCH3240P Touch Controller Specifications:

• Touch-Sensing Technology: Microchip’s patented charge-transfer acquisition engine combines pipelined analog sensing with digital signal processing for fast, reliable touch detection.
• Capacitive Touch Sensing:
  • Mutual-capacitance keys: Supports up to 64 keys on the MTCH3380P and 32 keys on the MTCH3240P.
  • Self-capacitance keys: Handles up to 38 keys on the MTCH3380P and 24 keys on the MTCH3240P.
  • Sliders and wheels: Support up to eight groups on the MTCH3380P and six groups on the MTCH3240P.
  • Sensing modes: Single-ended mutual, point-to-point (P2P) mutual, single-ended self, and P2P self-capacitance sensing.
  • Panel compatibility: Accommodates glass panels up to 6 mm thick and plastic panels up to 3 mm thick.
• Noise Immunity and Interference Suppression:
  • Withstands noise levels of up to 240 VPP across the 1 Hz–1 kHz frequency range under no-touch conditions.
  • Incorporates suppression mechanisms for electrical noise and power-line interference.
  • Meets IEC 61000-4-6 Class A conducted-noise immunity requirements at 10 Vrms.
• Functional Safety and Security:
  • Functional safety: UL/IEC 60730 Class B-ready design with power-on and periodic self-diagnostics.
  • Data encryption: AES-128 encryption protects configuration parameters and object protocol messages.
  • Firmware authentication: Built-in authentication mechanisms help detect firmware tampering.
• Host Connectivity:
  • Interface: I²C client interface with Standard-mode (100 kHz), Fast-mode (400 kHz), and Fast-mode Plus (1 MHz) support.
  • Interrupt signaling: Dedicated CHG line for host notifications.
• Additional Features:
  • Adjacent Key Suppression (AKS) technology for improved multi-key discrimination.
  • 64-byte custom data storage without checksum protection.
  • Integrated PWM output for display backlight control, audible buzzer operation, or haptic feedback on the MTCH3380P.
• Power Supply and Operating Modes:
  • Digital supply (VDD): 3.3 V nominal.
  • I/O supply (VDDIO): 1.8 V to 3.3 V nominal.
  • Additional analog supply: 3.3 V analog supply and an internal voltage doubler generating a 6.6 V sensor-drive voltage, available exclusively on the MTCH3380P.
  • Power management: Configurable active and idle modes with automatic wake-up upon touch detection.
• Package and Dimensions:
  • MTCH3380P: 56-pin XQFN package measuring 6 × 6 × 0.4 mm.
  • MTCH3240P: 38-pin XQFN package measuring 4 × 4 × 0.35 mm.
  • Pin pitch: 0.35 mm for both devices.
  • Operating Temperature Range: −40°C to +105°C.

MTCH3380P Controller

MTCH3380P supports up to 38 sensors in self-capacitance mode and 64 sensors in mutual-capacitance mode whereas MTCH3240P supports up to 24 and 32 sensors respectively, without the acquisition-time penalties associated with high sensor counts. With support for customer driven IEC 60730 Class B functional safety certification, MTCH3380P and MTCH3240P devices aid manufacturers in working towards regulatory compliance. The devices are rated for normal operating conditions up to 105oC. Superior touch sensitivity and noise immunity allow for dependable touch detection by means of thick cover materials and gloves. This makes them suitable for a range of in-home appliances such as ovens, cooktops, refrigerators, and washing machines as well as outdoor applications including EV chargers, parking meters, and kiosks that require durable protective covers and reliable operation in cold-weather conditions.

Microchip’s touch-sensing ecosystem and turnkey controllers are designed to provide the hardware, software and development resources needed to accelerate design, evaluation and testing. Support includes the mTouch Studio development environment and evaluation hardware, including host drivers for Linux and Zephyr. The touch controllers supports configuration, tuning, and testing through the mTouch Studio utility. 

Now available, prices start at $1.06 each for the MTCH3380P and $0.80 each for the MTCH3240P in 10,000-unit quantities. Refer to the website and press release for additional information about Microchip’s portfolio of turnkey capacitive-touch controllers.