Microchip Technology MTCH108-I/SS

Overview

MTCH108-I/SS from Microchip Technology is an 8-channel capacitive proximity and touch controller with active guarding, operating from 2.05V to 3.6V over –40°C to +85°C, featuring configurable sensitivity via MTSA pin and low-power mode selection via MTPM pin. It delivers reliable detection in lighting controls, appliance interfaces, and display activation systems using open-drain digital outputs.

For engineers reviewing the MTCH108-I/SS datasheet, MTCH108-I/SS pinout, MTCH108-I/SS application, or MTCH108-I/SS equivalent, this device supports 8 independent sensor inputs with one assignable as active guard, offers adjustable noise suppression, and enables rapid integration into space-constrained consumer and industrial HMI designs without firmware overhead.

Technical Context

The MTCH108-I/SS implements hardware-based capacitive sensing with multi-stage active noise suppression filters and automatic environmental compensation. Its architecture supports simultaneous monitoring of eight sensor inputs, with one (MTI2) configurable as active guard output to shield adjacent sensor traces from EMI and power plane coupling.

Sensitivity is set by analog voltage on MTSA (0–VDD), enabling linear adjustment across sensor geometries; low-power mode is selected by grounding MTPM, trading response speed for reduced current draw. All eight MTOx outputs are open-drain, requiring external pull-ups and asserting low on detection.

Key Specifications

Pinout & Package

MTCH108-I/SS is housed in a 20-lead SSOP package (body width 5.3mm, pitch 0.65mm), optimized for automated assembly and compact PCB layouts in consumer and appliance applications.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar capacitive proximity/touch controller applications.

Compared with MTCH105-I/SS, MTCH108-I/SS adds three more sensor channels and outputs while retaining identical power, guarding, and packaging; versus CY8CMBR2016A-SSXQ, it eliminates firmware dependency but trades configurability for plug-and-play simplicity.

Availability

MTCH108-I/SS is available at Aetrix Electronics and suitable for lighting controls, appliance interfaces, and display activation systems requiring stable component supply, long-term manufacturability, and RoHS-compliant sourcing.

Supply support for MTCH108-I/SS includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog, interface, and touch-sensing solutions with ISO/TS 16949-certified manufacturing.

The MTCH108-I/SS belongs to Microchip's mTouch® family of self-contained capacitive controllers, designed specifically for cost-sensitive, firmware-free human-machine interfaces in consumer, industrial, and appliance markets.

FAQ

What is the primary function of the MTCH108-I/SS in a system?

The MTCH108-I/SS serves as a standalone 8-channel capacitive proximity and touch controller that converts changes in sensor capacitance into discrete active-low digital outputs without requiring host MCU firmware. Each MTIx input monitors a dedicated electrode, and corresponding MTOx pins assert low upon detection-making MTCH108-I/SS ideal for direct connection to logic gates, microcontroller GPIOs, or LED drivers in lighting, appliance, and display applications.

How does the active guard feature work on the MTCH108-I/SS?

The MTCH108-I/SS implements active guarding on the MTI2/Guard pin: when enabled via the MTO2/GC pin, it drives a synchronized waveform matching the phase of the guarded sensor signal, minimizing voltage differential and reducing capacitive coupling from noise sources. This feature is confirmed in the DS40001780A datasheet and improves noise immunity for MTI2 and adjacent traces-critical in high-density PCBs near switching regulators or AC mains.

Can the MTCH108-I/SS operate from a 3.3V supply?

Yes, the MTCH108-I/SS operates across 2.05V to 3.6V, making 3.3V a fully supported and commonly used supply voltage. At 3.3V, all specifications-including output drive strength, sensitivity range, and temperature performance-remain within datasheet limits. The device's VDD pin must be decoupled with a 100nF ceramic capacitor placed close to the package.

What is the role of the MTSA pin on the MTCH108-I/SS?

The MTSA pin on the MTCH108-I/SS sets global sensitivity via an analog voltage: 0V yields maximum sensitivity (smallest detectable capacitance change), VDD yields minimum sensitivity, and intermediate voltages provide linear scaling. This allows designers to tune detection thresholds for different overlay materials, thicknesses, or environmental conditions without modifying firmware or layout-confirmed in the "PIN DESCRIPTION" section of DS40001780A.

Is the MTCH108-I/SS pin-compatible with other devices in the MTCH10X family?

The MTCH108-I/SS uses a 20-pin SSOP package with a defined pinout documented in Table 5 of DS40001780A. While MTCH105-I/SS shares the same 20-pin TSSOP/QFN footprint and overlapping pin assignments for VDD, VSS, MTI0–MTI4, MTO0–MTO4, MTSA, MTPM, and MTO2/GC, MTCH108-I/SS extends the mapping to MTI5–MTI7 and MTO5–MTO7. Thus, it is not pin-compatible with MTCH102 or MTCH105 in full-channel mode-but partial compatibility exists for designs using only the first five channels.