MTCH108-I/SS - 8-Channel Proximity/Touch Controller IC | Microchip
MPN: MTCH108/SS ✓ Active| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $1.85 | $1.85 |
| 10 | $1.66 | $16.60 |
| 100 | $1.42 | $142.00 |
| 500 | $1.18 | $590.00 |
| 1,000 | $0.96 | $960.00 |
MTCH108/SS Overview
A capacitive touch controller is a mixed-signal integrated circuit that measures capacitance changes caused by a user's finger on a sensor pad, converts the analog delta into a digital state, and outputs a clean logic-level signal. Within the broader semiconductor taxonomy, the MTCH108 sits in the hierarchy: capacitive touch controller -> touch screen / human-interface controller -> sensor IC -> mixed-signal semiconductor. It removes the firmware burden of touch processing by providing a hardware-only solution with no MCU programming required, making it ideal for low-MCU or pure-logic designs.
Key specifications include 8 simultaneous capacitive sensing inputs, an integrated guard-ring driver for moisture immunity, automatic calibration across sensitivity levels, and low active current suitable for battery-powered applications. The MTCH108 supports both proximity (hover) and direct-touch detection modes, enabling wake-on-approach behavior in IoT devices. The 20-pin SSOP package has standard 0.65 mm pitch and 5.30 mm body width for easy hand-soldering and visual inspection during prototyping.
Typical applications include consumer appliance control panels, industrial HMI keypads, automotive interior lighting controls, IoT smart-home touch buttons, and replacement of mechanical switches in sealed enclosures. The wide operating voltage range supports direct connection to 3.3 V rails commonly used by Microchip PIC and SAM microcontrollers, simplifying power-tree design.
When designing with the MTCH108, ensure the sensor pad geometry follows Microchip's layout guidelines to maximize SNR, and place a 100 nF decoupling capacitor within 5 mm of the VDD pin. The MTPM pin can be tied high for maximum sensitivity or low for lower power consumption depending on system requirements.
This page consolidates distributor stock, parametric drop-in alternatives (including the lower-channel MTCH102 and MTCH105), and practical PCB layout notes that complement - but do not replace - the manufacturer datasheet.
Drop-in alternatives for MTCH108/SS — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with MTCH108/SS (same form factor and footprint) — differing in Noise Suppression, Package, Number of Digital Outputs, Operating Temperature Range, Sensitivity Configuration.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
MTCH108T-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
MTCH108-I/GZ
✅ Drop-In✓ In Stock
$1.41 / Unit
View Datasheet →MTCH105-I/SS
✅ Drop-In📋 Reference alternative (not in catalog)
MTCH108/SS Maximum Ratings & Electrical Characteristics
| Product Type | Capacitive Proximity/Touch Controller |
| Number of Channels | 8 |
| Number of Digital Outputs | 8 (1 per channel) |
| Operating Voltage (VDD) | 2.05 V to 3.6 V |
| Operating Temperature Range | -40C to +85C (Industrial) |
| Sensitivity Configuration | MTSA pin (selectable) |
| Power Mode Configuration | MTPM pin (selectable) |
| Noise Suppression | Advanced optimization algorithm (on-die) |
| Proximity Detection | Yes (hover / wake-on-approach) |
| Direct Touch Detection | Yes (capacitive) |
| Guard-Ring Driver | Integrated (moisture immunity) |
| Automatic Calibration | Yes |
| Package | 20-pin SSOP (5.30 mm body, 0.65 mm pitch) |
| Mounting Type | Surface Mount |
| MSL Level | 1 |
| RoHS Status | Compliant |
| Lead-Free | Yes |
MTCH108/SS Pin Configuration
| Pin 1 | CH0 — Capacitive sensing channel 0 input |
| Pin 2 | CH1 — Capacitive sensing channel 1 input |
| Pin 3 | CH2 — Capacitive sensing channel 2 input |
| Pin 4 | CH3 — Capacitive sensing channel 3 input |
| Pin 5 | CH4 — Capacitive sensing channel 4 input |
| Pin 6 | CH5 — Capacitive sensing channel 5 input |
| Pin 7 | CH6 — Capacitive sensing channel 6 input |
| Pin 8 | CH7 — Capacitive sensing channel 7 input |
| Pin 9 | MTPM — Power mode select (high = max sensitivity, low = low power) |
| Pin 10 | MTSA — Sensitivity adjustment select |
| Pin 11 | OUT0 — Digital output for channel 0 (active high) |
| Pin 12 | OUT1 — Digital output for channel 1 (active high) |
| Pin 13 | OUT2 — Digital output for channel 2 (active high) |
| Pin 14 | OUT3 — Digital output for channel 3 (active high) |
| Pin 15 | OUT4 — Digital output for channel 4 (active high) |
| Pin 16 | OUT5 — Digital output for channel 5 (active high) |
| Pin 17 | OUT6 — Digital output for channel 6 (active high) |
| Pin 18 | OUT7 — Digital output for channel 7 (active high) |
| Pin 19 | VDD — Positive supply (2.05 V to 3.6 V) |
| Pin 20 | GND — Ground reference |
Typical Applications
MTCH108/SS is suitable for 6 applications: Consumer Appliance Control Panels, Industrial HMI Keypads, Automotive Interior Lighting and Seat Controls, IoT Smart-Home Touch Buttons, Replacement of Mechanical Switches in Sealed Enclosures, Audio/Video Equipment Front Panels.
Consumer Appliance Control Panels
The MTCH108-I/SS fits consumer appliance control panels because it provides 8 capacitive channels with hardware-only digital outputs and an integrated guard-ring driver that resists moisture and false triggers from wet fingers or splashed water. The 2.05 V to 3.6 V supply connects directly to a 3.3 V PIC or SAM MCU rail, simplifying the power tree in washing machines, dishwashers, and microwave ovens. The advanced on-die noise-suppression algorithm rejects interference from universal-motor brush noise and 50/60 Hz mains ripple, which are common in appliance environments. Designers save BOM cost by replacing 8 mechanical pushbuttons and their debounce RC networks with a single 20-pin SSOP IC and 8 sensor pads etched on the PCB.
Recommended
Industrial HMI Keypads
For industrial HMI keypads, the MTCH108-I/SS delivers 8 sealed capacitive buttons with no moving parts, eliminating ingress paths for dust and oil that would otherwise disable mechanical keypads. The -40C to +85C industrial temperature range covers most factory-floor environments, and the active-high outputs can drive optocouplers or low-side MOSFETs directly to switch 24 V industrial loads. The MTSA pin lets the engineer trade sensitivity for robustness, allowing fine adjustment to ignore thick operator gloves. Replacing 8 mechanical switches with one IC plus 8 copper pads reduces assembly time, eliminates tactile-switch wear-out failure modes, and gives a modern flat-panel aesthetic preferred in new HMI designs.
Recommended
Automotive Interior Lighting and Seat Controls
The MTCH108-I/SS works in non-safety automotive interior applications such as dome-light touch panels, seat-position memory buttons, and door-module mirror controls where 8 capacitive channels with simple digital outputs are sufficient. While the part is industrial-grade (not AEC-Q100), it is used in cabin environments that stay within -40C to +85C. The proximity-detection mode enables wake-on-approach lighting that illuminates the cabin as the driver's hand approaches, enhancing perceived quality. The on-die guard-ring driver rejects RF noise from the vehicle's CAN bus and infotainment system, which the datasheet documents as a key automotive-environment robustness feature.
Recommended
IoT Smart-Home Touch Buttons
The MTCH108-I/SS fits battery-powered IoT smart-home devices such as smart speakers, lighting dimmers, and security-panel keypads that need 8 capacitive buttons with low standby current and direct logic outputs. The MTPM power-mode pin can be toggled to put the device in low-power standby between user interactions, preserving battery life. The 3.6 V maximum supply matches a single Li-ion cell with headroom, eliminating the need for a separate regulator. The proximity (hover) mode enables wake-on-approach so a passing finger activates the device without requiring a mechanical press, which is ideal for sealed touch interfaces on outdoor smart locks and doorbells.
Recommended
Replacement of Mechanical Switches in Sealed Enclosures
The MTCH108-I/SS is a direct replacement for mechanical pushbuttons and toggle switches in sealed medical, outdoor, or food-service enclosures where crevices around mechanical switches collect contamination. Eight capacitive buttons on a flat panel are inherently sealed because the sensor pads live under a continuous overlay material - no holes, no gaskets, no moving parts. The IC's automatic self-calibration accommodates overlay thickness from 1 mm to 5 mm glass or acrylic, simplifying mechanical integration. Designers achieve IP65/IP67 ratings without redesigning the enclosure, and eliminate the dominant field-failure mode of mechanical-switch contact wear in high-cycle applications such as medical pump keypads or industrial scales.
Recommended
Audio/Video Equipment Front Panels
The MTCH108-I/SS works in audio/video equipment front panels where 8 capacitive buttons replace mechanical volume, source-select, transport, and preset keys for a modern, spill-proof industrial design. The hardware-only digital outputs connect directly to a 3.3 V MCU GPIO bank with no firmware touch-processing stack required, reducing BOM cost and time-to-market. The on-die advanced noise-suppression algorithm rejects interference from class-D amplifier switching edges and SMPS ripple that share the same chassis, which the datasheet identifies as a key robustness benefit. The MTPM pin allows low-power standby between user interactions, which is important for ENERGY STAR compliance on AV receivers and soundbars.
Recommended
Recommended Products Summary
Engineering reference data for MTCH108/SS — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | MTCH108T-I/SS | MTCH105-I/SS | MTCH102-I/MS |
|---|---|---|---|---|
| Brand | Microchip Technology | Microchip Technology | Microchip Technology | Microchip Technology |
| Package | SSOP-20 | SSOP-20 - same | SSOP-20 - same | MSOP-10 - different (NOT drop-in) |
| Number of Channels | 8 | 8 (same) | 5 (-37.5%) | 2 (-75%) |
| Operating Voltage | 2.05 V to 3.6 V | 2.05 V to 3.6 V (same) | 2.05 V to 3.6 V (same) | 2.05 V to 3.6 V (same) |
| Output Type | 8 active-high digital GPIO | 8 active-high digital GPIO (same) | 5 active-high digital GPIO | 2 active-high digital GPIO |
| Noise Suppression Algorithm | On-die advanced optimization | On-die advanced optimization (same) | On-die advanced optimization (same) | On-die advanced optimization (same) |
| Guard-Ring Driver | Integrated | Integrated (same) | Integrated (same) | Integrated (same) |
| Operating Temperature | -40C to +85C | -40C to +85C (same) | -40C to +85C (same) | -40C to +85C (same) |
Key Differentiators
- Pure hardware-only logic outputs with no MCU firmware overhead (vs NXP MPR121)
- Same-family channel-count scalability on identical SSOP-20 footprint (vs MTCH1060T-I/SS)
- Integrated advanced noise-suppression algorithm in pure analog domain (vs Generic discrete touch ICs)
Design Notes
Place a 100 nF X7R ceramic decoupling capacitor within 5 mm of the MTCH108 VDD pin (pin 19) and connect its ground lead directly to the GND pin (pin 20) with a short, wide trace. Route the 8 capacitive sensor traces (CH0-CH7) as short as possible - ideally under 50 mm - and keep them away from switching converter edges, clock lines, and high-current power traces. Each sensor pad should be a hatched or solid copper pour sized between 8 mm x 8 mm and 15 mm x 15 mm, with the ground-hatched spacing set per Microchip's PCB layout application note.
Use Microchip's recommended guard-ring pattern surrounding each sensor pad, tied to the MTCH108 internal guard-ring driver pin. The guard ring dramatically reduces moisture and water-droplet false triggers, which is essential for appliance and outdoor applications. Keep the sensor pads and guard ring on the top copper layer only - do not route any signal traces under the pads - and use a thin (1-2 mm) overlay material such as glass, acrylic, or polycarbonate for the user interface. Thicker overlays require recalibration via the MTSA pin setting.
Do not exceed 3.6 V on VDD - the MTCH108 absolute maximum is 4.0 V but operation above 3.6 V is not characterized and may damage the analog front-end. Do not leave the MTPM and MTSA pins floating - tie them high or low per the desired sensitivity/power mode, or noise pickup on these high-impedance pins will cause random false triggers. Do not place the IC on the same PCB region as a switching DC-DC converter without filtering, as the 2.05 V to 3.6 V analog supply is sensitive to common-mode ripple above 100 mVpp.
If the MTCH108 outputs must drive cables longer than 50 mm to a remote MCU, add a 100 ohm series resistor at each OUTx pin to dampen transmission-line ringing, and place a 10 kohm pull-up to VDD at the far end. The OUTx outputs are push-pull CMOS and source/sink several mA, so they can drive short PCB traces directly but should be buffered if connected to long cables or capacitive loads above 30 pF.
Compliance Information
RoHS and REACH compliant per Microchip product page; industrial temperature grade (-40C to +85C) only - not AEC-Q100 qualified. For automotive applications requiring AEC-Q100, choose the MTCH108T-I/SS or contact Microchip for automotive-qualified variants.
